A comparison of the tolerability of the direct renin inhibitor aliskiren and lisinopril in patients with severe hypertension

Patients with severe hypertension (>180/110 mm Hg) require large blood pressure (BP) reductions to reach recommended treatment goals (<140/90 mm Hg) and usually require combination therapy to do so. This 8-week, multicenter, randomized, double-blind, parallel-group study compared the tolerability and antihypertensive efficacy of the novel direct renin inhibitor aliskiren with the angiotensin converting enzyme inhibitor lisinopril in patients with severe hypertension (mean sitting diastolic blood pressure (msDBP)>or=105 mm Hg and <120 mm Hg). In all, 183 patients were randomized (2:1) to aliskiren 150 mg (n=125) or lisinopril 20 mg (n=58) with dose titration (to aliskiren 300 mg or lisinopril 40 mg) and subsequent addition of hydrochlorothiazide (HCTZ) if additional BP control was required. Aliskiren-based treatment (ALI) was similar to lisinopril-based treatment (LIS) with respect to the proportion of patients reporting an adverse event (AE; ALI 32.8%; LIS 29.3%) or discontinuing treatment due to AEs (ALI 3.2%; LIS 3.4%). The most frequently reported AEs in both groups were headache, nasopharyngitis and dizziness. At end point, ALI showed similar mean reductions from baseline to LIS in msDBP (ALI -18.5 mm Hg vs LIS -20.1 mm Hg; mean treatment difference 1.7 mm Hg (95% confidence interval (CI) -1.0, 4.4)) and mean sitting systolic blood pressure (ALI -20.0 mm Hg vs LIS -22.3 mm Hg; mean treatment difference 2.8 mm Hg (95% CI -1.7, 7.4)). Responder rates (msDBP<90 mm Hg and/or reduction from baseline>or=10 mm Hg) were 81.5% with ALI and 87.9% with LIS. Approximately half of patients required the addition of HCTZ to achieve BP control (ALI 53.6%; LIS 44.8%). In conclusion, ALI alone, or in combination with HCTZ, exhibits similar tolerability and antihypertensive efficacy to LIS alone, or in combination with HCTZ, in patients with severe hypertension.

Effect of individualizing starting doses of a statin according to baseline LDL-cholesterol levels on achieving cholesterol targets: The Achieve Cholesterol Targets Fast with Atorvastatin Stratified Titration (ACTFAST) study

AIMS

To investigate whether selecting the starting dose of atorvastatin according to baseline and target (<2.6 mmol/L) LDL-cholesterol (LDL-C) values would allow high-risk subjects to achieve target LDL-C concentration within 12 weeks, with the initial dose or a single uptitration.

METHODS AND RESULTS

Twelve-week, prospective, open-label trial that enrolled 2117 high-risk subjects (statin-free [SF] or statin-treated [ST]). Subjects with LDL-C >2.6 mmol/L (100mg/dL) but <or=5.7 mmol/L (220 mg/dL) were assigned a starting dose of atorvastatin (10, 20, 40 or 80 mg/day) based on LDL-C and status of statin use at baseline, with a single uptitration at 6 weeks, if required. There was no washout for ST subjects. At study end, 80% of SF (82%, 82%, 83% and 72% with 10, 20, 40 and 80 mg, respectively) and 59% of ST (60%, 61% and 51% with 20, 40 and 80 mg, respectively) subjects reached LDL-C target. In the ST group, an additional 21-41% reduction in LDL-C was observed over the statin used at baseline. Atorvastatin was well tolerated.

CONCLUSION

This study confirms that individualizing the starting dose of atorvastatin according to baseline and target LDL-C values (i.e. the required LDL-C reduction), allows a large majority of high-risk subjects to achieve target safely, within 12 weeks, with the initial dose or with a single titration.

Bilateral axillobrachial and external carotid artery manifestation of giant cell arteritis: important role of color duplex ultrasonography in the diagnosis

A 76-year-old man was admitted to our hospital with vertigo. Previously he had been extensively examined because of an increased erythrocyte sedimentation rate without any clinical symptoms. Physical examination revealed 60 mmHg blood pressure difference between the two arms. Color duplex ultrasound examination revealed bilateral extreme narrowing of the external carotid and axillobrachial artery with a dark, hypo-echoic halo around the lumen. This condition was recognized as a specific sign for giant cell arteritis (GCA), described originally in cases of temporal arteritis. The diagnosis was confirmed by biopsy of the temporal artery. In contrast to the typical cranial form of GCA -- our patient showed an unusual, bilateral large-vessel manifestation. The diagnosis was based on ultrasound images rather than on symptoms that characterize the well-known temporal form. This observation emphasizes the role of color duplex ultrasonography in the diagnosis and follow-up of GCA.

