Quality of life and cost-effectiveness of convalescent plasma compared to standard care for hospitalized COVID-19 patients in the CONCOR-1 trial

BACKGROUND

The CONvalescent Plasma for Hospitalized Adults With COVID-19 Respiratory Illness (CONCOR-1) trial was a multicenter randomized controlled trial assessing convalescent plasma in hospitalized COVID-19 patients. This study evaluates the cost-effectiveness of convalescent plasma and its impact on quality-of-life to provide insight into its potential as an alternative treatment in resource-constrained settings.

METHODS

Individual patient data on health outcomes and resource utilization from the CONCOR-1 trial were used to conduct the analysis from the Canadian public payer's perspective with a time horizon of 30 days post-randomization. Baseline and 30-day EQ-5D-5L were measured to calculate quality-adjusted survival. All costs are presented in 2021 Canadian dollars. The base case assessed the EQ-5D-5L scores of hospitalized inpatients reporting at both timepoints, and a utility score of 0 was assigned for patients who died within 30 days. Costs for all patients enrolled were used. The sensitivity analysis utilizes EQ-5D-5L scores from the same population but only uses costs from this population.

RESULTS

940 patients were randomized: 627 received CCP and 313 received standard care. The total costs were $28,716 (standard deviation, $25,380) and $24,258 ($22,939) for the convalescent plasma and standard care arms respectively. EQ-5D-5L scores were 0.61 in both arms (p = .85) at baseline. At 30 days, EQ-5D-5L scores were 0.63 and 0.64 for patients in the convalescent plasma and standard care arms, respectively (p = .46). The incremental cost was $4458 and the incremental quality-adjusted life day was -0.078.

DISCUSSION

Convalescent plasma was less effective and more costly than standard care in treating hospitalized COVID-19.

DRUG RELATED NITROSOGENESIS, PHOTOCARCINOGENESIS AND ONCOPHARMACOGENESIS OF NODULAR MELANOMA: A CASE RELATED ANALYSIS CONCERNING THE POLYCONTAMINATION OF THE POLYMEDICATION WITH VALSARTAN/HYDROCHLOROTHIAZIDE AND BISOPROLOL

Despite the fact that the pathogenesis of cutaneous melanoma is shrouded in mystery, factors that have been neglected or unnoticed until now have come to the attention in recent years, and in all likelihood, they could also be pivotal. These factors, known as nitrosamines or NDSRIs, are characterized by high carcinogenic and mutagenic potency, and some of them have demonstrated these properties to human DNA as well. Unfortunately, these ingredients also turn up as contaminants in about 300 of the most widely distributed drugs worldwide. According to the most recent literature, some of these ingredients are also identified as potent photocarcinogens, as well as human carcinogens. The intake of these carcinogens in the context of polycontamination of polymedication, has been associated for years with the occurrence of melanomas. The need for cataloguing of nitrosamines , as well as their accurate labelling on drug packaging, would help to classify them even more accurately as carcinogens affecting human DNA. We present once again a patient , who developed nodular melanoma within the context of the intake of 3 potentially nitrosamine/ NDSRIs contaminated antihypertensive drugs (valsartan/ Hydrochlorothiazide/ bisoprolol). Pathogenetic aspects concerning drug-induced nitrosogenesis, photocarcinogenesis and oncopharmacogenesis of skin cancer are discussed. Nitrosogenesis' of Cancer as concept in the medical literature has been known for decades, but in relation to other forms of human cancer. Exogenously mediated drug-mediated nitrosogenesis is a logically conditioned and newly defined concept whose significance with respect to the clinical manifestation of skin cancer is only beginning to grow.

When a little flutter gets a bit too exciting…

A middle-aged man with no previous cardiac history was admitted to the hospital being treated for thigh cellulitis, during his stay he developed palpitations and tachycardia which on initial ECG showed atrial flutter with a 2:1 AV block and evidence of an accessory pathway. He was subsequently given AV nodal blocking agents in the form of beta-blockers (bisoprolol) to slow his heart rate down; unfortunately, this led to hemodynamic instability due to 1:1 conduction of the atrial flutter down the accessory pathway. This case report demonstrates the importance of recognising pre-excitation on an ECG and the potential adverse effect of administering AV nodal blockade.

Effect of Concomitant Drugs on Sodium Zirconium Cyclosilicate Hydrate in Artificial Intestinal Juice

To explore drug interactions involving sodium zirconium cyclosilicate hydrate (SZC) and concomitant drugs like calcium antagonists (amlodipine and nifedipine) and β-blockers (carvedilol and bisoprolol), we investigate how these concomitant drugs influenced the administration of SZC in an artificial intestinal juice. Initially, we assessed the potassium ion adsorption capacity, ranking it as follows: calcium polystyrene sulfonate (CPS, 54.9 mg/g) < sodium polystyrene sulfonate (SPS, 62.1 mg/g) < SZC (90.8 mg/g). However, the adsorption equilibrium was achieved in the order of CPS ≒ SPS (within 1 min) < SZC (within 1 h). Subsequently, we determined the residual percentages of amlodipine, nifedipine, carvedilol, and bisoprolol, finding them to be 79.0-91.9% for SZC, 0.38-38.4% for SPS, and 0.57-29.0% for CPS. These results suggest the efficacy of SZC in managing hyperkalemia alongside concomitant drugs in an artificial intestinal juice, with particular emphasis on amlodipine (calcium antagonist) and carvedilol (β-blocker). Additionally, we identified the presence of carbon, nitrogen, and oxygen components from both drugs on the SZC surface following interaction. We also evaluated how amlodipine, nifedipine, carvedilol, and bisoprolol affected the administration of SZC in the presence of potassium ions. Our results indicate that potassium ions and concomitant drugs did not interfere with each other in the artificial intestinal juice. These results offer valuable insights into the administration of SZC in conjunction with concomitant drugs. Lastly, the presented data shows qualitative results in this study.

Further exploration of the collision-induced dissociation of select beta blockers: Acebutolol, atenolol, bisoprolol, carteolol, and labetalol

Beta blockers are a class of drugs commonly used to treat heart-related diseases; they are also regulated under the World Anti-Doping Agency. Tandem mass spectrometry is often used in the pharmaceutical industry, clinical analysis laboratory, and antidoping laboratory for detection and characterization of drugs and their metabolites. A deeper chemical understanding of dissociation pathways may eventually lead to an improved ability to predict tandem mass spectra of compounds based strictly on their chemical structure (or vice versa), which is especially important for characterization of unknowns such as emerging designer drugs or novel metabolites. In addition to providing insights into dissociation pathways, the use of energy-resolved breakdown curves can produce improved selectivity and lend insights into optimal fragmentation conditions for liquid chromatography-tandem mass spectrometry LC-MS/MS workflows. Here, we perform energy-resolved collision cell and multistage ion trap collision-induced dissociation-mass spectrometry (CID-MS) experiments, along with complementary density functional theory calculations, on five beta blockers (acebutolol, atenolol, bisoprolol, carteolol, and labetalol), to better understand the details of the pathways giving rise to the observed MS/MS patterns. Results from this work are contextualized within previously reported literature on these compounds. New insights into the formation of the characteristic product ion m/z 116 and the pathway leading to characteristic loss of 77 u are highlighted. We also present comparisons of breakdown curves obtained via qToF, quadrupole ion trap, and in-source CID, allowing for differences between the data to be noted and providing a step toward allowing for improved selectivity of breakdown curves to be realized on simple instruments such as single quadrupoles or ion traps.

Does preoperative administration of hypotensive agents affect the quality of the surgical field during endoscopic sinus surgery? A triple-blind randomized controlled trial

PURPOSE

Endoscopic sinus surgery (ESS) is a surgical procedure widely used in the treatment of various sinonasal conditions. Excessive bleeding during ESS leads to potentially major complications. The primary aim of this trial was to explore any different effects of bisoprolol and nifedipine on the intraoperative surgical field. In addition, the correlations regarding surgical field state, total blood loss (TBL), mean arterial pressure (MAP), and heart rate (HR) were also examined.

METHODS

A prospective, triple-blinded, randomized, placebo-controlled trial was conducted, including 72 patients between 18 and 65 years of age who underwent ESS. As an indicator of the worst state of the intraoperative surgical field, the Boezaart scale score was used, as evaluated by two surgeons. Appropriate statistical analysis was conducted to explore score comparisons across groups and correlations between vital signs, bleeding, and the operative field state.

RESULTS

No statistically significant difference was found among different intervention groups regarding the worst state of the surgical field (p = 0.367 > 0.05). The Boezaart scale score was positively correlated with TBL (rxy = 0.619, p = 0.000 < 0.001) and MAP (rxy = 0.259, p = 0.028 < 0.05). Furthermore, MAP was positively correlated with HR (rs = 0.254, p = 0.32 < 0.05).

CONCLUSION

Our study demonstrates that preoperative administration of bisoprolol and nifedipine does not affect the worst state of the operative field. However, vital signs seem to either directly or indirectly affect bleeding and operative field state, and agents affecting them are worth exploring further.

