Methadone toxicity due to smoking cessation--a case report on the drug-drug interaction involving cytochrome P450 isoenzyme 1A2

Genetic Variants Associated with Opioid Use Disorder

Genetics are presumed to contribute 30-40% to opioid use disorder (OUD), allowing for the possibility that genetic markers could be used to identify personal risk for developing OUD. We aimed to test the potential association among 180 candidate single nucleotide polymorphisms (SNPs), 120 of which were related to the dopamine reward pathway and 60 related to pharmacokinetics. Participants were randomly recruited in 2020-2021 in a cross-sectional genetic association study. Self-reported health history including Diagnostic and Statistical Manual of Mental Disorders (DSM-5) OUD criteria and buccal swabs were collected. A total of 1,301 participants were included in the analyses for this study. Of included participants, 250 met the DSM-5 criteria for ever having OUD. Logistic regression, adjusting for age and biologic sex, was used to characterize the association between each SNP and DSM-5 criteria consistent with OUD. Six SNPs found in 4 genes were associated with OUD: increased odds with CYP3A5 (rs15524 and rs776746) and DRD3 (rs324029 and rs2654754), and decreased odds with CYP3A4 (rs2740574) and CYP1A2 (rs2069514). Homozygotic CYP3A5 (rs15524 and rs776746) had the highest adjusted odds ratio of 2.812 (95% confidence interval (CI) 1.737, 4.798) and 2.495 (95% CI 1.670, 3.835), respectively. Variants within the dopamine reward and opioid metabolism pathways have significant positive (DRD3 and CYP3A5) and negative (CYP3A4 and CYP1A2) associations with OUD. Identification of these variants provides promising possibilities for genetic prognostic and therapeutic targets for future investigation.

Drug-Drug Interaction Between Orally Administered Hydrocodone-Acetaminophen and Inhalation of Cannabis Smoke: A Case Report

Objective

To determine if a 2-day protocol measuring pharmacokinetic and pharmacodynamic characteristics can demonstrate drug-drug interactions when smoked cannabis is added to orally administered hydrocodone/acetaminophen combination products.

Case Summary

A 51-year-old non-Hispanic white male with chronic pain diagnoses participated in a 2-day pilot protocol. The participant attended two 7-hour in-lab days where he received 10 blood draws each day and completed self-administered pain and anxiety surveys. For both days, the participant took his prescribed dose of hydrocodone/acetaminophen (1/2 tablet of 7.5 mg/325 mg combination product) with the addition of 1 smoked pre-rolled marijuana cigarette (labeled as 0.5 g; 22.17% Δ9-tetrahydrocannabinol; 0.12% cannabidiol) on Day 2. Blood specimens were analyzed using mass spectrometry to quantify the difference of plasma hydrocodone levels between Day 1 and Day 2.

Results

Compared to Day 1, lower levels of pain and anxiety were reported during Day 2 with the addition of cannabis to oral hydrocodone/acetaminophen. Day 2 pharmacokinetic analysis also revealed more rapid absorption and overall lower levels of hydrocodone in plasma.

Discussion

Lower hydrocodone plasma levels in Day 2 may indicate cannabis's effect on metabolism and reduce the risk of opioid toxicity. The quicker absorption rate of hydrocodone could explain lower pain and anxiety scores reported on the second day.

Conclusion and Relevance

A 2-day protocol was able to capture differences across time in pharmacokinetic and pharmacodynamic measurements. Larger studies can be designed to better characterize the potential drug-drug interaction of cannabis and opioids.

Interaction between methadone and clarithromycin as the suspected cause of an opioid toxidrome

A 40-year-old patient was admitted through the acute medical take with pleuritic chest pain and rigours. He had a medical history of opiate dependence and was receiving 60 mg of methadone once daily. He was diagnosed with a community-acquired pneumonia and treated with amoxicillin and clarithromycin. After administration of only two concomitant doses of methadone and oral clarithromycin, he developed an opioid toxidrome with type-2 respiratory failure, a decreased level of consciousness and pinpoint pupils. The patient was treated with naloxone and his symptoms improved. Retrospectively, it was suspected that an interaction between clarithromycin and methadone might have contributed to the toxidrome. Respiratory failure has not been previously prescribed for this combination of medication and is of high importance for physicians and pharmacists around the world.

