Effects of pharmacogenetics on pharmacokinetics and toxicity of doxorubicin in Egyptian breast cancer patients

This study investigates the impact of single nucleotide polymorphisms in genes (SLC22A16 and CBR1) involved in the pharmacokinetics and toxicity of doxorubicin (DOX) in Egyptian female patients with breast cancer.Patients administered DOX (60 mg/m2) for 4 cycles every 3 weeks. The peak DOX plasma concentration was measured using a validated chromatographic method. The genotyping for the selected SNPs, SLC22A16 T > C (rs714368), and CBR1 C > T (rs20572), was performed by RT-PCR. Patients were monitored for hematological and cardiac toxicities.The variant carriers of CBR1 C > T (rs20572) exhibited significantly higher DOX concentration, but no significant association to DOX-induced hematological toxicity. On the other hand, SLC22A16 T > C (rs714368) had no significant influence on DOX plasma concentration, but was significantly correlated with lower risk of neutropenia (OR 0.31, 95% CI 0.12-0.75, p = 0.01) and leukopoenia (OR 0.18, 95% CI 0.07-0.5, p = 0.001). DOX-related cardiotoxicity was correlated with the cumulative dose of DOX (R = 0.238, p = 0.017), but not with any of the two examined SNPs.Genetic polymorphisms in SLC22A16 and CBR1 may explain the inter-individual variations in DOX pharmacokinetics and toxicity. Using pharmacogenetic testing is important to customise drug therapy for cancer patients treated with anthracyclines.

The effects of genetic polymorphism on toxicity and pharmacokinetics of methotrexate in Egyptian adult patients with leukaemia or lymphoma

Polymorphisms in genes coding folate-metabolising enzymes might alter the pharmacokinetics and sensitivity for methotrexate "MTX".The aim of the study aimed to investigate the influence of MTHFR C677T, DHFR19 Ins/del, GGH -401 C > T, and MTR A2756G polymorphisms on MTX toxicity and pharmacokinetics in Egyptian patients with Acute lymphoblastic leukaemia (ALL) or Non-Hodgkin lymphoma (NHL).Fifty adult Egyptian patients with ALL and NHL, treated with high dose MTX, were prospectively enrolled in the study. Clinical and biochemical data was collected objectively from medical records after each cycle of MTX. Plasma concentrations of MTX were measured after 72 h of initiation of infusion. Genotyping was done with a PCR-ARMS and PCR-RFLP assays.The MTHFR C677T T variants significantly increased the risk of leukopoenia, whereas the genotype MTHFR 677 C > T TT significantly associated with lymphocytopenia, thrombocytopenia, and anaemia. The genotype GGH-401 TT was significantly correlated with anaemia. Plasma MTX level was significantly higher in patients with MTR A2756G G variants.MTHFR polymorphism played the main role in MTX toxicities. The pharmacokinetics of MTX was affected by MTR polymorphism. GGH mutation was mainly concerned with anaemia. Pharmacogenetic testing are recommended to optimise MTX therapy.

Clinical and Laboratory Factors Related to Seizure and Serotonin Toxicity in Tramadol Intoxication: An Egyptian Study

BACKGROUND AND OBJECTIVES

Tramadol is a centrally acting analgesic with a lower risk of addiction compared to opioids. Tramadol overdose is becoming a health crisis in Egypt and is associated with serious and severe adverse effects. This study aims to identify clinical and laboratory findings associated with tramadol-induced seizure and serotonin toxicity in adult Egyptian patients with tramadol overdose.

METHODS

This prospective study included adult patients admitted for tramadol overdose with or without symptoms of seizure or serotonin toxicity. Basic demographic information, clinical symptoms, laboratory measurements, and plasma tramadol concentrations were collected.

RESULTS

A total of 71 patients (79% males) were included in the study. Seizure occurred in 38% of the subjects and was prevalent in male patients with metabolic acidosis or high tramadol concentrations. Serotonin toxicity occurred in 41% of the subjects and was prevalent in patients with hyperthermia, high pulse rate, and high tramadol levels.

CONCLUSION

Seizure and serotonin toxicity are severe adverse effects of tramadol overdose that occur in high frequency among young Egyptians. High tramadol concentrations in plasma seem to play a key role in prevalence of seizure and serotonin syndrome in tramadol-intoxicated adult Egyptians.

Pharmacokinetics of ampicillin during venovenous extracorporeal membrane oxygenation: A case report

The presence of extracorporeal membrane oxygenation (ECMO) in addition to underlying critical illness can affect the pharmacokinetics and pharmacodynamics of drugs that are often required to treat this patient population. While ampicillin is the preferred agent for the treatment of susceptible Enterococcus faecalis infections, there are no in vivo pharmacokinetic studies regarding ampicillin dosing in patients receiving ECMO. This case report consists of two patients on venovenous ECMO with E. faecalis bloodstream infections in which ampicillin serum concentrations were measured. Pharmacokinetic parameters were calculated using a one compartment open model. Ampicillin trough levels were 5.87 and 39.2 mg/L for patients A and B, respectively. Based on these results, ampicillin concentrations were found to be above the minimum inhibitory concentration (MIC) for 100% of the dosing interval. The findings of this case report demonstrate that therapeutic concentrations of ampicillin can be obtained in patients on ECMO and therapeutic drug monitoring can be utilized to ensure adequate serum concentrations are achieved.