METASTATIC NODULAR MELANOMA DEVELOPING ON NEVUS SPILUS DURING INTAKE OF BETA BLOCKERS (BISOPROLOL/NEBIVOLOL) AND ACE INHIBITORS (PERINDOPRIL). POTENTIAL LINKS TО THE DRUG RELATED NITROSOGENESIS/CARCINOGENESIS, DUNNING-KRUGER EFFECT AND GENETIC WEAPONS OF THE NEW GENERATION

Drug-induced Nitrosogenesis/Carcinogenesis turns out to be a ubiquitous, pervasive, large-scale, poorly controllable concept for the academic community, which underlies the long-term, permanent modification of the human genome by contact with nitrosamines/NDSRIs, which ultimately leads to the generation of diverse cancers, but also melanoma in particular. The discovery of a (currently) unclassifiable number of nitroso derivatives/genome modifiers in the most commonly distributed drugs worldwide (in about 300 preparations according to the FDA/includes beta blockers/bisoprolol/nebivolol and ACE inhibitors/perindopril), their forced tolerability, attributed as a necessity or lack of alternative also to the present (but also to future periods), and their proven carcinogenicity (already 70 years ago), suggest a kind of creepy form of experiment to which public health is subjected worldwide. The creation of a universal nitroso-comfort of pharmaceutical companies and the regulation of a permanent intake of carcinogens in drugs for years to come, but also decades back, suggest possible cartel agreements between the regulation/distribution unit and that of production cycles. These "agreements" are becoming increasingly evident and in all likelihood position nitrosogenesis from a until recently unknown element, to a pathogenetic factor of paramount importance. Melanoma could be viewed precisely as the controlled end gene-modified product of drug-mediated nitrosogenesis/carcinogenesis, proven to be a locoregional (but not only) phenomenon hundreds if not thousands of times. The dilemma stays: Are the nitrosamines in drugs genetic weapons, ethnic bioweapons for silent war ? The nitrosogenesis concerning melanoma leads to the logical conclusion that cancer is in fact a largely controlled set event or, according to others, a forced necessity of evolutionary globalization processes to purge the population in certain regions. In favor of this statement indicative are namely: 1) lack of regulatory control/results of such conducted, 2) complete information veil for the end user regarding contamination with carcinogens/nitrosamines in certain batches or all batches of drugs, 3) misinformation and lack of transparency regarding the concept of nitrosogenesis also for the academic community, as well as 4) the impunity to pharmaceutical conglomerates after criminal negligence/controlled criminogenicity proven thousands of times by the FDA/EMA leading to regulatory controlled drug mediated genocide of the human population in certain areas on a daily basis. And most important of all: 5) the lack of refusal to eliminate these drugs, i.e. - the imposition of forced tolerance at any cost. It is extremely unfortunate that the mentioned and identified grotesque/situation, its tolerance on a global scale, lead to a misjudgement of the significance of real tumor inducers within the global health map//statistics as well as melanoma. The focus of prevention is being displaced, while the incidence of cancer in general and that of melanoma is skyrocketing. Nitrosamines could be defined as the newest, modern, until recently invisible and unknown, but -controllable form of genetic weapon to modify the human genome. Because of these very facts, the likelihood that clinicians and the academic community are in the frozen and permanent state of the Dunning-Kruger effect is very real. Certain globalization regulatory elements create problems and assignments that must be solved ˝competently˝ by incompetent, fully regulatable compartments. As their state of competence depends again and entirely on ˝their incompetence˝. Until now. After the formalization of the concept of Nitrosogenesis (as a form of genetic weapon) and melanoma for example, but not only, it remains to be seen whether universal incompetence will become a guarantee of competence and the survival. Or- will it remain again at the level of globalized, criminally conditioned, appointed and regulated from above "competent incompetence". The dilemmas to regulators and manufacturers remain open : Is it competent to take drugs that contain carcinogens/nitrosamines? Is it competent for this issue to continue for decades with impunity? Is it competent for regulators not to inform consumers about the presence of carcinogens/genome modifiers in medicines for decades? Is it competent for certain regions to be affected by nitrosamine contamination and not others? Is it competent not to reflect this in regional and global health bulletins on side effects? Is it competent to make thousands of times the profits from the modified genetic map business, regulated and legally initiated through the intake of carcinogens? Is it competent to have the concentration of carcinogens within polymedication exceeding many times the daily allowable doses of carcinogens and have no solution for this? Is it competent, when the intake of nitrosamines in medicines is associated with the generation of melanomas and heterogeneous cancers- to have no alternative to this or when one is available- to conceal it skillfully? Is it competent to determine carcinogenic activity based on mutagenic tests? Is it competent to be polyincompetent within a framework of mass (in)competence? We report systemically administered drugs for the treatment of high blood pressure from the group of beta blockers (bisoprolol/nebivolol) and ACE inhibitors (perindopril) that have been identified by regulators in the face of FDA as hypothetically contaminated with nitrosamines/NDSRIs with a carcinogenic potency between 4 and 5, respectively. Within this cumulative intake, (which according to the regulators was not at risk of developing cancerous forms), similar to other cases in the world literature, the patient developed a relatively short-term, metastatic nevus spilus-based nodular melanoma. The paper analyses not only the role of nitrosogenesis, but also that of two pregnancies and painful sunburns as potential cofactors for melanoma genesis. Academic attention is drawn to the potential impact of drug-mediated nitrosogenesis/carcinogenesis. Nitrosamines in the framework of polycontamination and polymedication could also be identified as one of the most effective, until recently unknown, modern generation genetic weapons for modifying the human genome and controlling cancer. Moreover, they could be controllably applied and skillfully targeted. At least until now. The officialization of carcinogens in more than 250 of the most common drugs and the clinico-pathological correlations concerning the development of cancer/melanoma in poorly controlled geographical regions represent a kind of in vivo prospective study to determine precisely the real carcinogenic role of nitrosamines to date.

CONTAMINATION OF VENLAFAXINE, BISOPROLOL AND OLANZAPINE WITH NITROSAMINES/NDSRIS: THE MOST LIKELY CAUSE OF SKIN CANCER DEVELOPMENT AND PROGRESSION

Two steps are able to lead to a significant decrease in the incidence of skin cancer overall and/or to its parallel and successful surgical treatment. The first step concerns its non-occurrence or less frequent clinical manifestation and is largely related to the modern concept known as prevention, but not the one mainly related to solar radiation, but: 1) informing patients about the possible contamination of certain drugs with carcinogens/nitrosamines/NDSRIs and 2) making clinicians aware of the modern concept of limited to completely eliminated intake of nitrosamines/NDSRIs in medications. The ineffectiveness of either of these entities could in all likelihood be seen as one of the major causes of the headline growth in the incidence of skin cancer and keratinocytic cancer in particular. It is also because of this fact that the sun protection so recommended and advertised has been shown to be ineffective, yet it remains universally advertised. Polycontamination with Nitrosamines/NDSRIs within multimedication in polymorbid patients is the most serious obstacle (at the moment) for the current concept of skin cancer prevention to become a reality. The announced official "hypothetical contamination" of more than 250 drugs worldwide by the FDA in April 2023, and the establishment of permissive concentrations for 5 classes of carcinogenic activity of the nitrosamines/NDSRIs - effectively make any preventive step more than impossible or meaningless. The open question remains, how were the 5 subgroups for hypothetical carcinogenic potency of the carcinogens contained in the drugs created? On the basis of what data? What tumors occurred when these concentrations were exceeded? Data that remains hidden from the public and end users, but also data that guarantees the development of real (not hypothetical) skin tumours. The new FDA regulations also do not comment on the issues concerning the use of "hypothetical carcinogens" in the context of polycontamination and polymedication in polymorbid patients. Because of this fact, the follow-up of actual carcinomas after the intake of multiple "hypothetical carcinogens" would also seem to be not unimportant. And it turns out to be quite real and sobering to say the least. The second step, which concerns the successful treatment of skin cancer, is its early surgical treatment. This is the most promising approach, regardless of whether patients are exposed to permanent intake of carcinogens/nitrosamines/NDSRIs in the drugs. We report an 86-year-old patient, who, as part of his polymedication and polymorbidity, takes 3 drugs that, according to the official FDA list of 2023, have strictly defined reference limits for potentially available "hypothetical carcinogens": bisoprolol/carcinogenic potency class 4, olanzapine/ carcinogenic potency class 5 and venlafaxine/ carcinogenic potency class 1. The described patient developed "real carcinoma" after combined long-term intake of the "hypothetical carcinogens" announced in the official FDA lists from April 2023. Proceeding from common sense, regulators in the face of the FDA should have already long observed the development of a heterogeneous type of tumors to be able to determine 1) the potency of the 5 subclasses of carcinogens in the drugs and 2) their reference values. Moreover- they should also have the exact information why which carcinogen in which drug causes which type of tumor. Otherwise, the FDA should not announce its detailed recommendations to drug manufacturers. The present patient was successfully treated surgically by a transposition adjacent flap. The optimal dermatosurgical and reconstructive methodologies for the treatment of tumors in the ala nasi area are discussed.

LC-MS/MS bioanalytical method for the quantitative analysis of nifedipine, bisoprolol, and captopril in human plasma: Application to pharmacokinetic studies

In this study, the development and validation of an accurate and highly sensitive LC-MS/MS method were performed for the estimation of nifedipine, bisoprolol and captopril in real human plasma. Liquid-liquid extraction using tert-butyl methyl ether was efficiently applied for extraction of the analytes from plasma samples. The chromatographic separation was carried out using an isocratic elution mode on the X-terra MS C18 column (4.6 × 50 mm, 3.5 μm). The mobile phase consisted of methanol-0.1% formic acid (95:5, v/v) for determination of nifedipine and bisoprolol and acetonitrile-0.1% formic acid (70:30, v/v) for determination of captopril with a flow rate of 0.5 ml/min. Acceptable results regarding the different validation characteristics of the analytes were obtained in accordance with US Food and Drug Administration recommendations for bioanalytical methods. The developed approach was linear over concentration ranges of 0.5-130.0, 50.0-4,500.0 and 0.3-30.0 ng/ml for nifedipine, captopril and bisoprolol, respectively. The method revealed a sufficient lower limit of quantification in the range of 0.3-50.0 ng/ml, as well as high recovery percentages, indicating high bioanalytical applicability. The proposed method was efficiently applied to a pharmacokinetic evaluation of a fixed-dose combination of the analytes in healthy male volunteers.