Effective control of hypertension: a project of the Hungarian society of hypertension, baseline data

The aim of the project is to assess the quality and improve the preventive and curative practices at the primary care level in Hungary. A total of 50 general practitionaires were selected on a voluntary basis in Budapest, Hungary, and from them, 30 were randomized to the intervention (I) group and 20 to the reference (R) group. The members in the I group have been trained for the official hypertension guideline and their everyday work is monitored. Those in the R group have only been monitored to measure the efficacy of the training. In all, 10% from the known hypertensive persons (N=10,799) and 5% of the remaining (nonhypertensive) patients (N=60,341) were selected randomly from the GP's computer files and invited for screening investigation performed by trained medical students. They measured the blood pressure of patients, assessed the cardiovascular risk status and the quality of education of patients by standardized questionnaires. In total, 4083 patients were invited, but only 39.2% attended the screening visit. The prevalence of undetected hypertension was 34.6%. This prevalence was significantly higher in the older (>60 years: 46.8%) than in the younger (<50 years: 20.8%, P<0.0001) age group and it was higher in men (41.5%) than in women (30.1%, P<0.001). The proportion of H patients on drug treatment was 85.3% and the frequency of patients under effective blood pressure control (eg<140/90 mmHg) was 27.8%. Counselling to patients for a healthier lifestyle (exercise, smoking, alcohol consumption, diet) was very rare. In conclusion, our data represent the primary care of Budapest and may not be relevant to the whole country. As a consequence of this study, education of primary care physicians and patients is a must for further improvement of hypertension care.

An Open-Label Study Investigating the Efficacy and Safety of 12–96 Weeks of Telmisartan Treatment in Patients with Hypertension

This open-label, multicentre, multinational trial evaluated the efficacy and safety of telmisartan used alone or as add-on therapy in 2121 adults with mild-to-moderate essential hypertension. Patients received telmisartan 40-80 mg once daily for 12 weeks and could participate in the study for up to 96 weeks, or until a marketed supply of telmisartan became available. Mean change from baseline in mean seated trough diastolic blood pressure (DBP) after 12 weeks' treatment, the primary endpoint, was −11.8 mmHg in the intent-to-treat population. The corresponding mean change in mean seated trough systolic blood pressure (SBP) was −20.2 mmHg. Both changes were statistically significant. Mean DBP and SBP reductions were apparent from week 4 and maintained throughout the treatment period. Telmisartan was well tolerated; the most common adverse events were headache (6%) and dizziness (3%), and 10% of adverse events were considered drug-related. In conclusion, telmisartan is an effective and well-tolerated drug when used as monotherapy or add-on treatment in this broad population of patients.

Bupropion SR for smoking cessation in smokers with cardiovascular disease: a multicentre, randomised study

AIMS

To investigate the safety and efficacy of bupropion sustained release (bupropion SR) in promoting abstinence from smoking in subjects with cardiovascular disease (CVD).

METHODS

Six hundred twenty-nine subjects with CVD who smoked >/=10 cigarettes/day were randomised in a double-blind, multicentre study to receive bupropion SR (150 mg twice daily) or placebo for 7 weeks, with a follow-up of 52 weeks. Primary efficacy endpoint: continuous abstinence from smoking from weeks 4 to 7. Secondary endpoints: continuous abstinence (weeks 4-12, 4-26 and 4-52) and weekly point prevalence abstinence. All participants received brief motivational support. Safety was evaluated throughout the study.

RESULTS

Continuous smoking abstinence rates from weeks 4 to 7 were significantly higher in subjects receiving bupropion SR compared with placebo (43 vs. 19%, odds ratio [OR]=3.27, 95% confidence interval [CI] 2.24-4.84; P<0.001). Continuous abstinence rates from weeks 4 to 26 and 4 to 52 continued to be more than double for bupropion SR compared with placebo (27 vs. 11%; 22 vs. 9%, P<0.001). Weekly point prevalence abstinence was significantly higher for participants who received bupropion SR compared with placebo at weeks 3, 7, 26 and 52 (P<0.001). In both groups, there were no clinically significant changes in blood pressure and heart rate throughout the treatment phase. Overall, 6% of the participants (n=36) discontinued study medication due to an adverse event (bupropion SR, n=17; placebo, n=19).