Changes in dietary habits during Covid-19 lockdown in Egypt: the Egyptian COVIDiet study

PURPOSE

COVID-19 lockdown changed social habits and lifestyle, including dietary habits, of people worldwide. However, limited information is available about these changes in Egypt. This cross-sectional study investigates the effects of COVID-19 lockdown on dietary habits among the Egyptian populations.

METHODS

An online questionnaire, based on sociodemographic data and dietary adherence in accordance with the validated PREDIMED MedDiet Adherence Screener (MEDAS), was used all over the Egyptian governorates. The dietary changes were statistically evaluated for significance in relation to age, gender, body mass index (BMI), education level and governorates.

RESULTS

A total of 1010 participants (76% aged below 36 years, 77% female, 22% obese, and 62% university-level education) answered the questionnaire. Respondents ≤ 20 years had a significant increase in weight and consumption of carbonated beverages, commercial pastries, fried and fast food. Egyptians > 50 years old had a significant decrease in physical activity. Underweight people (less than 3% of participants) increased their fast food intake with a prominent rise in weight. However, obese people increased cooking frequency and increased eating times with a decrease in physical activity. Male participants reported increased intake of carbonated beverages and fast food, while female participants increased the intake of homemade pastries with a significant decrease in physical activity. Approximately 50% of participants with postgraduate education reported decreased intake of fast food and carbonated beverages as well as decreased body weight. Residents of Cairo showed a significant increase in vegetable intake, and fried food intake with a decrease in seafood consumption. Participants from the Delta region had a significant increase in pastries intake.

CONCLUSION

The findings of this study explored the need for increasing awareness about healthy lifestyle in future lockdown periods.

Linezolid-associated serotonin toxicity: a systematic review

PURPOSE

This systematic review aims to evaluate the existing evidence associating linezolid to serotonin toxicity when used as monotherapy or when co-administered with other serotonergic agents.

METHODS

A systematic literature search using PubMed (till March 2023), IDWeek meetings (2003-2023), the European Congress of Clinical Microbiology and Infectious Disease Annual Meetings (2001-2023), and the American College of Clinical Pharmacy (1999-2023) identified studies and abstracts related to linezolid and serotonin toxicity.

RESULTS

A total of 84 studies were included. The data collected in retrospective/observational studies compared the incidence of serotonin toxicity with linezolid monotherapy at 0.0050% and linezolid combination therapy at 0.0134%. All cases which discontinued linezolid and serotonergic agent/s at signs and symptoms of toxicity found symptom resolution; 75% of cases reported serotonin toxicity resolution within 24-48 h after discontinuation.

CONCLUSION

Linezolid therapy when optimal should not be deferred due to the risk of serotonin syndrome. The data collected reveals a low prevalence of serotonin toxicity in both linezolid monotherapy and linezolid concurrent with other serotonergic agents.

Natural Products; from the Laboratory to Clinical Practice

It has been such a great honor to serve as the Guest Editor for this Special Issue, “Exploration on Pharmacokinetics and Pharmacodynamics of Natural Molecules: Current Status and Future Perspectives” [...]

Factors Impacting Job Satisfaction among Pharmacists in the Arab World: A Qualitative Study

Purpose

This study was undertaken to investigate in-depth the factors impacting job satisfaction among pharmacists in the Arab world and the challenges they encounter in their career path. The outcome of this study should help the local policymakers to take corrective actions to improve pharmacist's satisfaction and therefore enhance quality of patient care.

Method

This qualitative study collected responses of pharmacists from 12 Arab countries, as part of a large quantitative survey. Participants added comments to an optional open-ended question regarding work satisfaction. The Qualtrics Survey Software was used to collect the responses. The survey was distributed from March to May 2021 through multiple online channels for filling. The responses collected were analysed to develop themes. An inductive constructivist approach was used for the conceptual thematic analysis as the methodological orientation.

Results

A total of 110 responses/comments were received from the study participants. The two largest practice settings of the participants were from hospitals (44.5%) and community pharmacies (28.2%). Almost 40% of responses came from pharmacists practising in Qatar (21.8%) and UAE (18.1%). The survey data demonstrated several reasons impacting job satisfaction among pharmacists practising in the Arab countries. Underestimation of the pharmacists' role, low salaries, lack of motivation and excessive workload were reported as major contributors to job dissatisfaction. On the other hand, professional commitment and the culture of the work setting were the major contributors to job satisfaction.

Conclusions

The study provides valuable insights into the aspects concerning pharmacists' satisfaction in the Arab world. Policymakers and other stakeholders need to act upon aspects of pharmacists' job satisfaction and dissatisfaction to ensure potentially better working environment and patient outcomes.