NITROSAMINES IN COMMONLY PRESCRIBED ANTIHYPERTENSIVES AND THE (UN)CONTROLLED DRUG-INDUCED SKIN CANCER: SIMULTANEOUS DEVELOPMENT OF CUTANEOUS MELANOMA AND MULTIPLE BCC AFTER CONCOMITANT ADMINISTRATION OF BISOPROLOL AND FUROSEMIDE

The era of nitrosogenesis is the era that is conditioned by the permanent and prolonged intake of carcinogens/mutagens, also known as nitrosamines/NDSRIs in the context of polymedication/polycontamination in polymorbid patients. Until recently, the favoured and universally accepted thesis by the scientific community that polymorbidity determines the risk of developing cancer has been shown to be weakly substantiated and superseded by the more modern notion that: it is the polycontamination with carcinogens in the context of concomitant medication/ polymorbidity that determines to a large extent the risk of developing heterogeneous cancers, including skin cancer: keratinocytic and melanocytic. The FDA is the organization that first pulled back the curtain on the backstage back in 2018 on this topic. It was not until 2023 that the FDA again catalogued over 250 drugs that are affected by contamination with carcinogens/mutagens/NDSRIs having varying carcinogenic potencies graded between 1 to 5. The expectations of clinicians and patients globally at the moment remain hopeful that the diplomatic recommendations of regulators will soon be replaced by more restrictive regimes and sanctions. The reason for the need to clarify this issue quickly is due to the following circumstances: 1) The reassuring calls and analyses of the regulators that the minimum intake of carcinogens ( nitrosamines or intake within reference values) , could not become a threat to the health of patients even after 70 years of intake, appear to be rather inconsistent; 2) Lack of any official data on any drug batch that has at least been declared by the FDA/EMA (if declared at all) as potentially contaminated; 3) Another not insignificant reason is that a number of scientific publications are indicative of exactly the opposite: short-term concomitant intake of polycontaminated drugs leads to short-term cancer development while shortening cumulative survival and quality of life for those affected. Only the transparency of the results of checks carried out on the presence of carcinogens in drug batches can guarantee peace of mind, and this in turn can be guaranteed by the regulatory authorities. 4) In parallel, the number of clinical data indicating an association between the intake of potentially nitrosamine-contaminated drugs (mainly for high blood pressure, but not only) and - in particular - keratinocytic and/or melanocytic skin cancer is growing avalanche-like. The dramatic increase in skin cancer in general/ worldwide is in absolute contradiction to the continuous explanations that the most important factor in the generation of skin cancer is ultraviolet light and sunburn: the incidence of skin cancer is increasing despite the widespread intensive use of sunscreen protection creams, the lack of any sun exposure in certain groups of patients, and its occurrence in areas not exposed to solar radiation. It follows only that solar radiation is not the only and perhaps not the most important factor determining the occurrence and progression of skin cancer. We report another concomitant intake of potentially nitrosamine contaminated blood pressure medications: bisoprolol and furosemide, taken over a period of 7 years that resulted in the concurrent occurrence of a medium-thickness cutaneous melanoma and 2 basal cell carcinomas. Successful surgical treatment of the tumors was performed, and the role of concurrent administration of ˝hypothetical˝ class 4 carcinogens within the framework of polymedication, polycontamination, and polymorbidity is discussed.

Elevated Blood Pressure Occurs without Endothelial Dysfunction in a Rat Model of Pulmonary Emphysema

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease involving airway closure and parenchyma destruction (emphysema). Cardiovascular diseases are the main causes of morbi-mortality in COPD and, in particular, hypertension and heart failure with preserved ejection fraction (HFpEF). However, no mechanistic link has currently been established between the onset of COPD, elevated blood pressure (BP) and systemic vascular impairment (endothelial dysfunction). Thus, we aimed to characterize BP and vascular function and remodeling in a rat model of exacerbated emphysema focusing on the role of sympathetic hyperactivity. Emphysema was induced in male Wistar rats by four weekly pulmonary instillations of elastase (4UI) and exacerbation by a single dose of lipopolysaccharides (LPS). Five weeks following the last instillation, in vivo and ex vivo cardiac and vascular functions were investigated. Exacerbated emphysema induced cardiac dysfunction (HFpEF) and a BP increase in this COPD model. We observed vasomotor changes and hypotrophic remodeling of the aorta without endothelial dysfunction. Indeed, changes in contractile and vasorelaxant properties, though endothelium-dependent, were pro-relaxant and NO-independent. A β1-receptor antagonist (bisoprolol) prevented HFpEF and vascular adaptations, while the effect on BP increase was partial. Endothelial dysfunction would not trigger hypertension and HFpEF in COPD. Vascular changes appeared as an adaptation to the increased BP. The preventing effect of bisoprolol revealed a pivotal role of sympathetic hyperactivation in BP elevation. The mechanistic link between HFpEF, cardiac sympathetic activation and BP deserves further studies in this exacerbated-emphysema model, as well as in COPD patients.

Kinetic analysis of endogenous β2 -adrenoceptor-mediated cAMP GloSensor™ responses in HEK293 cells

BACKGROUND AND AIM

Standard pharmacological analysis of agonist activity utilises measurements of receptor-mediated responses at a set time-point, or at the peak response level, to characterise ligands. However, the occurrence of non-equilibrium conditions may dramatically impact the properties of the response being measured. Here we have analysed the initial kinetic phases of cAMP responses to β2 -adrenoceptor agonists in HEK293 cells expressing the endogenous β2 -adrenoceptor at extremely low levels.

EXPERIMENTAL APPROACH

The kinetics of β2 -adrenoceptor agonist-stimulated cAMP responses were monitored in real-time, in the presence and absence of antagonists, in HEK293 cells expressing the cAMP GloSensor™ biosensor. Potency (EC50 ) and efficacy (Emax ) values were determined at the peak of the agonist GloSensor™ response and compared to kinetic parameters L50 and IRmax values derived from initial response rates.

KEY RESULTS

The partial agonists salbutamol and salmeterol displayed reduced relative IRmax values (with respect to isoprenaline) when compared with their Emax values. Except for the fast dissociating bisoprolol, preincubation with β2 -adrenoceptor antagonists produced a large reduction in the isoprenaline peak response due to a state of hemi-equilibrium in this low receptor reserve system. This effect was exacerbated when IRmax parameters were measured. Furthermore, bisoprolol produced a large reduction in isoprenaline IRmax consistent with its short residence time.

CONCLUSIONS AND IMPLICATIONS

Kinetic analysis of real-time signalling data can provide valuable insights into the hemi-equilibria that can occur in low receptor reserve systems with agonist-antagonist interactions, due to incomplete dissociation of antagonist whilst the peak agonist response is developing.

Patient-friendly extemporaneous formulation of bisoprolol: application to stability and bioavailability studies

Community and hospital pharmacists always face the challenge to prepare oral liquid extemporaneous formulations to fit the needs of a specific patient population when commercial forms or the required strength is unavailable. This study was performed to prepare a stable patient-friendly oral liquid extemporaneous formulation of bisoprolol. Eight different extemporaneous formulations were prepared using various suspending agent(s). The in vitro dissolution of all extemporaneous formulations was examined. A comprehensive accelerated stability study was carried out to evaluate the adequate beyond-use date of the most optimized extemporaneous formulation. A validated ultra-performance liquid chromatography method was used for the analysis and quantification of bisoprolol in the accelerated stability and bioavailability studies. A group of eight healthy volunteers was enrolled in a two-way cross-over experimental design to study the bioavailability of the most optimized extemporaneous formulation. The pharmacokinetic parameters of bisoprolol were estimated. Extemporaneous suspension containing 0.5% w/v xanthan gum was easily prepared with a simple, natural, safe, sugar-free excipients. It achieved the best dissolution behavior among other extemporaneous suspensions. It was an easily pourable viscous suspension with no sedimentation. At least 98% of the initial concentration of bisoprolol remained throughout the 6-month study period in the selected suspension regardless of the storage conditions. There was no perceptible change in color, odor, or taste, and no noticeable microbial growth was observed in any sample. The selected formulation was bioequivalent to the commercial tablet in terms of the rate and extent of absorption. This research may be of great help during development of appropriate extemporaneous formulation of bisoprolol fumarate. The simple preparation method could be utilized to draw up a standard operating procedure (SOP) easy to use by different types of pharmacy settings.

Novel Deconvoluted Synchronous Spectrofluorimetric Method For Simultaneous Determination Of Bisoprolol and Atorvastatin As Single or Co-administrated Drugs in Bulk and Plasma; Green Assessment

Atorvastatin and bisoprolol are two medications often prescribed together for the management of cardiovascular disease and to reduce mortality. Through a simple and direct technique based on deconvolution and synchronous of the spectrofluorometric spectra, the innovative method enables simultaneous quantification of bisoprolol and atorvastatin as single or co-formulated dosage forms in bulk and plasma. The method depends on measuring the amplitudes of bisoprolol and atorvastatin at 298 nm and 363 nm directly after deconvolution where the other drug doesn't show interference. The linearity of the method was 0.02-0.5 µg/mL and 0.3-25 µg/mL for bisoprolol and atorvastatin, respectively. LOD and LOQ were 0.004, 0.085 µg/mL and 0.013, 0.259 µg/mL for bisoprolol and atorvastatin respectively. Furthermore, green assessment of the method using Eco-Scale and GAPI scale. The method was precise, economical, simple, smart, time-saving and eco-friendly, which allowed its application in quality control unit and in lab assessment.