CONCLUSIONS

After 7 weeks of bupropion SR treatment, more than twice as many smokers with CVD had quit smoking at 1 year compared with placebo. The safety profile of bupropion SR was similar to that previously observed in general smoking populations.

Study on COgnition and Prognosis in the Elderly (SCOPE): baseline characteristics

The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multi-centre, prospective, randomized, double-blind, parallel-group study. The primary objective of SCOPE is to assess the effect of the angiotensin II type 1 (AT1) receptor blocker, candesartan cilexetil 8-16 mg once daily, on major cardiovascular events in elderly patients (70-89 years of age) with mild hypertension (DBP 90-99 and/or SBP 160-179 mmHg). The secondary objectives of the study are to test the hypothesis that antihypertensive therapy can prevent cognitive decline (as measured by the Mini Mental State Examination, MMSE) and dementia, and to assess the effect of therapy on total mortality, myocardial infarction (MI), stroke, renal function, and hospitalization. A total of 4964 patients from 15 participating countries were recruited during the randomization phase of SCOPE, exceeding the target population of 4000. The mean age of the patients at enrolment was 76 years, the ratio of male to female patients was approximately 1:2, and 52% of patients were already being treated with an antihypertensive agent at enrolment. The majority of patients (88%) were educated to at least primary school level. At randomization, mean sitting blood pressure values were SBP 166 mmHg and DBP 90 mmHg, and the mean MMSE score was 28. Previous cardiovascular disease in the study population included myocardial infarction (4%), stroke (4%) and atrial fibrillation (4%). Men, more often than women, had a history of previous MI, stroke and atrial fibrillation. A greater percentage of men were smokers (13% vs 6% in women) and had attended university (11% vs 3% of women). Of the randomized patients, 21% were 80 years of age. In this age group smoking was less common (4% vs 10% for 70-79-year-olds) and fewer had attended university (4% vs 7% for 70-79-year-olds). The incidence of MI was similar in both age groups. However, stroke and atrial fibrillation had occurred approximately twice as frequently in the older patients. The patients' mean age at baseline was similar in the participating countries, and most countries showed the approximate 1:2 ratio for male to female patients. There was also little inter-country variation in terms of mean SBP, DBP or MMSE score. However, there was considerable regional variation in the percentage of patients on therapy prior to enrolment.

The efficacy and tolerability of losartan versus atenolol in patients with isolated systolic hypertension. Losartan ISH Investigators Group

OBJECTIVE

To compare the efficacy and tolerability of angiotensin II (Ang II) antagonist losartan and the beta-blocker atenolol in the treatment of patients with isolated systolic hypertension (ISH) after 16 weeks of treatment.

METHODS

A double-blind, randomized, multi-country study was carried out in 273 patients with ISH. Patients with a sitting systolic blood pressure (SiSBP) of 160-205 mmHg, and a sitting diastolic blood pressure (SiDBP) < 90 mmHg at screening and at placebo baseline were subjected to a 4-week placebo period and then randomly grouped to receive 50 mg losartan or 50 mg atenolol once daily for 16 weeks. At 8 and 12 weeks, patients not controlled (SiDBP > or = 160 mmHg) were given additional treatment of 12.5 mg hydrochlorothiazide (HCTZ) once daily.

RESULTS

Similar significant reductions in SiSBPs (mean +/- SD) were obtained with 50 mg losartan and 50 mg atenolol, from 173.7 +/- 10.3 and 173.5 +/- 10.7 mmHg at baseline to 149.0 +/- 15.5 and 148.2 +/- 15.3 mmHg after 16 weeks of losartan or atenolol treatment respectively. Sixty-seven percent of the losartan-treated and 64% of the atenolol-treated patients remained on monotherapy throughout the study. Only 1.5% of the losartan-treated patients withdrew because of a clinical adverse event (CAE) compared with 7.2% in the atenolol-treatment group (P= 0.035). Drug-related CAEs were observed significantly more frequently with atenolol than with losartan treatment (20.3 versus 10.4%; P = 0.029).

CONCLUSION

It is concluded that 50 mg losartan and 50 mg atenolol produced comparable reductions in SiSBP in patients with ISH but losartan was better tolerated. This is the first demonstration of the therapeutic value of selective Ang II receptor blockade with losartan in the treatment of ISH.