Catechin Reduces Blood Pressure in Spontaneously Hypertensive Rats through Modulation of Arachidonic Acid Metabolism

(1) Background: hypertension affects approximately half of the adults in the United States (roughly 116 million). The cytochrome P450 (CYP)-mediated metabolism of arachidonic acid (AA) in the kidney has been found to play a major role in the pathogenesis of hypertension. This study examines the anti-hypertensive effect of the natural polyphenolic compound catechin (CAT) and investigates if it impacts the metabolism of AA in the kidney in comparison to captopril (CAP): a commonly used antihypertensive drug. (2) Methods: spontaneously hypertensive rats (SHR) were randomly divided into five groups. The treatment groups were administered CAT in drinking water at doses of 10 and 50 mg/kg. A positive control group received CAP at a dose of 10 mg/kg in the drinking water, and one group received both CAP and CAT at doses of 10 mg/kg and 50 mg/kg, respectively. Blood pressure was monitored weekly for five weeks. The activity of the two major enzymes involved in AA metabolism in the kidney, namely CYP4A and soluble epoxide hydrolase (sEH), were analyzed. (3) Results: CAP monotherapy was found to reduce blood pressure compared to the control untreated rats but did not demonstrate any effect on AA metabolism. Low- and high-dose CAT resisted the rise in blood pressure observed in the untreated SHR and significantly lowered blood pressure compared to the control group, respectively. Only rats treated with high CAT doses demonstrated significant inhibition of CYP4A and sEH enzyme activities. The coadministration of CAP and a high dose of CAT resulted in more pronounced blood pressure-lowering effects, but no more significant effects on AA metabolism were found compared to a high dose of CAT alone. (4) Conclusion: the modulation of AA metabolism in the kidney contributes, at least partially, to the blood pressure-lowering effect of CAT in SHR rats.

Exploring job satisfaction among pharmacy professionals in the Arab world: a multi-country study

Objectives

The study objectives were to (1) describe the characteristics of the pharmacy professionals and (2) explore the association between job satisfaction and factors, such as work control, work stress, workload and organization and professional commitments.

Methods

This study was a cross-sectional design. The survey items were mainly adapted from the US National Pharmacist Workforce Survey. An electronic (Qualtrics) questionnaire was posted on pharmacist social media in several Arab countries. The survey link was posted from 22 March 2021 to 1 May 2021. The multiple linear regression measured the association between 12 independent variables and pharmacist job satisfaction.

Key findings

A total of 2137 usable surveys were received from pharmacists (54.7% female) working in 18 Arabic countries. The job satisfaction rate varied among countries in the Arab world. The fields with the highest satisfaction average included pharmaceutical marketing, academia and the pharmaceutical industry. At the same time, pharmacists working in community pharmacy and Ministry of Health/administrative positions had the lowest satisfaction rates. Overall, pharmacist satisfaction was average (3.1 out of 5). The pharmacists had the lowest satisfaction averages with income and job expectations. The pharmacists with bachelor’s degrees had significantly lower satisfaction than pharmacists with postgraduate degrees. Male pharmacists had significantly higher job satisfaction compared with female pharmacists. Workload and the feelings of organization and professional commitments had significant positive associations with job satisfaction.

Conclusions

The pharmacy profession in Arabic countries faced several challenges that negatively impacted job satisfaction. Improving work environment, professional management, income and organization loyalty is necessary to enhance pharmacist job satisfaction.

Mechanistic Basis for the Role of Phytochemicals in Inflammation-Associated Chronic Diseases

Chronic inflammatory diseases occur in a large portion of the population and are associated with a poor diet. Key natural products found in fruits and vegetables may assist in lowering inflammation associated with chronic diseases such as obesity, diabetes, cardiovascular diseases, and cancer. This review seeks to examine the roles of several natural products, resveratrol (RES), quercetin (QUE), curcumin (CUR), piperine (PIP), epigallocatechin gallate (EGCG), and gingerol (GIN), in their ability to attenuate inflammatory markers in specific diseases states. Additionally, we will discuss findings in past and ongoing clinical trials, detail possible phytochemical–drug interactions, and provide a brief resource for researchers and healthcare professionals on natural product and supplement regulation as well as names of databases with information on efficacy, indications, and natural product–drug interactions. As diet and over-the-counter supplement use are modifiable factors and patients are interested in using complementary and alternative therapies, understanding the mechanisms by which natural products have demonstrated efficacy and the types of drugs they interact with and knowing where to find information on herbs and supplements is important for practicing healthcare providers and researchers interested in this field.

A randomized controlled trial comparing the effects of Vitamin E, Ursodeoxycholic acid and Pentoxifylline on Egyptian non-alcoholic steatohepatitis patients

OBJECTIVE

Currently, no NASH-specific therapies are approved by the US Food and Drug Administration. This study aimed to compare the clinical effect of vitamin E (Vit. E), Ursodeoxycholic Acid (UDCA) and pentoxifylline (PTX) on Egyptian patients with NASH with exploration of their possible roles on inflammatory cytokines and chemokines mainly Interleukin 6 (IL6) and Monocyte Chemoattractant Protein-1 (CCL2/MCP-1).

PATIENTS AND METHODS

We conducted a 3-month, randomized, single-blind study in 102 Egyptian NASH patients who were divided into three groups; group 1 received Vit. E 400 mg twice a day, group 2 received UDCA 250 mg twice a day and group 3 received PTX 400 mg twice daily. Liver aminotransferases (AST, ALT), IL6, CCL2/MCP-1, albumin, bilirubin, and lipid panel were measured both before and after intervention intake.

RESULTS

A significant decrease was found in liver aminotransferases, serum cytokine and chemokine in participants after Vit. E, UDCA or PTX intake. Compared to the UDCA and PTX groups, liver aminotransferases, serum cytokine and chemokine showed a more statistically significant reduction after Vit. E administration (50%, 43%, 57% and 55% for ALT, AST, IL6 and CCL2/MCP-1, respectively). In contrast, other biochemical tests showed non-significant change after any drug intake. None of the tested drugs showed significant safety issues in this population.