Potential Interaction between Sodium Polystyrene Sulfonate and Prescription Drugs in Artificial Intestinal Juice

This study evaluated the interaction between sodium polystyrene sulfonate (SPS) and several commonly used concomitant drugs, such as carvedilol, bisoprolol, imidapril, atorvastatin and azilsartan. The residual rate of adsorption 6 h after starting the experiment followed the order carvedilol (0.36%) < bisoprolol (19.7%) < imidapril (81.2%) < atorvastatin (86.5%) < azilsartan (87.9%) in artificial intestinal juice (pH 6.8). In addition, the pKa of carvedilol and bisoprolol was 8.0 and 9.6 and that of atorvastatin, azilsartan, and imidapril was 4.5, 6.1, and 2.4, respectively. These results indicate that the form (ionic or uncharged) of each drug is important to its reaction with SPS. Moreover, we demonstrated the effect of potassium ions (concentration of 1000 or 2000 mg/L) on the adsorption of concomitant drugs onto SPS in artificial intestinal juice. Our results show that the residual rate of adsorption of carvedilol and bisoprolol increases with increasing concentration of potassium ions whereas adsorption of potassium ions onto SPS was unaffected by carvedilol and bisoprolol under our experimental conditions. Finally, the obtained results revealed that interactions between SPS and carvedilol or bisoprolol readily occur in artificial intestinal juice.

Co-prescription of metoprolol and CYP2D6-inhibiting antidepressants before and after implementation of an optimized drug interaction database in Norway

Purpose

To compare the co-prescription of metoprolol and potent CYP2D6-inhibiting antidepressants before and during a 10-year period after implementation of an optimized drug interaction database into clinical decision support systems in Norway.

Methods

The study was a retrospective, cross-sequential nationwide analysis of drug-dispensing data retrieved from the Norwegian Prescription Database over a 1-year period before (2007) and two 1-year periods after (2012 and 2017) implementation of a drug interaction database providing recommendations on non-interacting alternative medications. Primary outcome was changes in co-prescription rates of metoprolol and the potent CYP2D6-inhibiting antidepressants fluoxetine, paroxetine, or bupropion relative to alternative antidepressants with no or limited CYP2D6 inhibitory potential. To control for potential secular trend bias, a comparison group consisting of atenolol/bisoprolol users was included.

Results

The co-prescription rate of metoprolol with potent CYP2D6 inhibitors declined following implementation of the optimized database, by 21% (P < 0.001) after 5 years and by 40% (P < 0.001) after 10 years. Compared with atenolol/bisoprolol users, patients treated with metoprolol had significantly reduced likelihood of being prescribed a CYP2D6-inhibiting antidepressant in the two post-implementation periods (OR 0.61 (95% CI 0.54–0.69) and OR 0.45 (95% CI 0.40–0.51), respectively, versus OR 0.84 (95% CI 0.74–0.94) prior to implementation). Small and mostly insignificant differences in average daily metoprolol dosage were found between patients treated with the various antidepressants.

Conclusion

The present study suggests that implementation of a drug interaction database providing recommendations on non-interacting drug alternatives contributes to reduced co-prescribing of drug combinations associated with potentially serious adverse effects.

Advanced chemometric methods as powerful tools for impurity profiling of drug substances and drug products: Application on bisoprolol and perindopril binary mixture

Impurity profiling has a rising importance nowadays due to the increased health problems associated with impurities and degradation products found in several drug substances and formulations. Three advanced, accurate and precise chemometric methods were developed as impurity profiling methods for a mixture of bisoprolol fumarate (BIS) and perindopril arginine (PER) with their degradation products which represent drug impurity or a precursor to such impurity. The methods applied were Partial Least Squares (PLS-1), Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and Artificial Neural Networks (ANN). Genetic Algorithm (GA) was used as a variable selection tool to select the most significant wavelengths for the three chemometric models. For proper analysis, a 5-factor 5-level experimental design was used to establish a calibration set of 25 mixtures containing different ratios of the drugs and their degradation products (impurities). The validity of the proposed methods was assessed using an independent validation set. The designed models were able to predict the concentrations of the drugs and the degradation products/impurities in the validation set and pharmaceutical formulation. The proposed methods presented a powerful alternative to traditional and expensive chromatographic methods as impurity profiling tools.

The possibilities of using beta-blocker bisoprolol in patients with stable angina with concomitant bronchial asthma

Aim    To compare efficacy and safety of treatments with the calcium antagonist (CA) verapamil, the cardioselective β-blocker (BB) bisoprolol, and a combination therapy with bisoprolol and amlodipine in patients with stable angina (SA) with concurrent mild and moderate, persistent bronchial asthma (BA). Material and methods    This open, prospective, randomized, comparative study included 120 patients with an IHD+BA comorbidity. Of these patients, 60 had mild persistent BA and 60 had moderate persistent BA. Each group was divided into 3 subgroup, each including 20 patients, based on the used regimen of antianginal therapy. Stepwise dose titration was performed every 2 weeks (subgroup 1 received the BB bisoprolol 2.5 mg - 5 mg - 10 mg; subgroup 2 received the CA verapamil 240 mg - 240 mg - 240 mg; subgroup 3 received bisoprolol 2.5 mg followed by the combination treatment with bisoprolol and amlodipine as a fixed combination 5+5 mg). All patients underwent a complete clinical and instrumental examination at baseline and at 2, 4, and 6 weeks of treatment. The antianginal effectivity and the effect on bronchial patency were evaluated. Results    In patients with SA and mild persistent BA, the study of external respiration function (ERF) at 2, 4, and 6 weeks of treatment did not detect any significant difference in the forced expiratory volume in 1 second (FEV1) between the treatment subgroups. In patients with SA and moderate persistent BA receiving the treatment, a significant decrease in FEV1 (р=0.022) was observed in subgroup 1 receiving bisoprolol 10 mg at 6 weeks of treatment. In subgroups 2 and 3 during the treatment, significant differences were absent. In patients with SA and mild or moderate persistent BA, the heart rate was significantly decreased in all three subgroups; however, in subgroup 2 receiving verapamil, the changes were considerably smaller than in other subgroups.Conclusion    The study results showed that the BB bisoprolol with dose titration every two weeks from 2.5 to 10 mg or the combination treatment with the BB bisoprolol and the CA amlodipine can be used as the antianginal therapy in patients with SA and mild persistent BA. The BB bisoprolol may be used in patients with SA and moderate persistent BA as the antianginal therapy, but only at doses not exceeding 5 mg to avoid the development of bronchial obstruction. The combination therapy with the BB bisoprolol 5 mg and the CA amlodipine 5 mg is indicated to enhance antianginal and vasoprotective effects.

[Transudative chylothorax complicated with liver cirrhosis due to primary biliary cholangitis:case report]

A 70-year-old woman who was diagnosed with liver cirrhosis as a result of primary biliary cholangitis and heart failure by myocardial infarction 1 month ago complained of dyspnea and was admitted to our hospital. Image inspections showed right massive pleural effusion, so we performed thoracentesis and drainage. Despite no history of trauma or malignancy, we obtained milky white-yellow pleural effusion by drainage and it turned out to be transudative chylothorax. Because there were no signs of heart failure exacerbation or other diseases, we suspected that the transudative chylothorax was caused by liver cirrhosis. For cardioprotection and improvement of portal hypertension, we used conservative treatments such as increasing diuretic dosage, inducing branched-chain amino acids, and switching β-blocker medication from bisoprolol to carvedilol. Even though thoracentesis and drainages were performed twice for improvement of hypoxemia, right pleural effusion gradually decreased with the disappearance of dyspnea and she was discharged from our hospital on the 20th hospital day. We have been following her for 10 months and have found no evidence of pleural effusion. Although liver cirrhosis complicated with chylothorax is rare, several case reports have shown all patients with chylothorax caused by liver cirrhosis were transudative. It is assumed that portal hypertension by liver cirrhosis is associated with transudative chylothorax. This patient's case is complicated by insufficient ascites to be punctured. Other studies have reported that chylothorax occurs as a result of chylous ascites passing through the diaphragm in patients with liver cirrhosis;however, our case does not appear to fit the mechanism. Another study has proposed that portal hypertension increased lymph fluid production in the liver, this flow in the thoracic duct, and increased intrathoracic pressure resulting in the occurrence of chylothorax. We believe that switching β-blocker medication from bisoprolol to carvedilol is one of the reasons this patient's right chylothorax gradually decreased. According to one case study, a nonselective β-blocker improves chylothorax by lowering portal hypertension. As a result, a nonselective β-blocker such as carvedilol that improves portal hypertension may contribute to a reduction in cirrhotic chylothorax in this case. Bisoprolol, a selective β-blocker, has no effects on portal pressure and intrathoracic pressure. Our case report suggests that portal hypertension causes transudative chylothorax complicated by liver cirrhosis and that medication for portal hypertension improvement, such as a nonselective β-blocker, is one option for treatment.