Study on COgnition and Prognosis in the Elderly (SCOPE)

The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multicentre, prospective, randomized, double-blind, parallel-group study designed to compare the effects of candesartan cilexetil and placebo in elderly patients with mild hypertension. The primary objective of the study is to assess the effect of candesartan cilexetil on major cardiovascular events. The secondary objectives of the study are to assess the effect of candesartan cilexetil on cognitive function and on total mortality, cardiovascular mortality, myocardial infarction, stroke, renal function, hospitalization, quality of life and health economics. Male and female patients aged between 70 and 89 years, with a sitting systolic blood pressure (SBP) of 160-179 mmHg and/or diastolic blood pressure (DBP) of 90-99 mmHg, and a Mini-Mental State Examination (MMSE) score of 24 or above, are eligible for the study. The overall target study population is 4000 patients, at least 1000 of whom are also to be assessed for quality of life and health economics data. After an open run-in period lasting 1-3 months, during which patients are assessed for eligibility and those who are already on antihypertensive therapy at enrolment are switched to hydrochlorothiazide 12.5 mg o.d., patients are randomized to receive either candesartan cilexetil 8 mg once daily (o.d.) or matching placebo o.d. At subsequent study visits, if SBP remains >160 mmHg, or has decreased by <10 mmHg since the randomization visit, or DBP is >85 mmHg, study treatment is doubled to candesartan cilexetil 16 mg o.d. or two placebo tablets o.d. Recruitment was completed in January 1999. At that time 4964 patients had been randomized. All randomized patients will be followed for an additional 2 years. If the event rate is lower than anticipated, the follow-up will be prolonged.

Imidazoline receptors: from discovery to antihypertensive therapy (facts and doubts)

The hypothesis and indirect evidence of imidazoline receptors has been promoted since some 15 years ago and it gave a substantial impetus for research in this field, resulting in a better understanding of neuronal and cardiovascular regulatory processes. The nomenclature of the imidazoline receptors has been accepted by international forums but no direct proof for the existence of these receptors has been published. Authors summarise the most important available data, including facts and doubts as far as the discovery, characterisation, and function of imidazoline receptors and their subtypes, the differences between imidazoline receptors and alpha-2 adrenoceptors, and also on their participation in regulatory processes.

[Role of food interaction pharmacokinetic studies in drug development. Food interaction studies of theophylline and nifedipine retard and buspirone tablets]

Due to several mechanism, meals may modify the pharmacokinetics of drug products, thereby eliciting to clinically significant food interaction. Food interactions with the drug substance and with the drug formulation should be distinguished. Food interaction of different drug products containing the same active ingredient can be various depending on the pharmaceutical formulation technology. Particularly, in the case of modified release products, the food/formulation interaction can play an important role in the development of food interaction. Well known example, that bioavailability of theophylline can be influenced in different way (either increased, decreased or unchanged) by concomitant intake of food in the case of different sustained release products. The role and methods of food interaction studies in the different kinds of drug development (new chemical entity, modified release products, generics) are reviewed. Prediction of food effect response on the basis of the physicochemical and pharmacokinetic characteristics of the drug molecule or formulations is discussed. The results of three food interaction studies carried out the products of EGIS Pharmaceuticals Ltd. are also reviewed. The pharmacokinetic parameters of theophyllin 400 mg retard tablet were practically the same in both fasting condition and administration after consumption of a high fat containing standard breakfast. The ingestion of a high fat containing breakfast, increased the AUC of nifedipine from 259.0 +/- 101.2 ng h/ml to 326.7 +/- 122.5 ng h/ml and Cmax from 34.5 +/- 15.9 ng/ml to 74.3 +/- 23.9 ng/ml in case of nifedipine 20 mg retard tablet, in agreement with the data of literature. The statistical evaluation indicated significant differences between the pharmacokinetic parameters in the case of two administrations (before and after meal). The effect of a high fat containing breakfast for a generic version of buspiron 10 mg tablet and the bioequivalence after food consumption were studied in a single-dose, three-way (test and reference products administered after consumption of standard breakfast, as well as test product in fasting condition), cross-over, food effect bioequivalence study. According to the results, the test product--which, in a former study proved to be bioequivalent with the reference product in fasting state--is bioequivalent with the reference product under feeding conditions and the food intake influenced the pharmacokinetics of the test tablets.