CONCLUSIONS

Treatment with Vit. E, UDCA and PTX was both safe and effective in improving hepatic aminotransferases and inflammatory markers in Egyptian NASH patients. The superior effect of Vit. E compared to UDCA and PTX may suggest that oxidative stress plays a key role in disease progression of NASH patients. Moreover, IL6 and CCL2/MCP-1 may be used with or without ALT for treatment evaluation of NASH people.

Pharmacokinetic interaction between atorvastatin and fixed-dose combination of sofosbuvir/ledipasvir in healthy male Egyptian volunteers

PURPOSE

Comorbid conditions of heart and liver disorders added to HCV-induced hepatic steatosis make co-administration of statins, and direct-acting antivirals is common in clinical practice. This study aimed to evaluate the pharmacokinetic interaction of atorvastatin and fixed-dose combination of sofosbuvir/ledipasvir "FDCSL" with rationalization to the underlying mechanism.

METHODS

A randomized, three-phase crossover study that involves 12 healthy volunteers was performed. Participants received a single-dose of atorvastatin 80 mg alone, atorvastatin 80-mg plus tablets containing 400/90 mg FDCSL, or tablets containing 400/90 mg FDCSL alone. Plasma samples were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for atorvastatin, sofosbuvir, ledipasvir, and sofosbuvir metabolite "GS-331007," and their pharmacokinetics parameters were determined.

RESULTS

Compared to atorvastatin alone, the administration of FDCSL caused a significant increase in both areas under the concentration-time curve from time zero to infinity (AUC_0-∞) and maximum plasma concentration (C_max) of atorvastatin by 65.5% and 156.0%, respectively. Also, atorvastatin caused a significant increase in the AUC_0-∞ and C_max of sofosbuvir by 32.0% and 11.0%, respectively. Similarly, AUC_0-∞ and C_max of sofosbuvir metabolite significantly increased by 84.0% and 74.0%, respectively. However, ledipasvir AUC_0-∞ showed no significant change after atorvastatin intake. The elimination rate in all drugs revealed no significant changes.

CONCLUSION

After concurrent administration of FDCSL with atorvastatin, the AUC_0-∞ of both atorvastatin and sofosbuvir were increased. Caution should be taken with close monitoring for possible side effects after co-administration of atorvastatin and FDCSL in clinical practice.

The Impact of Fasting on Major Metabolic Pathways of Macronutrients and Pharmacokinetics Steps of Drugs

In this review, we have investigated how fasting promotes an adaptive cross-talk between different hormones and metabolic pathways to supply and meet the body's daily energy demands. We highlight in biochemical terms and mechanisms how fasting impacts four metabolic pathways-glycogenolysis, gluconeogenesis, amino acid oxidation, and fatty acid β-oxidation-that are actively engaged in the metabolism of carbohydrates, proteins, and lipids. Fasting results in reduced insulin secretion and increased glucagon and epinephrine release to prevent or stimulate metabolic reaction(s). Fasting stimulates glycogenolysis, amino acid and glucose oxidation, aminotransferase reactions in skeletal muscle, and promotes gluconeogenesis and urea production in the liver. In addition, fasting promotes gene expression of lipid metabolism in skeletal muscle, the synthesis of ketone bodies in the liver, and intracellular hormone-sensitive lipase activity in adipose tissue. Furthermore, the impact of fasting on reducing cellular damage by mitochondrial reactive oxygen species is discussed. Lastly, we briefly describe the impact of fasting on the four steps of pharmacokinetics-the absorption, distribution, metabolism, and excretion of a few select drugs-with an emphasis on the elimination of drugs related to the cytochrome-P450 family of enzymes.

Pharmacokinetic Considerations in Amputees

PURPOSE

The purpose of this article is to review the currently available assessment tools for measuring renal function, body weight, and body surface area in the amputee population.

METHODS

PubMed and Web of Science were searched using the following key terms: amputation, dose adjustment, and estimation of body weight. Articles published in languages other than English were excluded from the search.

RESULTS

Despite the increasing prevalence of amputations, there is little literature available that discusses its impact on the patient and how these physiological changes can affect pharmacokinetics. Very little information is available to guide dose adjustment in this patient population. This article discusses several factors to consider when determining optimum dosing regimens in patients with different levels of amputations.

CONCLUSION

This article will evaluate the applicability of methods mentioned in existing literature for measuring changes in renal function, body weight, and body surface area in amputees.

Development and validation of a sensitive and specific LC-MS/MS cocktail assay for CYP450 enzymes: Application to study the effect of catechin on rat hepatic CYP activity

A sensitive and specific liquid chromatography tandem mass spectrometric (LC-MS/MS) method that enables the simultaneous quantification of probe substrates and metabolites of cytochrome P450 (CYP) enzymes was developed and validated. These substrates (metabolites)-coumarin (7-hydroxycoumarin), tolbutamide (4-hydroxytolbutamide), S-mephenytoin (4-hydroxymephenytoin), dextromethorphan (dextrorphan), and testosterone (6β-hydroxytestosterone)-were utilized as markers for the activities of the major human CYP enzymes CYP2A6, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, respectively. Analytes were separated on Kinetex C₁₈ column (2.1 × 50 mm, 5 μm) using a binary gradient mobile phase of 0.1% formic acid in water and 0.1% formic acid in acetonitrile. Metabolites were detected and quantified by MS using multiple reaction monitoring at m/z 163 → 107.2 for 7-hydroxycoumarin, m/z 235 → 150.1 for 4-hydroxymephenytoin, m/z 287 → 171 for 4-hydroxytolbutamide, m/z 258 → 157.1 for dextrorphan, m/z 305 → 269 for 6β-hydroxytestosterone, and m/z 237 → 194 for the internal standard. The assay exhibited good linearity over a range of 10-500 ng/mL with acceptable accuracy and precision criteria. As a proof of concept, the developed cocktail assay was successfully used to examine the potential impact of catechin on the activity of the major rat liver CYP enzymes.

