Effect of an acute dose of alcohol on the pharmacokinetics of oral nifedipine in humans

Alcohol-medication interactions: A systematic review and meta-analysis of placebo-controlled trials

Alcohol and other xenobiotics may limit the therapeutic effects of medications. We aimed at investigating alcohol-medication interactions (AMI) after the exclusion of confounding effects related to other xenobiotics. We performed a systematic review and meta-analysis of controlled studies comparing the effects induced by alcohol versus placebo on pharmacodynamic and/or pharmacokinetic parameters of approved medications. Certainty in the evidence of AMI was assessed when at least 3 independent studies and at least 200 participants were available. We included 107 articles (3097 participants): for diazepam, cannabis, opioids, and methylphenidate, we found significant AMI and enough data to assign the certainty of evidence. Alcohol consumption significantly increases the peak plasma concentration of diazepam (low certainty; almost 290 participants), cannabis (high certainty; almost 650 participants), opioids (low certainty; 560 participants), and methylphenidate (moderate certainty; 290 participants). For most medications, we found some AMI but not enough data to assign them the certainty grades; for some medications, we found no differences between alcohol and placebo in any outcomes evaluated. Our results add further evidence for interactions between alcohol and certain medications after the exclusion of confounding effects related to other xenobiotics. Physicians should advise patients who use these specific medications to avoid alcohol consumption. Further studies with appropriate control groups, enough female participants to investigate sex differences, and elderly population are needed to expand our knowledge in this field. Short phrases suitable for indexing terms.

Understanding and predicting the impact of critical dissolution variables for nifedipine immediate release capsules by multivariate data analysis

In this study the selection of in vivo predictive in vitro dissolution experimental set-ups using a multivariate analysis approach, in line with the Quality by Design (QbD) principles, is explored. The dissolution variables selected using a design of experiments (DoE) were the dissolution apparatus [USP1 apparatus (basket) and USP2 apparatus (paddle)], the rotational speed of the basket/or paddle, the operator conditions (dissolution apparatus brand and operator), the volume, the pH, and the ethanol content of the dissolution medium. The dissolution profiles of two nifedipine capsules (poorly soluble compound), under conditions mimicking the intake of the capsules with i. water, ii. orange juice and iii. an alcoholic drink (orange juice and ethanol) were analysed using multiple linear regression (MLR). Optimised dissolution set-ups, generated based on the mathematical model obtained via MLR, were used to build predicted in vitro-in vivo correlations (IVIVC). IVIVC could be achieved using physiologically relevant in vitro conditions mimicking the intake of the capsules with an alcoholic drink (orange juice and ethanol). The multivariate analysis revealed that the concentration of ethanol used in the in vitro dissolution experiments (47% v/v) can be lowered to less than 20% v/v, reflecting recently found physiological conditions.

Pharmacokinetic and pharmacodynamic drug interactions with ethanol (alcohol)

Ethanol (alcohol) is one of the most widely used legal drugs in the world. Ethanol is metabolized by alcohol dehydrogenase (ADH) and the cytochrome P450 (CYP) 2E1 drug-metabolizing enzyme that is also responsible for the biotransformation of xenobiotics and fatty acids. Drugs that inhibit ADH or CYP2E1 are the most likely theoretical compounds that would lead to a clinically significant pharmacokinetic interaction with ethanol, which include only a limited number of drugs. Acute ethanol primarily alters the pharmacokinetics of other drugs by changing the rate and extent of absorption, with more limited effects on clearance. Both acute and chronic ethanol use can cause transient changes to many physiologic responses in different organ systems such as hypotension and impairment of motor and cognitive functions, resulting in both pharmacokinetic and pharmacodynamic interactions. Evaluating drug interactions with long-term use of ethanol is uniquely challenging. Specifically, it is difficult to distinguish between the effects of long-term ethanol use on liver pathology and chronic malnutrition. Ethanol-induced liver disease results in decreased activity of hepatic metabolic enzymes and changes in protein binding. Clinical studies that include patients with chronic alcohol use may be evaluating the effects of mild cirrhosis on liver metabolism, and not just ethanol itself. The definition of chronic alcohol use is very inconsistent, which greatly affects the quality of the data and clinical application of the results. Our study of the literature has shown that a significantly higher volume of clinical studies have focused on the pharmacokinetic interactions of ethanol and other drugs. The data on pharmacodynamic interactions are more limited and future research addressing pharmacodynamic interactions with ethanol, especially regarding the non-central nervous system effects, is much needed.

The effects of alcohol on the metabolism and toxicology of anti-psoriasis drugs

INTRODUCTION

Alcohol has long been suspected to be a triggering and precipitating factor of psoriasis. Alcohol misuse is common in patients with moderate-to-severe psoriasis and appears to impair treatment outcome.

AREAS COVERED

In this article, the authors review the available data regarding the metabolic and toxicological interactions between anti-psoriasis systemic drugs and ethanol and/or alcoholic beverages. Special attention is given to the influence of alcohol consumption on the hepatotoxic risk of some anti-psoriasis drugs. The article was prepared using a MEDLINE literature search.