[Possibilities and limitations of the use of beta-blockers in patients with cardiovascular disease and chronic obstructive pulmonary disease]

In medical literature, increasing attention is paid to comorbidities in patients with chronic obstructive pulmonary disease (COPD). In clinical practice, physicians often hesitate to prescribe beta-blockers (β1-adrenoblockers) to COPD patients. This article summarized new results of using beta-blockers in patients with COPD. According to reports, the selective β1-blocker treatment considerably increases the survival rate of patients with COPD and ischemic heart disease, particularly after myocardial infarction (MI), and with chronic heart failure (CHF). The benefit of administering selective β1-blockers to patients with CHF and/or a history of MI overweighs a potential risk related with the treatment even in patients with severe COPD. Convincing data in favor of the β1-blocker treatment in COPD patients without the above-mentioned comorbidities are not available. At present, the selective β1-blocker treatment is considered safe for patients with cardiovascular diseases and COPD. For this reason, selective β1-blockers, such as bisoprolol, metoprolol or nebivolol can be used in managing this patient cohort. Nonselective β1-blockers may induce bronchospasm and are not recommended for COPD patients. For the treatment with β-blockers with intrinsic sympathomimetic activity, the probability of bronchial obstruction in COPD patients is lower; however, drugs of this pharmaceutical group have not been compared with cardioselective beta-blockers. For safety reasons, the beta-blocker treatment should be started outside exacerbation of COPD and from a small dose. Careful monitoring is recommended for possible new symptoms, such as emergence/increase of shortness of breath, cough or changes in dosing of other drugs (for example, increased frequency of using short-acting bronchodilators).

[Patient age and CYP2D6*4/CYP2D6*3 genotype on maximal heart rate in patients after acute coronary syndrome treated with bisoprolol.]

We have analyzed influence of genetic variants CYP2D6*3 (2549delA) and CYP2D6*4 (1846G>A), as well as other factors on effects of bisoprolol in patients with acute coronary syndrome. The study included 97 patients with acute coronary syndrome. Mean age was 63±10 years; 60 men and 37 women. We have found association between carriage of CYP2D6*4 (1846G>A) and maximal heart rate at exertion (R-0,21; р<0,05). When the correction for potential confounders was made, age was the only significant predictor of maximal heart rate (β=0,6; SE=0,07; p<0,001). At the same time it was found that CYP2D6*4 was associated with more advanced age of the patients (r=0,2; p<0,05).

[Control of ventricular rate in permanent atrial fibrillation: cardio-protec-tion and tissue hemodynamics]

Objective To evaluate myocardial injury and tissue hemodynamics in elderly patients with permanent atrial fibrillation (AF) based on the achieved range of ventricular contraction rate (VCR).Materials and Methods This prospective, randomized, blind study included 75 patients aged ≥60 with permanent AF. All patients were prescribed bisoprolol as a VCR-reducing therapy. Patients were randomized to two groups according to the permuted-block design based on the range of resting VCR goal: group 1, 60-79 bpm (n=38) and group 2, 80-100 bpm (n=37). All patients also received perindopril and apixaban. Troponin I concentration was measured using the high-sensitivity assay (hsTn); parameters of tissue hemodynamics, including the mean blood flow velocity (Vm) and pulsatility index (PI), were measured using high-frequency ultrasound doppler flowmetry; echocardiographic indexes of left heart remodeling were recorded at baseline and after 6 month of VCR monitoring.Results Mean age of patients was 74±7 years. Medians [25th percentile; 75th percentile] of baseline hsTn concentrations were 10.2 [5.25; 21.2] ng / l in group 1 and 10.3 [5.4; 20.4] ng / ml in group 2 (p=0.91). 89.5 % of patients in group 1 and 100 % of patients in group 2 achieved the VCR range goal. At 6 month, resting VCRs were 70±4 bpm in group 1 (n=34) and 88±5 bpm in group 2 (n=37) (p1, p2&lt;0.001). According to echocardiographic data significant progression of myocardial remodeling was not observed. Concentrations of hsTn significantly decreased in both groups but the decrease was more pronounced in group 1, to 8.0 [4.13; 17.23; p1&lt;0.001] ng / l vs. 9.2 [4.8, 17.5] ng / l in group 2 (р1, p2&lt;0.001). A weak direct correlation was found between the VCR decrease and hsTn concentration (rs=0.44; p=0.009 in group 1, and rs=0.41; p=0.01 in group 2); regression coefficient was 0.78 at 95 % confidence interval (CI), from 0.21 to 1.3 (p=0.009) in group 1, and 0.14 at 95 % CI, from 0.04 to 0.24 (p=0.007) in group 2. Vm values were increased to 2.93±0.10 (p&lt;0.001) and 3.21±0.09 cm / sec (p&lt;0.001) and PIs were decreased to 1.42±0.03 conv. units (p&lt;0.01) and to 1.34±0.02 conv. units (p&lt;0.001) in groups 1 and 2, respectively.Conclusion The treatment aimed at VCR control in patients older than 60 with permanent AF was associated with a positive dynamics of myocardial injury (hsTn) and tissue hemodynamics indexes (Vm и РI). This indicates a possibility for using these indexes for further improvement of managing such patients.

[Not Available]

In this article we deal with the problem of low adherence of patients with ischemic heart disease (IHD) to drug therapy congruent to current recommendations including patients who underwent invasive interventions aimed at myocardial revascularization. Based on analysis of literature, we undertake an attempt to answer the question: which of components of this therapy patients with IHD are the least likely to continue taking? We also discuss approaches to the search for optimal composition of a combination preparation with fixed doses of an adreno-blocker and angiotensin converting enzyme inhibitor. Based on analysis of literature we undertook an attempt to answer a question: which of components of this therapy patients with IHD are least likely to continue taking. We also included in this article discussion of approaches to the search of optimal composition of a combination preparation containing fixed doses of a в-adrenoblocker and angiotensin converting enzyme inhibitor, as well as data on the role in the treatment of patients with IHD of bisoprolol and perindopril. Fixed doses of these agents have been included into a novel combination preparation.

Vigorous exercise mobilizes CD34+ hematopoietic stem cells to peripheral blood via the β2-adrenergic receptor

Acute dynamic exercise mobilizes CD34+ hematopoietic stem cells (HSCs) to the bloodstream, potentially serving as an economical adjuvant to boost the collection of HSCs from stem cell transplant donors. The mechanisms responsible for HSC mobilization with exercise are unknown but are likely due to hemodynamic perturbations, endogenous granulocyte-colony stimulating factor (G-CSF), and/or β2-adrenergic receptor (β2-AR) signaling. We characterized the temporal response of HSC mobilization and plasma G-CSF following exercise, and determined the impact of in vivo β-AR blockade on the exercise-induced mobilization of HSCs. Healthy runners (n = 15) completed, in balanced order, two single bouts of steady state treadmill running exercise at moderate (lasting 90-min) or vigorous (lasting 30-min) intensity. A separate cohort of healthy cyclists (n = 12) completed three 30-min cycling ergometer trials at vigorous intensity after ingesting: (i) 10 mg bisoprolol (β1-AR antagonist); (ii) 80 mg nadolol (β1 + β2-AR antagonist); or (iii) placebo, in balanced order with a double-blind design. Blood samples collected before, during (runners only), immediately after, and at several points during exercise recovery were used to determine circulating G-CSF levels (runners only) and enumerate CD34+ HSCs by flow cytometry (runners and cyclists). Steady state vigorous but not moderate intensity exercise mobilized HSCs, increasing the total blood CD34+ count by ∼4.15 ± 1.62 Δcells/µl (+202 ± 92%) compared to resting conditions. Plasma G-CSF increased in response to moderate but not vigorous exercise. Relative to placebo, nadolol and bisoprolol lowered exercising heart rate and blood pressure to comparable levels. The number of CD34+ HSCs increased with exercise after the placebo and bisoprolol trials, but not the nadolol trial, suggesting β2-AR signaling mediated the mobilization of CD34+ cells [Placebo: 2.10 ± 1.16 (207 ± 69.2%), Bisoprolol 1.66 ± 0.79 (+163 ± 29%), Nadolol: 0.68 ± 0.54 (+143 ± 36%) Δcells/µL]. We conclude that the mobilization of CD34+ HSCs with exercise is not dependent on circulating G-CSF and is likely due to the combined actions of β2-AR signaling and hemodynamic shear stress.

[Effects of L-carnitine and bisoprolol on endoplasmic reticulum stress-mediated myocardial injury after cardiopulmonary resuscitation in rats]

OBJECTIVE

To explore the effects of L-carnitine and bisoprolol on endoplasmic reticulum stress-mediated myocardial injury after cardiopulmonary resuscitation in rats.

METHODS

A total of 75 Sprague-Dawley rats were randomly divided into 5 groups of sham operation (sham); cardiopulmonary resuscitation (CR), L-carnitine (L), bisoprolol treatment (B) and L-carnitine and bisoprolol treatment (LB). Myocardial pathological changes were detected by hematoxylin and eosin, myocardial apoptosis by terminal deoxynucleotidyl transferase mediated dUTP nick and the expressions of key factors in endoplasmic reticulum (ER) by Western blot.

RESULTS

Compared with sham group, apoptosis and pathological lesions significantly increased in other groups (P < 0.05). And the levels of GRP78, CHOP and Caspase-12 were significantly higher (P < 0.05). The expression of ER factor protein and the degrees of myocardial injury in LB and B groups decreased compared with CR group. And LB group was the most obvious.

CONCLUSIONS

Combined use of levocarnitine and bisoprolol exerts protective effects on cardiopulmonary resuscitation in rats. And the mechanism may be related to an inhibition of ER stress.

Mechanisms of β-adrenergic receptor–mediated venodilation in humans

OBJECTIVES

Recent studies suggest that stimulation of beta-adrenergic receptors results in both endothelium-dependent and endothelium-independent venodilation, but results of former studies are inconsistent. This study was designed to elucidate the underlying mechanisms of isoproterenol (INN, isoprenaline)-induced venodilation by investigation of dorsal hand vein responses.