A Comprehensive Reflective Journal-Writing Framework for Pharmacy Students to Increase Self-Awareness and Develop Actionable Goals

Objective. To develop and evaluate the effectiveness of a structured model for reflective journal writing (RJW) and a grading rubric as part of a student portfolio designed to help Doctor of Pharmacy (PharmD) students create actionable goals. Methods. A structured, eight-domain format was developed to engage students in prioritization, identification, exploration, recollection, evaluation, and challenging/solidifying their own knowledge, while assembling an action plan for development (abbreviated using the acronym PIE-RECAP). After completing RJW using this model, students self-identified domains established by the Center for the Advancement of Pharmacy Education (CAPE) that corresponded to their entries. A grading rubric was designed and normalized to require minimal training for use. RJW and other elements of student portfolios were implemented simultaneously across three cohorts (N=296). Twenty-one faculty and staff graders each evaluated 10 to 15 student journal entries. Results. Of 771 journal entries, 648 (84%) met expectations, while 123 (16%) needed to be rewritten. Students identified experiences that were meaningful to them and shared in their RJW entry the knowledge and/or information that they did not know prior to the experience. Common themes identified in the students' RJWs included: curricular experiences (12.7%), cocurricular experiences (18.4%), and experiential training (68.6%). Conclusion. The PIE-RECAP method can be used to guide students in RJW and identify CAPE domains in their personal and professional experiences in pharmacy school. The associated grading rubric can be used to evaluate students' RJW entries and assess their growth in curricular, cocurricular and affective domains relative to their progression.

Pharmacokinetics and Pharmacodynamics of Promising Arginase Inhibitors

Up-regulation of arginase activity in several chronic disease conditions, including cancer and hypertension, may suggest new targets for treatment. Recently, the number of new arginase inhibitors with promising therapeutic effects for asthma, cancer, hypertension, diabetes mellitus, and erectile dysfunction has shown a remarkable increase. Arginase inhibitors may be chemical substances, such as boron-based amino acid derivatives, α-difluoromethylornithine (DMFO), and Nω-hydroxy-nor-L-arginine (nor-NOHA) or, of plant origin such as sauchinone, salvianolic acid B (SAB), piceatannol-3-O-β-D-glucopyranoside (PG) and obacunone. Despite their promising therapeutic potential, little is known about pharmacokinetics and pharmacodynamics of some of these agents. Several studies were conducted in different animal species and in vitro systems and reported significant differences in pharmacokinetics and pharmacodynamics of arginase inhibitors. Therefore, extra caution should be considered before extrapolating these studies to human. Physicochemical and pharmacokinetic profiles of some effective arginase inhibitors make it challenging to formulate stable and effective formulation. In this article, existing literature on the pharmacokinetics and pharmacodynamics of arginase inhibitors were reviewed and compared together with emphasis on possible drug interactions and solutions to overcome pharmacokinetics challenges and shortage of arginase inhibitors in clinical practice.

Assessing Propylene Glycol Toxicity in Alcohol Withdrawal Patients Receiving Intravenous Benzodiazepines: A One-Compartment Pharmacokinetic Model

BACKGROUND AND OBJECTIVES

While some case reports indicate that high doses of propylene glycol (PG) may result in metabolic acidosis, there has been no large-scale study that evaluated the risk of metabolic acidosis in patients receiving PG-containing benzodiazepines for acute alcohol withdrawal. This study was undertaken to evaluate the potential toxicity of PG in patients with acute alcohol withdrawal treated with intermittent intravenous bolus doses of diazepam and/or lorazepam.

METHODS

This is a retrospective case study using data collected from 18 randomly selected patients receiving one or both of these medications per a modified Clinical Institute Withdrawal Assessment for Alcohol (CIWA) Class 3 protocol. Plasma levels of PG were estimated using a one-compartment pharmacokinetic model.

RESULTS

Only two patients had an elevated anion gap compared to their baseline value with one also experiencing a significant increase in serum creatinine. No increases in serum osmolarity were noted. Analysis showed that the benzodiazepine dose received was a good predictor of the estimated PG concentration (r = 0.6), but was poorly correlated with the anion gap. No significant correlation was found with the creatinine clearance or serum creatinine. Patients receiving several daily doses were at higher risk of developing an anion gap (r = 0.33), but the estimated maximum PG concentration did not correlate with the anion gap or serum concentration.

CONCLUSION

It does not appear that intermittent bolus administration of intravenous benzodiazepines for alcohol withdrawal influenced renal function or anion gap regardless of number of administered doses, amount of PG received, or the estimated PG concentration.