[Captopril treatment of hypertension]

After the brief description of the most important hypertensive pathophysiological processes (renin, angiotensins) which are closely related to angiotensin converting enzyme (ACE) inhibitors as well as to the mechanisms of action of captopril, author summarizes the essential clinical findings from the international and Hungarian literature. A short guideline for the administration of captopril to hypertensive patients is also given.

Human bioequivalence study of a new nifedipine containing retard filmtablet after single and repeated administration

A clinical pharmacokinetic bioequivalence study with two retard filmtablet preparations, both containing 20 mg of nifedipine (CAS 219829-25-4) was carried out. The investigated test preparation was Cordaflex 20 mg retard filmtablet. The pharmacokinetic parameters were determined after single and repeated administration in 15 and 16 healthy male volunteers, respectively, in open, randomised studies of cross-over design. Plasma levels of nifedipine were determined by HPLC with electrochemical detection using a robotic sample preparation technique. Statistical comparison of the pharmacokinetic parameters (AUC0-infinity, AUCss, tau tmax, Cmax, Css,min, Css,av, MRT, etc.) calculated from plasma concentration-time curves by ANOVAlog, confidence interval, Schuirman's, Westlake's, Anderson's and Wilcoxon's tests, furthermore the comparison of the clinical results did not show any significant difference between the two preparations. It is concluded that the two preparations are bioequivalent after repeated administration.

[Effect of fluvastatin on serum lipid levels in essential hypertension]

The efficacy and safety of the HMG-CoA reductase fluvastatin was investigated in a multicenter, open label clinical therapeutic trial in the treatment of hypercholesterinaemia in hypertensive patients (WHO I-II.). 49 patients were involved, 6 patients were dropped out because of th lack of compliance, 43 patients were investigated (mean age: 57.6 +/- 9.4 years, mean blood pressure: 146 +/- 16/88+/- g mmHg (systolic/diastolic). The antihypertensive treatment was unchanged during the study. An 8 weeks low-lipid diet was started if the fasting total cholesterol (TC) level was equal or higher than 6.5 mM/L and the triglyceride level was lower than 4.6 mM/L. After the dietary period fluvastatin treatment was started (20 mg o.d.), if the level of LDL-C was higher than 4,1 mM/L. Blood pressure, heart rate, TC, HDL-C (HDL2-C, HDL3-C), apoA1, apoB, TG were measured at the 4th, 8th, 12th weeks of treatment. LDL-C was calculated with Fridewald equation. The daily dose of fluvastatin was increased to 40 mg, if LDL-C level was higher than 3.5 mM/L after 4 weeks of treatment. 36 patients completed the study (Group B). 7 patients were dropped out at the end of the dietary period, because of the significant decrease of TC and LDL-C levels (Group A). In Group B fluvastatin significantly reduced the level of TC (from 7.22 +/- 0.88 to 5.99 +/- 0.98 mM/L), of LDL-C (from 5.13 +/- 0.71 to 3.95 +/- 0.88 mM/L), and the level of ApoB (from 0.97 +/- 0.26 to 0.85 +/- 0.15 mM/L), but did not influence significantly the level of HDL-C, ApoA1 and TG. The diastolic blood pressure decreased significantly during the dietary period, while after beginning the fluvastatin treatment the decrease of the systolic blood pressure became significant. There was no change in the heart rate. Only minor side effects were observed in 3 patients (dysuria, constipation, lack of appetite). Fluvastatin proved to be an effective and well-tolerated drug in the treatment of hypercholesterinaemia in hypertensive patients.

[Comparative human pharmacokinetic studies of 20 mg nifedipine-containing Cordaflex and Adalat film coated retared tablets]

Comparative pharmacokinetic studies have been carried out with two 20 mg nifedipine active substance-containing retard film coated tablets, Cordaflex produced by EGIS Pharmaceuticals Co., Ltd. and Adalat of Bayer AG. The pharmacokinetic parameters and the relative bioavailability were determined in 15 and 16 healthy male volunteers, respectively after single and repeated administration in open, randomized cross over study. The plasma concentration of nifedipine was determined by HPLC-ED method, using laboratory robot for automated sample preparation. On the basis of graphical and statistical comparison of the pharmacokinetic parameters (AUC0-infinity, AUCss,0-tau, tmax, Cmax, Css,min, Css,av, MRT, etc.) calculated from the time-plasma concentration curve, moreover on the basis of clinical results, there was no significant difference between the two preparations. In conclusion, the relative bioavailability of Cordaflex and Adalat 20 mg retard tablets did not show significant difference after single and repeated administration.