EXPERT OPINION

The available knowledge highlights the existence of a few significant pharmacological interactions, such as the reduced exposure to cyclosporine by red wine, the possible increase of cyclosporine levels following a heavy acute alcohol intake, and, especially, the conversion of acitretin to etretinate, in the presence of ethanol, with important implications in females of child-bearing potential. There are limited data on the contributing role of alcohol in the hepatotoxicity induced by some anti-psoriasis drugs and the existing information on this topic is still controversial. However, further investigation is needed to assess the relevance of interactions between alcohol consumption and drug therapy for psoriasis, under both pharmacological and toxicological perspectives. Long-term prospective studies on large cohorts of patients are warranted to disclose the actual significance of such potential interactions in clinical practice.

Ethanol inhibits in-vitro metabolism of nifedipine, triazolam and testosterone in human liver microsomes

Although extended exposure to ethanol induces CYP3A metabolism in-vivo, the acute effects of ethanol on CYP3A metabolism have not been fully evaluated in-vitro. We assessed the effect of ethanol on CYP3A-mediated biotransformation using human liver microsomes in-vitro with three prototypic CYP3A-mediated reactions: nifedipine to oxidized nifedipine, triazolam to its 1-hydroxy (1-OH TRZ) and 4-hydroxy (4-OH TRZ) metabolites, and testosterone to 6β-hydroxytestosterone (6β-OH TST). Ethanol inhibited metabolism of nifedipine (oxidized nifedipine IC50 3 mg dL−1, where the IC50 value is the inhibitor concentration corresponding to a 50% reduction in metabolite formation velocity), triazolam (1-OH TRZ IC50 1.1 mg dL−1, 4-OH TRZ IC50 2.7 mg dL−1) and testosterone (6β-OH TST IC50 2.4 mg dL−1). The inhibitory potency of ethanol was similar for the three substrates representing the three hypothetical CYP3A substrate categories. The IC50 values obtained were lower than clinically relevant blood alcohol concentrations. In conclusion, ethanol is an inhibitor of human CYP3A metabolism and may contribute to clinically important interactions.

Amlodipine overdose

OBJECTIVE

To report a nonfatal intentional overdose of amlodipine.

CASE SUMMARY

A 42-year-old woman with a history of hypertension reported ingesting 50-100 mg amlodipine besylate and at least 40 ounces of beer in a suicide attempt. The patient's symptoms were mild; BP ranged from 79/50 to 113/76 mm Hg and HR from 92 to 129 beats/min (sinus tachycardia). Laboratory studies revealed normoglycemia, mild metabolic acidosis, mild hypocalcemia, blood ethanol concentration of 263 mmol/L, and a serum amlodipine concentration of 88 ng/mL (normal 3-11) 2.5 hours after ingestion. Therapy included activated charcoal, whole bowel irrigation, and intravenous NaCl 0.9%. After receiving 1.5 L of NaCl 0.9%, the patient developed signs of mild pulmonary edema that resolved over several hours without intervention. A serum amlodipine concentration obtained 35 hours later was 79 mg/mL. The patient was discharged on day 2 in good condition.

DISCUSSION

In this case, an amlodipine overdose was associated with sustained hypotension and sinus tachycardia, as well as transient pulmonary edema following relatively low-volume fluid replacement. A previously published report described an amlodipine overdose that was fatal due to refractory hypotension and was complicated by concomitant oxazepam overdose.

CONCLUSIONS

Amlodipine overdose produces prolonged hemodynamic effects and may lead to pulmonary edema. Due to a long elimination half-life and delayed onset of effects, patients with amlodipine overdose should receive aggressive decontamination therapy and may require extended clinical monitoring and supportive care if they are hemodynamically unstable.

Lack of presystemic metabolism of nifedipine in the rabbit

In humans, oral bioavailability of nifedipine has been reported to be around 60%, although the organ(s) contributing to its first-pass metabolism have not been determined. The aim of this study was to determine in vivo, in anesthetized and conscious rabbits the role of the intestine, liver, and lungs in the first-pass metabolism of nifedipine. To assess the extraction of nifedipine by the intestine, liver, and lungs, nifedipine was administered before and after each organ, and serial blood samples were withdrawn from an artery. In conscious rabbits, the systemic clearance of nifedipine injected into a lateral vein of an ear was 14.6 +/- 1.6 ml/min per kg, a value that was slightly decreased by anesthesia. In anesthetized rabbits, compared to the clearance estimated when nifedipine was administered into the thoracic aorta, the administration of nifedipine into a jugular vein, into the portal vein, or into the portal vein, or into the duodenum did not increase the value of the systemic clearance. In conscious rabbits, the clearance of nifedipine estimated when the drug was administered into the duodenum, the peritoneum, the portal vein, or into the jugular vein was identical to the clearance calculated when the drug was injected into the thoracic aorta. In vitro, nifedipine was metabolized in liver and intestinal epithelial cells homogenates but not in lungs or kidneys. We concluded that in the rabbit, oral nifedipine is not subjected to a first-pass metabolism, even though the intestine and the liver may contribute to nifedipine systemic clearance.