Studying the Inhibitory Effect of Quercetin and Thymoquinone on Human Cytochrome P450 Enzyme Activities

BACKGROUND

Quercetin (QR) and thymoquinone (TQ) are herbal remedies that are currently extensively used by the general population to prevent and treat various chronic conditions. Therefore, investigating the potential of pharmacokinetic interactions caused by the concomitant use of these herbal remedies and conventional medicine is warranted to ensure patient safety.

PURPOSE OF THE STUDY

This study was conducted to determine the inhibitory effect of QR and TQ, two commonly used remedies, on the activities of selected cytochrome P450 (CYP) enzymes that play an important role in drug metabolism and/or toxicology.

MATERIALS AND METHODS

The in vitro studies were conducted using fluorescence-based high throughput assays using human c-DNA baculovirus expressed CYP enzymes. For measuring CYP2E1 activity, a validated High-performance liquid chromatography (HPLC) assay was utilized to measure the formation of 6-hydroxychlorzoxazone.

RESULTS

The obtained half-maximum inhibitory concentration values with known positive control inhibitors of this study were comparable to the published values indicating accurate experimental techniques. Although QR did not show any significant effect on CYP1A2 and CYP2E1, it exhibited a strong inhibitory effect against CYP2D6 and a moderate effect against CYP2C19 and CYP3A4. On the other hand, TQ demonstrated a strong and a moderate inhibitory effect against CYP3A4 and CYP2C19, respectively.

CONCLUSIONS

The findings of this study may indicate that consumption of QR or TQ, in the form of food or dietary supplements, with drugs that are metabolized by CYP2C19, CYP2D6, or CYP3A4 may cause significant herb-drug interactions.

SUMMARY

Neither QR nor TQ has any significant inhibitory effect on the activity of CYP1A2 or CYP2E1 enzymesBoth QR and TQ have a moderate to strong inhibitory effect on CYP3A4 activityQR has a moderate inhibitory effect on CYP2C19 and a strong inhibitory effect on CYP2D6Both QR and TQ are moderate inhibitors of the CYP2C9 activity. Abbreviations used: ABT: Aminobenztriazole, BZF: 7,8 Benzoflavone, CYP: Cytochrome P450, GB: Gingko Biloba, IC50: Half-maximum inhibitory concentration, KTZ: Ketoconazole, QND: Quinidine, QR: Quercetin, TCP: Tranylcypromine, TQ: Thymoquinone.

Inactivation of CYP2A6 by the Dietary Phenylpropanoid trans-Cinnamic Aldehyde (Cinnamaldehyde) and Estimation of Interactions with Nicotine and Letrozole

Human exposure to trans-cinnamic aldehyde [t-CA; cinnamaldehyde; cinnamal; (E)-3-phenylprop-2-enal] is common through diet and through the use of cinnamon powder for diabetes and to provide flavor and scent in commercial products. We evaluated the likelihood of t-CA to influence metabolism by inhibition of P450 enzymes. IC50 values from recombinant enzymes indicated that an interaction is most probable for CYP2A6 (IC50 = 6.1 µM). t-CA was 10.5-fold more selective for human CYP2A6 than for CYP2E1; IC50 values for P450s 1A2, 2B6, 2C9, 2C19, 2D6, and 3A4 were 15.8-fold higher or more. t-CA is a type I ligand for CYP2A6 (KS = 14.9 µM). Inhibition of CYP2A6 by t-CA was metabolism-dependent; inhibition required NADPH and increased with time. Glutathione lessened the extent of inhibition modestly and statistically significantly. The carbon monoxide binding spectrum was dramatically diminished after exposure to NADPH and t-CA, suggesting degradation of the heme or CYP2A6 apoprotein. Using a static model and mechanism-based inhibition parameters (K(I) = 18.0 µM; k(inact) = 0.056 minute(-1)), changes in the area under the concentration-time curve (AUC) for nicotine and letrozole were predicted in the presence of t-CA (0.1 and 1 µM). The AUC fold-change ranged from 1.1 to 3.6. In summary, t-CA is a potential source of pharmacokinetic variability for CYP2A6 substrates due to metabolism-dependent inhibition, especially in scenarios when exposure to t-CA is elevated due to high dietary exposure, or when cinnamon is used as a treatment of specific disease states (e.g., diabetes).

A new validated HPLC method for the determination of sulforaphane: application to study pharmacokinetics of sulforaphane in rats

A simple, accurate and reproducible high-performance liquid chromatography (HPLC) method has been developed and validated for the quantification of sulforaphane (SF) in rat plasma. The method involves a simple liquid-liquid extraction procedure to extract both SF and 7-hyrdoxycoumarin, the internal standard. The chromatographic analysis was achieved on a Shimadzu LC 20A HPLC system equipped with a Zorbax Eclipse XDB C18 column and an isocratic mobile phase consisting of 10 mm KH2 PO4 (pH 4.5) and acetonitrile HPLC grade (40:60, v/v) run at a flow rate of 1 mL/min for 10 min. The UV detection wavelength was set at 202 nm. The method exhibited good linearity (R(2) > 0.999) over the assayed concentration range (0.05-2 μg/mL) and demonstrated good intra- and inter-day precision and accuracy (relative standard deviations and the deviation from predicted values were <15%). This method was also successfully applied for studying the pharmacokinetics of SF in spontaneously hypertensive rats following single oral dietary doses of SF. The pharmacokinetics of SF show linear behavior at the dose range investigated in this study. Copyright © 2015 John Wiley & Sons, Ltd.