Hungarian Isradipine Study (HIS): long-term (3-year) effects on blood pressure and plasma lipids

These are the preliminary data of an open multicenter trial of antihypertensive treatment with isradipine as monotherapy (dose, 4.55 +/- 0.56 mg twice daily; n = 11) or isradipine (7.5 +/- 0.63 mg twice daily) in combination with bopindolol (1.16 +/- 0.12 mg once daily; n = 30) administered for 3 years to patients with essential hypertension (WHO classification I or II). Blood pressure was significantly decreased in both treatment groups and there was no indication of resistance to therapy. Plasma levels of total cholesterol and triglycerides were decreased by the end of the second year of treatment, and there was a tendency toward increase in plasma levels of high-density lipoprotein cholesterol (HDL2 or HDL3). The atherogenic index (ratio between total cholesterol and HDL2 plus HDL3) was also decreased. Blood glucose levels remained unchanged in both normoglycemic patients and those with non-insulin-dependent diabetes mellitus (NIDDM) during 3 years of therapy. It is concluded that isradipine is safe and effective when administered long-term in the treatment of hypertensive patients with either hyperlipidemia or NIDDM.

Antihypertensive effect of the calcium antagonist isradipine and lipid profile

The hypothesis that plasma lipids may modulate the antihypertensive effect of the calcium antagonist isradipine was tested in 85 patients who had essential hypertension. Significant linear correlations were found between the antihypertensive effect of isradipine and plasma levels of total cholesterol and high-density lipoprotein (HDL2 or HDL3) in normotriglyceridemic (n = 63), but not in hypertriglyceridemic (n = 22), patients. From this, we conclude that normal levels of plasma lipids may modulate the function of calcium channels and their interaction with calcium antagonists.

[The "white coat effect" in hypertensive patients]

The "white coat effect" has been investigated by non-invasive automatic blood pressure monitoring in patients with hypertension, defined by casual blood pressure readings. A significant "white coat effect" has been demonstrated in 30 (32%) of the 93 patients: the average values were 17/9 mmHg and 6 beat/min, the highest values were 37/29 mmHg and 13 beat/min. The examination has been repeated after 24 hours in 11 cases and the phenomenon was reproducible. The "white coat effect" did not disappear even when the changes were compared to the averages of three subsequent automatic blood pressure measurements. There were significantly more women, than men among the "white coat" positive patients. However, no difference was found in age, occupation and the known duration of hypertension. Neither was any correlation between the "white coat effect" and the blood pressure reaction to mental arithmetic test. It is emphasized that the casual readings can significantly overestimate the blood pressure. This finding must be considered especially in the diagnosis of borderline hypertension.

[The anti-lipidemic effect of Minipress]

Prazosin (Minipress) monotherapy was given to 152 patients with essential hypertension for one year in a multi-center study involving 13 hospitals and university clinics. In three centers serum levels of total cholesterol, HDL-cholesterol and triglycerides were also determined in 32 patients with hypertension and hyper/dys-lipoproteinemia. As a consequence of Minipress monotherapy significant decreases were found in serum level of cholesterol (after three months and also after one year), triglycerides (after one year), while the serum concentration of HDL-cholesterol increased. Atherogenic index (a ratio of total cholesterol over HDL-cholesterol) was significantly decreased by Minipress. As new data showing a causative correlation between hypertension and hyperlipoproteinemia were published in the literature authors, on the basis of their results, suggest to determine lipid profile in every patient with hypertension. They regard Minipress as the first line drug in young patients with "familial dyslipidemic hypertension". When choosing an antihypertensive drug metabolic side effects should be taken into consideration.

[Blood pressure lowering effect of nifedipine in smokers and non-smokers]

The authors summarized the relationships between the cardiovascular diseases and smoking. In their retrospective study they studied the acute antihypertensive effect of nifedipine in patients with essential hypertension who were smokers and nonsmokers. They suggest that the antihypertensive effect of nifedipine did not decrease in smokers. Therefore the nifedipine can be the first choice in the antihypertensive therapy in smokers with essential hypertension.