METHODS

In phenylephrine-constricted veins, isoproterenol (2-514 ng/min) was infused with and without oral pretreatment with 1 g acetylsalicylic acid (n = 7) or 5 mg of the selective beta(1)-adrenergic receptor antagonist bisoprolol (n = 7). In addition, isoproterenol was coinfused with the nitric oxide inhibitor N(G)-monomethyl-l-arginine (l-NMMA) (6.3 micromol/min [n = 6]), with selective blockers of calcium (Ca(++))-dependent potassium (K(+)) channels (tetraethylammonium, 300 microg/min [n = 6]) and adenosine triphosphate (ATP)-sensitive K(+) channels (glyburide [INN, glibenclamide], 20 microg/min [n = 6]) or with the cyclic guanosine monophosphate inhibitor methylene blue (13 microg/min [n = 6]). Finally, L-NMMA was coinfused with potassium chloride (20 mmol/L) to inhibit hyperpolarization (n = 6).

RESULTS

Isoproterenol induced dose-dependent venodilation to 67.4% +/- 6.8%. Oral pretreatment with bisoprolol (P =.340) or acetylsalicylic acid (P =.760) did not affect isoproterenol-induced venodilation. Coinfusion of isoproterenol and L-NMMA relaxed the veins to the same extent as in the presence of isoproterenol alone. Neither inhibition of ATP-sensitive K(+) channels (P =.196) nor blockade of Ca(++)-dependent K(+) channels (P =.640) modulated isoproterenol-induced venodilation. In contrast, methylene blue reduced the maximum response to isoproterenol by about one third (68.5% +/- 4.3% versus 41.7% +/- 5.5%, P =.001). Infusion of L-NMMA alone raised vein size to 38.8% +/- 6.5%, yielding an L-NMMA-sensitive increase of 20% (P =.001), which was antagonized by coinfusion of potassium chloride to 17.1% +/- 6.7% (P =.02).

CONCLUSIONS

Isoproterenol dilates human hand veins exclusively via beta(2)-adrenergic receptors without involvement of endothelium-derived epoprostenol. Although a contribution of endothelium-derived nitric oxide appears unlikely, the venodilating effect of L-NMMA could have obscured the nitric oxide component of isoproterenol. beta(2)-Adrenergic receptor-mediated dilation is mediated in part by cyclic guanosine monophosphate-dependent mechanisms, whereas ATP- and Ca(++)-dependent K(+) channels are not involved, excluding a significant contribution of smooth muscle cell hyperpolarization. In addition, high concentrations of the nitric oxide synthase blocker L-NMMA dilate human hand veins via activation of endothelium-derived hyperpolarizing factors.

Efficacy of domestic bisoprolol,enalapril and nifedipine retard in mild to moderate hypertension: a randomized double-blind multicenter clinical trial in China

OBJECTIVE

To compare the efficacy and tolerability of bisoprolol, enalapril and nifedipine retard in the treatment of mild to moderate essential hypertension.

METHODS

This is a randomized, double-blind, multicenter clinical trial. 331 patients with mild to moderate hypertension in the army troop were randomly allocated to receive domestic bisoprolol ( n =110,5 mg/d),enalapril ( n =111,10 mg/d) and nifedipine retard ( n =110,20 mg/day). Total duration of active drug treatment was 4 weeks.

RESULTS

The total efficacy rates of domestic bisoprolol, enalapril and nifedipine retard were 80.0%, 82.0% and 81.8% respectively P > 0.05 . The incidences of adverse events were 4.5%, 8.1% and 19.1% (P < 0.01 ) in patients of bisoloprol, enalapril and nifedipine retard groups respectively. The adverse effects were mild in all the three groups.

CONCLUSIONS

Domestic bisoprolol, enalapril and nifedipine retard are effective and well-tolerated in patients with mild to moderate essential hypertension. The occurrence of adverse effects were least in the bisoprolol group and most in the nifedipine retard group.

Comparison of bisoprolol and diazepam in the treatment of cardiac neurosis

In order to compare the beta blockers bisoprolol and diazepam in the treatment of cardiac neurosis, 40 patients (16 males and 24 females, mean age: 39 +/- 11 years) were examined in a double-blind, crossover study. Following a 4-week placebo period, patients were randomized to receive either bisoprolol 10 mg daily or diazepam 5 mg twice daily for 4 weeks. After a second 4-week washout period on placebo, patients were switched to the alternative regimen for a further 4 weeks. At the end of the placebo periods and during each phase of treatment, the following parameters were evaluated: somatic symptoms by self-assessment questionnaire, anxiety state by Hamilton rating scale, reaction time to both acoustic and visual stimuli, blood pressure, and heart rate. Both treatments were effective in reducing somatic symptoms of cardiac neurosis, but bisoprolol was significantly more effective than diazepam (p less than 0.01). On the contrary, diazepam was superior to bisoprolol in improving the Hamilton scale related to psychic symptoms. Only diazepam prolonged reaction times. Both treatments were well tolerated; however, 12 patients complained of drowsiness and nine of sedation under diazepam. In conclusion, bisoprolol appeared to be as effective as diazepam in the treatment of cardiac neurosis, but with better effects on somatic symptoms and without affecting patients' psychomotor performance.

Effects of Acute Febrile Infectious Diseases on the Oral Pharmacokinetics and Effects of Nitrendipine Enantiomers and of Bisoprolol

In 2 longitudinal studies with 10 patients each, the stereoselective pharmacokinetics of nitrendipine and the pharmacokinetics of racemic (rac) bisoprolol (both 20mg orally) were investigated during acute febrile infectious diseases and at least 6 weeks later in the healthy state. The area under the plasma concentration-time curve (AUC) and peak plasma concentration (Cmax) of rac-nitrendipine were increased in the infectious state by 89% [95% confidence interval (CI): 24 to 187%] and 95% (95% CI: 22 to 209%), respectively. Similar increases were observed for both S- and R-nitrendipine. Nitrendipine exhibited stereoselective pharmacokinetics in both the healthy state and the infectious state, but the mean ratios of S:R AUC values [healthy: 1.79 (95% CI: 1.36 to 2.11); infectious: 1.87 (95% CI: 1.62 to 2.11)] were not different. The elimination half-life, protein binding and haemodynamic effects of nitrendipine also did not differ between the infectious and the healthy state. The mechanism for the disease effects may be related to suppression of hepatic cytochrome P450 activity by mediators of inflammatory reactions. On the other hand, none of the pharmacokinetic parameters, including nonrenal clearance, of rac-bisoprolol was changed during febrile infectious disease, indicating specificity in the effects of acute febrile disease on oxidative drug metabolism.

Comparison of casual, ambulatory and self-measured blood pressure in a study of nitrendipine vs bisoprolol

In a double-blind, placebo-controlled study the antihypertensive efficacy and tolerability of a single morning dose of either 10 mg bisoprolol (n = 26) or 20 mg nitrendipine (n = 27) were investigated. Blood pressure was measured by three techniques: (1) Casual blood pressure 24 h after the dose; (2) ambulatory 24-h whole-day monitoring; and (3) self-recorded blood pressure in the morning 24 h after the dose (6-8 a.m.) and in the evening (6-8 p.m.). After 4 weeks of therapy bisoprolol had produced a highly significant reduction in blood pressure as assessed by causal, ambulatory day- and night-time monitoring, and self-measured morning and evening readings. Bisoprolol was significantly more effective than nitrendipine, which did not induce a significant reduction in the ambulatory night-time recordings. Whole-day ambulatory blood pressure profiles showed an antihypertensive effect of bisoprolol throughout the entire 24-h period. 24-h blood pressure curves after nitrendipine demonstrated a markedly shorter duration of action, with no reduction in early morning blood pressure. Adverse effects and tolerability of the two drugs were comparable. The average changes in systolic and diastolic blood pressure after bisoprolol and nitrendipine in 2-h periods of ambulatory monitoring (6-8 a.m. and 6-8 p.m.) and self-measured blood pressure (6-8 a.m. and 6-8 p.m.) showed a good agreement between ambulatory and self-measured blood pressure determinations with no significant difference between the methods. The results show that 24 h antihypertensive efficacy was more pronounced for bisoprolol than for nitrendipine at the doses studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the safety and efficacy of bisoprolol versus atenolol in stable exercise-induced angina pectoris: a Multicenter International Randomized Study of Angina Pectoris (MIRSA)

Bisoprolol 10 mg and atenolol 100 mg once daily were compared regarding efficacy and safety in stable effort angina in a 12-week, multicenter, double-blind, randomized, parallel-group study. Efficacy was evaluated with angina pectoris diaries and bicycle exercise tests. Spontaneously mentioned complaints and side effects were recorded at each visit. In 11 centers, 147 patients completed the study; 76 received bisoprolol 10 mg, and 71 received atenolol 100 mg. After 12 weeks, weekly anginal attack rate was reduced significantly (p less than 0.05) with bisoprolol (5 +/- 0.5 to 2 +/- 0.6) and with atenolol (4 +/- 0.4 to 1 +/- 0.2). Peak exercise capacity (in W x min) increased significantly (p less than 0.05) with bisoprolol (772 +/- 47 to 878 +/- 52) and with atenolol (891 +/- 46 to 986 +/- 53). Rate pressure product (RPP) at peak exercise (in beats/min x mm Hg) decreased significantly (p less than 0.05) with both bisoprolol (25,003 +/- 692 to 20,116 +/- 637) and atenolol (26,544 +/- 557 to 21,603 +/- 576) (all values are mean +/- SE). The differences between the groups were not statistically significant. There were no significant differences regarding nature and incidence of adverse events between the groups. Thus, bisoprolol 10 mg once daily and atenolol 100 mg once daily are equipotent in their effects on stable effort angina. Both regimens were comparable with respect to incidence and nature of side effects.