Dietary Doses of Sulforaphane Affect Hepatic Drug Metabolizing Enzymes in Spontaneously Hypertensive Rats

We previously demonstrated that exposure of spontaneously hypertensive rats (SHR) to dietary doses of sulforaphane (SF) results in resisting the progressive rise in blood pressure that is normally seen in these rats. This study investigates the potential effect of SF on hepatic drug metabolizing enzymes (DME) in SHR. The activity and/or protein expression of selected cytochrome P450 (CYP) enzymes and microsomal epoxide hydrolase (mEH) were measured in hepatic microsomes using specific probe substrates and/or polyclonal antibodies. Cytosolic fraction was utilized to measure protein level and activity of major antioxidant systems. The high dose SF resulted in a significant reduction of activity and apoproteins level of CYP1A2 and CYP2C9 and activities of CYP2B1/2 and mEH. No effect of SF was observed on the rest of the studied CYP enzymes. Both doses of SF resulted in a significant induction of both hepatic glutathione level and activities of superoxide dismutase and catalase. Activities of hepatic glutathione-S-transferases, glutathione reductase, and glutathione peroxidase were significantly induced only with the high dose. This study demonstrates that dietary doses of SF modulate the activity or protein expression of DME. Additionally, induction of the impaired antioxidant system in SHR may explain the blood pressure lowering effect of SF in this rat model. Copyright © 2015 John Wiley & Sons, Ltd.

Modulation of arachidonic Acid metabolism in the rat kidney by sulforaphane: implications for regulation of blood pressure

Background. We investigated the effects of sulforaphane (SF), the main active isothiocyanate in cruciferous vegetables, on arachidonic acid (AA) metabolism in the kidney and its effect on arterial blood pressure, using spontaneously hypertensive rats (SHR) as models. Methods. Rats were treated for 8 weeks with either drinking water alone (control) or SF (20 or 40 mg/kg) added to drinking water. Mean arterial pressure (MAP) was measured at 7-day intervals throughout the study. At the end of treatment rats were euthanized, and kidneys were harvested to prepare microsomes and measure enzymes involved in regulation of vasoactive metabolites: CYP4A, the key enzyme in the formation of 20-hydroxyeicosatetraenoic acid, and the soluble epoxide hydrolase, which is responsible for the degradation of the vasodilator metabolites such as epoxyeicosatetraenoic acids. Effect of SF on kidney expression of CYP4A was investigated by immunoblotting. Results. We found that treatment with SF leads to significant reductions in both, the expression and activity of renal CYP4A isozymes, as well as the activity of soluble epoxide hydrolase (sEH). Consistent with these data, we have found that treatment with SF resisted the progressive rise in MAP in the developing SHR in a dose-dependent manner. Conclusion. This is the first demonstration that SF modulates the metabolism of AA by both P450 enzymes and sEH in SHR rats. This may represent a novel mechanism by which SF protects SHR rats against the progressive rise in blood pressure.

Attenuated combined action of cyclosporine a and hyperlipidemia on atherogenesis in rabbits by thymoquinone

This descriptive study investigates in a rabbit model of atherosclerosis (i) the extent of atherogenesis induced by cyclosporine A (CsA) or hyperlipidemia alone or in combination and (ii) whether thymoquinone (TQ), a known herbal antioxidant, offers protection against these effects. New Zealand White female rabbits were assigned to five groups of six animals each: Group I, control; Group II, CsA [25 mg kg⁻¹ day⁻¹ orally (PO)]; Group III, 1% cholesterol; Group IV, 1% cholesterol + CsA (25 mg kg⁻¹ day⁻¹ PO); and Group V, 1% cholesterol + CsA (25 mg kg⁻¹ day⁻¹ PO) + TQ (10 mg kg⁻¹ day⁻¹ PO). Lipids and oxidative stress parameters [Malondialdehyde (MDA) and protein carbonyl] and aortic atherosclerosis were compared. CsA alone did not show a significant effect on either serum lipids and did not induce atherosclerosis. High-cholesterol diet induced atherosclerosis (45 ± 11% of the intimal surface of aorta was covered with atherosclerotic plaques). CsA and high-cholesterol diet increased atherosclerosis severity as measured from intimal and media lesions, but did not affect the extent of atherosclerosis. TQ decreased aortic MDA by 83%. It was also associated with reduced aortic atherosclerosis extend by 52% compared with Group IV. We concluded that (i) CsA aggravates hyperlipidemia-induced atherosclerosis and (ii) TQ attenuates the oxidative stress and atherogenesis induced by the combined effect of CsA and hyperlipidemia.