Retrospective analysis of clinical data of normotensive and hypertensive pregnant women and their newborns

The medical history of 256 hypertensive and 263 normotensive pregnant women was analysed retrospectively. There was a negative correlation (P less than 0.01) between the maximal pretreatment diastolic blood pressure and the birth weight of newborns in the hypertensive group. The prevalence of a hypertensive family history, pyelonephritis, proteinuria, delivery by Caesarean section, fetal asphyxia during delivery and death of the newborn during delivery was significantly higher in the hypertensive group than in the normotensive one. The gestational age at delivery was shorter and the birth weight of the newborn was lower in the hypertensive women than in the normotensive women.

Nifedipine-prazosin interaction in patients with essential hypertension

In an acute, double-blind, crossover study on 12 patients with essential hypertension, the interaction between nifedipine and prazosin was investigated in the supine position. The effectiveness of the combination of the two active drugs was greater than the combination of either of the drugs plus placebo. The effect of nifedipine was not modified by prazosin pretreatment; however, the effect of prazosin was partly inhibited, i.e., delayed, by nifedipine pretreatment. Therefore, giving prazosin as a first drug and nifedipine as the second drug seems to be a better approach than the reverse.

[Diagnostic and therapeutic significance of automatic circadian monitoring in hypertension]

A noninvasive, fully automatic blood pressure monitoring system has been developed to make the measurement of blood pressure more reliable and to help individualizing anti-hypertensive therapy. The authors draw attention to the importance of the circadian blood pressure variability and the "white coat hypertension" phenomenon. The error due to overlooking the changes in circadian blood pressure and to the "white coat" effect could be avoided with automatic blood pressure monitoring. Their system consists of two subunits: the Nippon Colin (BP 203 MII) blood pressure monitor, which has been fitted to the Commodore 64 computer by their own interface and data transfer program. Data analyzing and graphic displaying programs have also been developed by them. The diagnostic and therapeutic importance of blood pressure monitoring are demonstrated with representative cases of patients with essential, renoparenchymal and renovascular hypertension. The perspectives of this method in clinical pharmacology are also illustrated and discussed.

Presynaptic alpha 2-adrenoceptors exclusively sensitive to agonists of phenylethylamine structure on the sympathetic nerves of the human gall bladder artery

The influence of alpha 2-adrenoceptor agonists and antagonists on the release of noradrenaline was studied in human gall bladder (cystic) artery preparations, in which transmitter stores were labelled with [3H]noradrenaline. The preparations were stimulated at 2 Hz for 3 min (360 shocks each of 1 ms duration two times (S1 and S2)). Both the L-noradrenaline and alpha-methylnoradrenaline (10(-6) M) significantly reduced (S2/S1 = 0.27 +/- 0.05; 0.43 +/- 0.04, respectively), whilst clonidine, xylazine and guanfacine at 10(-6) M failed to affect the stimulation evoked release of [3H]noradrenaline. Yohimbine (10(-6) M), CH-38083, which is a new, selective alpha 2-adrenoceptor antagonist (10(-7) M) and prazosin (10(-6) M) enhanced the evoked release of radioactivity, where S2/S1 were 2.50 +/- 0.19; 2.99 +/- 0.32; 1.48 +/- 0.05, respectively. Administering the alpha 2-antagonists and prazosin together, we were unable to demonstrate an additive effect. Yohimbine and CH-38083 prevented, while prazosin reduced, the inhibitory effects of L-noradrenaline or alpha-methylnoradrenaline on the release of radioactivity. Our results suggest that one type of presynaptic alpha 2-adrenoceptor modulates the release of noradrenaline evoked by electrical stimulation of the human cystic artery. This receptor is sensitive to alpha 2-adrenoceptor agonists which have a phenylethylamine structure, but is insensitive to imidazolines and guanfacine.

Metoclopramide decreases baroreflex sensitivity in patients with essential hypertension

The effect of metoclopramide (10 mg, iv.) or physiological saline on the exercise-induced (standardized bicycle ergometry) increase in blood pressure and heart rate of patients with essential hypertension was investigated in a double blind, randomized, self controlled study. Metoclopramide had no effect on the exercise-induced increase in blood pressure but significantly enhanced the tachycardia due to ergometry after 4-6 min exercise. The mean slope of linear regression lines calculated from the systolic blood pressure and the corresponding heart rate measured before and during (at 1,2,3,4,5 min) exercise after metoclopramide was significantly steeper than after physiological saline (1.1 +/- 0.12 vs 0.79 +/- 0.09; mean +/- SEM), indicating the decrease in baroreflex sensitivity after metoclopramide. On the basis of results the possible role of endogenous dopaminergic mechanisms in suppressing some components of pressor effect of physical exercise can be hypothesized.