Results of a double-blind study versus metoprolol]

AIMS

Comparison of bisoprolol, a beta-1 selective beta blocker with no intrinsic sympathomimetic activity (ISA) and metoprolol, which numerous studies have shown to be an effective migraine prophylactic.

STUDY DESIGN

Multicentric, cross-over study.

PATIENTS

125 patients suffering at least from 3 attacks of classic or common migraine a month for at least two years.

TREATMENT

Bisoprolol 5 mg given once a day, or metoprolol 50 mg given twice a day, for two periods of 12 weeks.

RESULTS

125 patients were admitted to the 4-week run-in phase. A comparison of the main target: frequency of migraine attacks was thus carried out in 78 patients (f. = 63, m. = 15). Both substances reduced the average frequency of migraine per 28-day period by about 50%. There was no statistically significant difference between the two beta-blockers (p greater than 0.05).

CONCLUSIONS

The results of the study show that 5 mg of bisoprolol and 100 mg of metoprolol a day have comparable efficacy for migraine prophylaxis, and show comparable tolerability.

An evaluation of self-measured blood pressure in a study with a calcium-channel antagonist versus a beta-blocker

In recent years self-measurement of blood pressure at home has gained increasing importance but there have been only a few studies comparing casual, ambulatory, and self-measured blood pressure determinations during a single clinical trial. We therefore compared treatment-induced blood pressure-reductions in a double-blind, placebo-controlled, parallel study design with a single morning dose of either 10 mg bisoprolol (n = 26) or 20 mg nitrendipine (n = 27) with casual blood pressure readings in the morning before the dose, ambulatory 24-h monitoring, and self-recorded measurements in the morning before the dose and in the evening. Mean reductions for systolic and diastolic blood pressure after 4 weeks of therapy were significantly greater for bisoprolol than for nitrendipine. The treatment-induced blood pressure reductions were most pronounced as assessed by casual readings but showed good agreement between casual, ambulatory, and self-measured blood pressure for group comparisons. In some patients, however, marked individual differences between the three methods were observed. Correlation coefficients between ambulatory and self-measured blood pressure were 0.4 for systolic blood pressure (P less than .05) and 0.6 for diastolic blood pressure (P less than .0005). Under the conditions of this parallel study design and the usual statistical risks, a difference of 5 mm Hg in diastolic blood pressure can be detected in 118 patients at the clinic, in 70 patients if ambulatory blood pressure is used, or in 56 patients if self-measured blood pressure is used. In conclusion, bisoprolol was more effective over 24 h than nitrendipine at the doses studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of celiprolol, a cardioselective beta-blocker, on respiratory function in asthmatic patients

The aim of this study was to compare the pulmonary effects of a single dose of celiprolol 400 mg, versus bisoprolol 20 mg and the combination of celiprolol 400 mg plus propranolol 40 mg versus placebo plus propranolol 40 mg. We conducted a double-blind randomized cross-over study in 10 stable asthmatic patients (mean age +/- SD 31 +/- 7 yrs) with forced expiratory volume in one second (FEV1): 2.5 +/- 0.7 l. A three-day washout period preceded each treatment period. Measurements of respiratory function were done before treatment and after 90, 120 and 180 min. There was a significant increase of FEV1 (+12%) and forced vital capacity (FVC) (+8%) after celiprolol (p less than 0.05) and a decrease of FEV1 (-9%) after propranolol. Concerning the combination, celiprolol inhibits the bronchoconstrictor effects of propranolol. We conclude that celiprolol has bronchosparing properties in asthmatic patients, and even improves some of the ventilatory parameters.

Nitrendipine in the therapeutic management of elderly hypertensive patients: results of a multicenter trial. Andalousian Hypertension Group

Two hundred forty-seven [142 women (57.49%)] elderly patients with essential hypertension (diastolic blood pressure between 95 and 114 mm Hg) and an average age of 67.4 +/- 6 years were included in an open multicenter ambulatory trial. One hundred thirty-seven had some kind of associated disease. After a 15-day washout period, the patients began nitrendipine therapy (10 mg o.d.). After 1 month, the dose was increased to 20 mg o.d. in patients with diastolic blood pressure (DPB) greater than or equal to 95 mm Hg, and thereafter 5 and 10 mg o.d. of bisoprolol was added to the maximal dose of nitrendipine (20 mg o.d.) in the case of patients with DBP greater than or equal to 95 mm Hg at the end of the second and third months, respectively. At the end of the 6-month follow-up period, the systolic and diastolic pressures had dropped -35 and -21 mm Hg, respectively, without any change in heart rate or Quetelet index. In 210 patients (84.9%), blood pressure control was achieved: 26 (10.5%) with 10 mg of nitrendipine, 149 (60.3%) with 20 mg of nitrendipine, and 35 (14.1%) by adding bisoprolol. The lipid profile, glucose, potassium, uric acid, or creatinine did not change negatively. Sixty-six (26.72%) patients reported clinical side effects, although these were mild; only 15 (6.07%) patients were excluded because of side effects. Nitrendipine has been shown to have a high therapeutic efficacy and biochemical tolerance for first-line treatment of elderly patients with mild-to-moderate essential hypertension with or without associated diseases.

Discrepancies between inotropic responses and beta-adrenoceptor characteristics after global ischemia in isolated hearts

The influence of global ischemia on cardiac beta-adrenoceptors was studied in rat and guinea pig Langendorff hearts (LH), both by functional and binding experiments using the specific beta-adrenoceptor ligand (-)-[125I]-iodocyanopindolol. Neither ischemia (30 or 60 min) nor postischemic reperfusion caused any change in beta-adrenoceptor density, affinity or in the beta 1/beta 2 ratio in LH of normal rats or in LH of rats pretreated with reserpine or 6-hydroxydopamine (6-OHDA), or in guinea pig LH, whereas perfusion of rat LH with 10(-5) M isoprenaline (15 min) caused the expected decrease in beta-adrenoceptor density. After ischemia, isoprenaline was no longer able to influence beta-adrenoceptor density, suggesting that the internalization mechanism is impaired. In functional studies, perfusion of the rat LH with 10(-5) M isoprenaline (15 min) shifted the concentration-response curve for isoprenaline to the right. Thirty-minute global ischemia virtually abolished the inotropic but not the chronotropic response to isoprenaline. Ischemia did not impair the inotropic response to ouabain or to calcium, indicating that the contractile apparatus itself was still largely intact. Our results suggest that the contractile failure after ischemia is not caused by a decrease in beta-adrenoceptor density or by a defect in the contractile apparatus but by an impaired second-messenger system.

Pharmacokinetics of intravenous bisoprolol in obese and non-obese volunteers

The pharmacokinetics of a single i.v. dose of dl-bisoprolol 0.16 mg.kg-1 ideal body weight has been studied in 8 obese women (mean weight 91 kg; 161% of ideal body weight) and 8 non-obese women (51 kg; 94% of ideal body weight). Compared to the controls, the obese subjects showed an increase in the total apparent volume of distribution (Vz) (182 vs 1351) and a decrease in Vz per kg body weight (2 vs 2.71.kg-1). There was a negative correlation between Vz l.kg-1 and the percentage of ideal body weight (r = -0.672). Total body clearance was increased, but t1/2 and renal clearance was unchanged. It is concluded that tissue diffusion of bisoprolol in obese subjects is limited, despite its lipophilicity, possibly because of alteration in the blood flow to adipose tissue produced by bisoprolol.

Oral pharmacokinetics of bisoprolol in resting and exercising healthy volunteers

The effects of exercise on bisoprolol oral pharmacokinetics were studied in eight healthy male volunteers in an open, randomized, three-period, crossover trial. Oral bisoprolol (20 mg) was given either at rest during 24 h or with iterative stress tests before and 2.5, 5, 10, and 24 h after dosing. Exercise tests were repeated on a third placebo period. Bisoprolol was assayed in plasma and urines, and plasma catecholamines were measured before and after stress tests, Cmax, Tmax, elimination t1/2, and renal clearance of bisoprolol were not significantly modified by exercise. AUC0-infinity significantly decreased by 7.5% (p less than 0.05) with stress test resulting in an increase in apparent oral clearance. The beta-blocking effect peaked at 2.5 h, lasted greater than 24 h, and was related to plasma levels. The exercise-induced increase in plasma norepinephrine levels was significantly augmented with bisoprolol. These results suggest that repeated exercise tests exerted only limited effects on the oral pharmacokinetics of bisoprolol.

Effect of bisoprolol on blood pressure and arterial hemodynamics in systemic hypertension

Blood pressure, heart rate, common carotid and brachial arterial hemodynamics using pulsed Doppler flowmetry and pulse wave velocity determinations were evaluated using a double-blind crossover design versus placebo in 14 patients with sustained essential hypertension treated by the selective beta 1 blocking agent bisoprolol. Blood pressure and heart rate significantly decreased after bisoprolol, whereas no significant change occurred in the diameter, the blood flow and in the vascular resistance of the carotid and brachial circulations. Pulse wave velocity significantly decreased in the brachioradial and the carotid femoral areas. The decrease in the latter was -1.6 +/- 0.8 m/s with bisoprolol and -0.06 +/- 0.80 m/s with placebo (p = 0.001). Brachial artery compliance significantly increased from 117 +/- 49 to 205 +/- 84 cm4 x dynes-1 x 10(9) (p = 0.001), indicating that the antihypertensive effect of beta 1 blockade is associated with an improvement in the viscoelastic properties of the brachial artery wall.