Integrative Student Learning: An Effective Team Learning Activity in a Learner-Centered Paradigm

Purpose: An Integrative Student Learning (ISL) activity was developed with the intent to enhance the dynamic of student teamwork and enhance student learning by fostering critical-thinking skills, self-directed learning skills, and active learning. Case Study: The ISL activity consists of three portions: teambuilding, teamwork, and a facilitator driven "closing the loop" feedback discussion. For teambuilding, a set of clue sheets or manufacturer's drug containers were distributed among student pairs who applied their pharmaceutical knowledge to identify two more student pairs with similar clues or drugs, thus building a team of six. For teamwork, each team completed online exams, composed of integrated pharmaceutical science questions with clinical correlates, using only selected online library resources. For the feedback discussion, facilitators evaluated student impressions, opened a discussion about the ISL activity, and provided feedback to teams' impressions and questions. This study describes three different ISL activities developed and implemented over three days with first year pharmacy students. Facilitators' interactions with students and three surveys indicated a majority of students preferred ISL over traditional team activities and over 90% agreed ISL activities promoted active learning, critical-thinking, self-directed learning, teamwork, and student confidence in online library searches. Conclusions: The ISL activity has proven to be an effective learning activity that promotes teamwork and integration of didactic pharmaceutical sciences to enhance student learning of didactic materials and confidence in searching online library resources. It was found that all of this can be accomplished in a short amount of class time with a very reasonable amount of preparation.   Type: Case Study

Learning bridge: curricular integration of didactic and experiential education

OBJECTIVES

To assess the impact of a program to integrate introductory pharmacy practice experiences with pharmaceutical science topics by promoting active learning, self-directed learning skills, and critical-thinking skills.

DESIGN

The Learning Bridge, a curriculum program, was created to better integrate the material first-year (P1) students learned in pharmaceutical science courses into their introductory pharmacy practice experiences. Four Learning Bridge assignments required students to interact with their preceptors and answer questions relating to the pharmaceutical science material concurrently covered in their didactic courses.

ASSESSMENT

Surveys of students and preceptors were conducted to measure the effectiveness of the Learning Bridge process. Feedback indicated the Learning Bridge promoted students' interaction with their preceptors as well as development of active learning, self-directed learning, and critical-thinking skills. Students also indicated that the Learning Bridge assignments increased their learning, knowledge of drug information, and comprehension of relevant data in package inserts.

CONCLUSION

The Learning Bridge process integrated the didactic and experiential components of the curriculum, enhancing student learning in both areas, and offered students educational opportunities to interact more with their preceptors.

The protective effect of thymoquinone, an anti-oxidant and anti-inflammatory agent, against renal injury: a review

Thymoquinone (TQ), 2-Isopropyl-5-methyl-1, 4-benzoquinone, is one of the most active ingredients of Nigella Sativa seeds. TQ has a variety of beneficial properties including anti-oxidative and anti-inflammatory activities. Studies have provided original observations on the role of oxidative stress and inflammation in the development of renal diseases such as glomerulonephritis and drug-induced nephrotoxicity. The renoprotective effects of TQ have been demonstrated in animal models. Also, TQ has been used successfully in treating allergic diseases in humans. The aim of this review is to highlight the importance of reactive oxygen species in renal pathophysiology and the intriguing possibility for a role of TQ in the prevention of and/or protection from renal injury in humans.

Attenuation of the development of hypercholesterolemic atherosclerosis by thymoquinone

Thymoquinone (TQ), derived from Nigella sativa seed, is an antioxidant. The present study investigated whether TQ attenuates the development of atherosclerosis, and/or reduces the serum lipid levels and oxidative stress in rabbits. New Zealand white female rabbits were assigned to four groups of six animals each: group I, control; group II, 1% cholesterol diet; group III, 1% cholesterol plus TQ (10 mg/kg/day; through a nasogastric tube) diet; and group IV, 1% cholesterol plus TQ (20 mg/kg/day; through a nasogastric tube) diet. Blood samples were collected at baseline and after four and eight weeks on the experimental diets for measurement of serum lipids, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), TC/HDL-C ratio and oxidative stress biomarkers (malondialdehyde [MDA] and protein carbonyls). At the end of the eight weeks, the aorta was removed for the assessment of atherosclerotic changes, MDA and protein carbonyls. Group II animals developed atherosclerosis (45%±11% of the intimal surface of aorta was covered with atherosclerotic plaques), which was associated with an increase in the serum TC, TG, LDL-C, HDL-C, TC/HDL-C, MDA and protein carbonyls. In group III, TQ decreased serum TC, LDL-C, MDA and protein carbonyls by 26%, 29%, 85% and 62%, respectively, and aortic MDA by 73%, which was associated with a 40% reduction of the development of aortic atherosclerosis. The higher dose of TQ in group IV had effects similar to the lower dose (group III), except that this dose further decreased serum TG. It is concluded that TQ attenuates hypercholesterolemic atherosclerosis and this effect is associated with a decrease in serum lipids and oxidative stress.

Validation of a HPLC method for the determination of p-nitrophenol hydroxylase activity in rat hepatic microsomes

We report a HPLC-UV method for determination of p-nitrophenol (PNP) hydroxylation to 4-nitrocatechol (4NC) as a marker for CYP2E1 activity in rat hepatic microsomes. Proteins were precipitated by addition of 50 microL phosphoric acid (50%, v/v in water) to 500 microL microsomal suspensions. Following vortex mixing and centrifugation the supernatant (20 microL) was injected onto a Supelcosil C(18) column (150 mm x 4.6 mm, 5 microm), and mobile phase (22% acetonitrile, 0.1% trifluoroacetic acetic acid, 0.5% triethylamine) delivered at 1.0 mL/min produced resolved peaks for internal standard, 4NC, and PNP in < 11 min. Calibration curves were linear (r(2) = 0.999) from 0.1 to 40 microM with intra- and inter-day precision < 12% and accuracy >90%. The method's improved sensitivity (LOQ = 0.1 microM) and minimal sample processing allowed rapid monitoring of PNP hydroxylase activity in fetal, neonatal, juvenile, and adult rat livers.