Prazosin partly blocks clonidine-induced hypotension in patients with essential hypertension

Prazosin has been reported to reduce the hypotensive and/or bradycardic effect of clonidine in various animal models. Investigations in humans have given conflicting conclusions about the effectiveness of the combination of clonidine and prazosin. In patients with essential hypertension prazosin significantly reduced the hypotensive effect of intravenous clonidine, but it failed to affect the clonidine-induced bradycardia. This finding means that the combination of prazosin and clonidine is inappropriate in antihypertensive therapy.

Thyrotropin releasing hormone and naloxone attenuate the antihypertensive action of central alpha 2-adrenoceptor stimulation through different mechanisms

In various forms of shock, TRH is equivalent to naloxone in reversing the hypotension and improving the survival rate. The present findings indicate that in spontaneously hypertensive rats (SHR), TRH has another naloxone-like effect in antagonizing the antihypertensive response to clonidine and alpha-methyldopa. When given during the hypotensive response to alpha-methyldopa, both naloxone and TRH produce a pressor response. While this effect of naloxone is blocked by prazosin, the effect of TRH is not influenced by prazosin or hexamethonium but is inhibited by a vasopressin pressor antagonist. This suggests that the pressor response to naloxone is mediated by the sympathetic nervous system, whereas the similar action of TRH is independent of sympatho-adrenomedullary functions and it is mediated by vasopressin.

Effects of clonidine and guanfacine in essential hypertension

Daily doses of 0.3 mg clonidine and 3 mg guanfacine were equiactive in decreasing blood pressure and heart rate in 17 subjects with essential hypertension. Clonidine decreased cardiac output and guanfacine decreased total peripheral resistance, while clonidine had no effect on stroke volume but guanfacine increased it. Both clonidine and guanfacine decreased plasma renin activity. Naloxone, 0.4 mg iv, reversed the antihypertensive effect of clonidine but was ineffective even at higher doses (1.6 mg iv) when subjects were treated with placebo or guanfacine. It is suggested that the hemodynamic differences between the two centrally acting alpha 2-adrenoceptor agonist antihypertensive drugs may at least in part result from the involvement of opioid mechanisms only in the action of clonidine.

Beta-endorphin contributes to the antihypertensive effect of clonidine in a subset of patients with essential hypertension

Naloxone [0.4 mg iv.] increased blood pressure and heart rate of 13 clonidine-treated [0.3 mg per os for 3 days] patients with essential hypertension [reacting group] while it has no such effect in 11 clonidine-treated patients [non-reacting gr.] Clonidine increased plasma beta-endorphin concentration of the reacting patients by 17.53 +/- 1.68 pM/1 and in the non-reacting ones by 5.91 +/- 0.88 pM/1. Significant linear correlation was found between the clonidine-induced increase in plasma beta-endorphin level and the naloxone-induced change in mean blood pressure [r = 0.9572, n:24, p less than 0.001]. In another group of 8 patients clonidine [0.15 mg iv.] decreased mean blood pressure but naloxone, 30 min after the clonidine injection, did not reverse the clonidine hypotension. We suggest that beta-endorphin, released by chr. clonidine therapy, contributes to the anti-hypertensive effect only in the reacting group.

Reversal by naloxone of the antihypertensive action of clonidine: involvement of the sympathetic nervous system

The effects of clonidine, naloxone, and their combination on arterial blood pressure (BP), heart rate (HR), and hemodynamic and biochemical parameters were examined in 29 patients with essential hypertension. Treatment for 3 days with 0.3 mg/day clonidine reduced BP and HR, and these effects were quickly reversed by a single injection of 0.4 mg iv naloxone in 17 of the patients (responders), but not in the remaining 12 (nonresponders). Responders had higher control values for cardiac output, stroke index, plasma renin activity (PRA), and plasma epinephrine levels than did nonresponders. Basal BP was similar in the two groups, but clonidine decreased BP, PRA, and plasma epinephrine more in responders than in nonresponders. Naloxone given during placebo treatment had no significant effects. During clonidine treatment naloxone increased BP, HR, total peripheral resistance, PRA, and plasma epinephrine and norepinephrine, and decreased stroke volume in responders, whereas in nonresponders its only effect was a small increase in HR. It is concluded that in a subset of hyperadrenergic, hypertensive patients the antihypertensive effect of clonidine involves a naloxone-reversible inhibition of central sympathetic outflow, probably mediated by the release of an endogenous opioid.