Hemodynamic evaluation of bisoprolol after coronary artery surgery in patients with altered left ventricular function

Bisoprolol is a new cardioselective beta1 adrenergic blocking agent without intrinsic sympathomimetic activity but with minimal effects on myocardial contractility. Bisoprolol was compared to propranolol in 24 patients after cardiac surgery for coronary artery bypass graft (CABG). Each patient had been treated preoperatively with beta-blocking agents and had a cineangiographic left ventricular ejection fraction between 35% and 55%. Patients were randomized to receive orally either 10 mg of propranolol three times a day or 5 mg of bisoprolol once a day. Both drugs resulted in a significant and similar decrease in heart rate. This was associated with significant decreases in cardiac index, stroke index, and thermodilution right ventricular ejection fraction 6 hours after administration of propranolol, but not after bisoprolol. Systolic function measured by Doppler techniques significantly increased in the 10 postoperative days in patients under bisoprolol but not significantly after propranolol. Each drug was well tolerated during the 10 postoperative days, and the recovery was uneventful in each patient. These results indicate that in patients with altered systolic function after CABG, bisoprolol is susceptible to reduce heart rate with less cardiovascular alteration than propranolol.

Cardiovascular effect of low-dose epinephrine infusions in relation to the extent of preoperative beta-adrenoceptor blockade

The relationship between the extent of preoperative beta-adrenoceptor blockade and the hemodynamic properties of epinephrine was investigated in patients scheduled for elective myocardial revascularization during the immediate preoperative period under steady-state hemodynamic and anesthetic conditions. Twenty patients had been treated with beta-adrenoceptor blocking drugs for at least 3 weeks before the study; 11 unblocked patients served as control group. The extent of clinical beta-adrenoceptor blockade was quantified using the isoproterenol sensitivity test. The dose of isoproterenol required to increase heart rate by 25 beats per min was defined as the chronotropic dose 25 (CD25), representing the degree of beta-adrenoceptor blockade. Geometric mean CD25 per 70 kg was 3.0 micrograms in the control group and 21.8 micrograms in the patients receiving beta-adrenoceptor blocking drugs. The authors found a significant inverse relationship between CD25 values and changes in cardiac index in response to three epinephrine infusion rates (0.01, 0.02, and 0.04 micrograms.kg-1.min-1), the correlation coefficients being -0.71, -0.81, and -0.86, respectively. Compared to unblocked patients, almost no change, or even a decrease, of the cardiac index was observed at greater degrees of clinical beta-adrenoceptor blockade, particularly in patients receiving nonselective blockers. Moreover, there was a significant linear correlation (r = 0.76-0.86) between CD25 values and the effects of epinephrine on systemic vascular resistance index (SVRI); i.e., SVRI significantly decreased in control patients but markedly increased in patients with high degrees of preoperative beta-adrenoceptor blockade. This unmasked vasoconstrictive response to low doses of epinephrine was observed despite the fact that the majority of our patients had received cardioselective adrenergic blocking drugs.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effects of bisoprolol and atenolol on glucose metabolism in hypertensive patients with non-insulin-dependent diabetes mellitus]

Effects of bisoprolol and atenolol on glucose metabolism in hypertensive patients NIDDM. The aim of the study was to compare the antihypertensive efficacy and the effects on glucose metabolism of a new beta 1-selective beta-blocker with high beta 1 selectivity, bisoprolol and atenolol in 12 hypertensive patients (WHO classes I e II) suffering from untreated not insulin-dependent diabetes mellitus (NIDDM). According to a cross-over design after a placebo run-in period of 4 weeks, the patients were randomly allocated to receive bisoprolol 10 mg o.d. or atenolol 100 mg o.d. for 4 weeks, with a four-week wash-out period between the two active treatments. In basal condition and after each therapy an intravenous glucose tolerance test (i.v. GTT, 20 g) was performed, with evaluation of serum glucose and insulin at 0, 15, 30, 60, 90, 120 minutes and glycosuria during the test. At the same time blood pressure, heart rate (supine, upright), ECG, laboratory tests were assessed and subjective tolerability was evaluated. The glucose and insulin responses to the i.v. GTT did not significantly change to basal condition. Similarly glycosuria did not show significative increment during the test with both beta-blocking therapies. Blood pressure and heart rate values were significantly reduced (p less than 0.001) after bisoprolol and atenolol treatment. During the study no side effects were reported and laboratory tests and ECG remained substantially unchanged. These data confirm the antihypertensive efficacy of bisoprolol and atenolol and demonstrate the absence of important effects of these drugs on glucose metabolism in hypertensive patients with NIDDM.

[Treatment of acute phase of myocardial infarction with injectable bisoprolol with oral versus]

The early treatment of acute myocardial infarction with beta-blockers represents a major advance in the management of this condition which was proved in a large serie of international studies including a total of about 30,000 patients, and in recent overviews. As a whole such treatment reduces total mortality by 13 to 14% during the first week (p less than .02) in the treated group compared with the controls. The mortality reduction appears most marked in the first two days, about 25%, after early intravenous infusion. Data on non fatal reinfarction in hospital suggest that early treatment reduces this risk by about 19% (p less than .01). Furthermore data on all patients suffering deaths, non fatal arrest and non fatal reinfarction indicate a 16% reduction in the risk of suffering one of these major events (p less than .001) and provide strong evidence of the beneficial effect of this class. Bisoprolol (Detensiel) is a high beta 1-selective beta-adrenoceptor blocking agent without intrinsic sympathomimetric activity and local anaesthetic activity. Its pharmacokinetic profile appears extremely favourable with a plasma elimination half-life of about 10 h and a balanced clearance: bisoprolol is inactivated by liver metabolism (about 50%) and excreted unchanged in the urine (about 50%). Two pilot open studies were performed up to now with IV bisoprolol in acute myocardial infarction (MI). The first trial (n = 37) confirms the clinical and ECG safety of the administered dose regimen: repeated IV infusion of 1 mg up to a cumulative maximum dose of 5 mg and subsequent oral treatment with 10 mg once daily (o.d.).(ABSTRACT TRUNCATED AT 250 WORDS)

A dose-ranging study to evaluate the beta 1-adrenoceptor selectivity of bisoprolol

A dose-ranging study was performed to compare the beta 1-adrenoceptor selectivity of bisoprolol with that of atenolol and nadolol. Seven normal subjects (mean age 26 y) were given single oral doses of bisoprolol 5 mg (B5), 10 mg (B10), 20 mg (B20); atenolol 50 mg (A50), 100 mg (A100); nadolol 40 mg (N40); and placebo (PL), in a single blind randomised cross-over design. Beta 2-adrenoceptor responses were assessed by attenuation of finger tremor and cardiovascular responses to graded isoprenaline infusions. Dose-response curves were constructed, and doses of isoprenaline required to increase finger tremor by 100% (IT100), heart rate by 25 beats/min (IH25), SBP by 25 mmHg (IS25), cardiac output by 35% (IC35), and decrease DBP by 10 mmHg (ID10), after each treatment were calculated. These indices were compared with placebo response and expressed as dose-ratios. Exercise heart rate (EHR) was used to assess beta 1-adrenoceptor blockade. There were dose-related increases in plasma concentrations of bisoprolol and atenolol. Reduction of EHR was significantly less with B5 (16.8%) in comparison with all other treatments: B10 21.9%, B20 23.1%; A50 22.5%, A100 22.6%; N40 22.9%. There were small but significant reductions in isoprenaline-induced tachycardia with bisoprolol and atenolol, although mean dose-ratios were considerably less in comparison with N40 (IH25 dose-ratios): B5 2.55, B10 3.18, B20 3.93, A50 2.91, A100 4.89, N40 17.23. There were similar patterns for the other isoprenaline responses. These results show that conventional doses of bisoprolol (10 mg) and atenolol (50 mg) produced equal antagonism of beta 1 and beta 2-adrenoceptors, and therefore possess equal degrees of beta 1-adrenoceptor selectivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of beta-1 selectivity of bisoprolol and atenolol by means of their influence on the lipolytic response to an infusion of terbutaline

We have investigated the beta-1 selectivity of a new beta-blocker, Bisoprolol, by comparing its effect on lipolysis induced by intravenous terbutaline infusion with that of Atenolol. At a dose of 5 mg, Bisoprolol had virtually no beta-2 blocking activity as measured by free fatty acid (FFA) release during terbutaline infusion. At a dose of 10 mg, Bisoprolol had a small but statistically insignificant effect on FFA release similar to 50 mg Atenolol. At a dose of 20 mg, Bisoprolol had significant beta-2 blocking activity. At lower doses, therefore, Bisoprolol is a very selective beta-blocker.

High performance liquid chromatographic measurement of bisoprolol in plasma

A simple high performance liquid chromatographic method has been devised for the measurement of bisoprolol in plasma or serum. The sample (200 microL) is vortex mixed for 30 s with 2 M Tris solution (50 microL), aqueous internal standard (benzimidazole, 2.0 mg/L, 50 microL) and methyl t-butyl ether (200 microL). After centrifugation (9950 x g, 2 min), a portion of the resulting extract is analysed on a microparticulate (5 microns) silica column using 1 mM camphorsulphonic acid in methanol as the mobile phase. Detection is by fluorescence at an excitation wavelength of 215 nM. The lower limit of accurate measurement for the assay is 10 micrograms/L (CV% = 8.9, n = 9) with a lower limit of detection of 5 micrograms/L. There is minimal interference from either commonly prescribed drugs or endogenous compounds.