[Relation between tobacco smoking and pain: A narrative review of the scientific literature]

INTRODUCTION

Tobacco smoking and pain have an intimate, complex, two-way interaction. The purpose of this narrative review of the literature is to present what is currently understood about the relationship.

STATE OF KNOWLEDGE

Tobacco smoking (and the associated chronic exposure to nicotine) has been defined as a risk factor for chronic pain, involving nociceptive sensitisation. For people who smoke, pain will be both a motivational factor for tobacco consumption and a barrier to tobacco use cessation. Conversely, nicotine (acute exposure) has clearly demonstrated analgesic properties, mediated in particular by activation of nicotinic acetylcholine receptors.

PERSPECTIVES

The management of pain in people who smoke is still largely unaddressed, and further studies will be needed to develop effective strategies for tobacco use cessation in this context. Nicotine and modulators of nicotinic acetylcholine receptors represent innovative strategies for the discovery of new analgesics.

CONCLUSIONS

The effects of smoking on pain, chronic nociceptive sensitisation and acute analgesia, serve to maintain tobacco consumption via negative reinforcement. A holistic therapeutic strategy is necessary to maximise the likelihood of successful smoking cessation.

Nicotine and Opioids: a Call for Co-treatment as the Standard of Care

The U.S. is in the midst of an opioid epidemic. At the same time, tobacco use remains the leading cause of preventable death and disability. While the shared biological underpinnings of nicotine and opioid addiction are well established, clinical implications for co-treatment of these two substance use disorders has not been emphasized in the literature, nor have researchers, clinicians, and policy makers adequately outlined pathways for incorporating co-treatment into existing clinical workflows. The current brief review characterizes the metabolic and neural mechanisms which mediate co-use of nicotine and opioids, and then outlines clinical and policy implications for concurrently addressing these two deadly epidemics. Screening, assessment, medication-assisted treatment (MAT), and tobacco-free policy are discussed. The evidence suggests that clinical care and policies that facilitate co-treatment are an expedient means of delivering healthcare to individuals that result in better health for the population while also meeting patients' substance abuse disorder recovery goals.

Potential drug-drug interactions associated with drugs currently proposed for COVID-19 treatment in patients receiving other treatments

Patients with COVID-19 are sometimes already being treated for one or more other chronic conditions, especially if they are elderly. Introducing a treatment against COVID-19, either on an outpatient basis or during hospitalization for more severe cases, raises the question of potential drug-drug interactions. Here, we analyzed the potential or proven risk of the co-administration of drugs used for the most common chronic diseases and those currently offered as treatment or undergoing therapeutic trials for COVID-19. Practical recommendations are offered, where possible.

Characterization of the Safety and Pharmacokinetic Profile of D-Methadone, a Novel N-Methyl-D-Aspartate Receptor Antagonist in Healthy, Opioid-Naive Subjects: Results of Two Phase 1 Studies

PURPOSE/BACKGROUND

N-methyl-D-aspartate (NMDA) receptor (NMDAR) antagonists are potential agents for the treatment of several central nervous system disorders including major depressive disorder. Racemic methadone, L-methadone, and D-methadone all bind the NMDAR with an affinity similar to that of established NMDAR antagonists, whereas only L-methadone and racemic methadone bind to opioid receptors with high affinity. Therefore, D-methadone is expected to have no clinically significant opioid effects at therapeutic doses mediated by its NMDAR antagonism.

METHODS

We conducted 2 phase 1, double-blind, randomized, placebo-controlled, single- and multiple-ascending-dose studies to investigate the safety and tolerability of oral D-methadone and to characterize its pharmacokinetic profile in healthy opioid-naive volunteers.

RESULTS

D-Methadone exhibits linear pharmacokinetics with dose proportionality for most single-dose and multiple-dose parameters. Single doses up to 150 mg and daily doses up to 75 mg for 10 days were well tolerated with mostly mild treatment-emergent adverse events and no severe or serious adverse events. Dose-related somnolence and nausea occurred and were mostly present at the higher dose level. There was no evidence of respiratory depression, dissociative and psychotomimetic effects, or withdrawal signs and symptoms upon abrupt discontinuation. An overall dose-response effect was observed, with higher doses resulting in larger QTcF (QT interval corrected using Fridericia formula) changes from baseline, but none of the changes were considered clinically significant by the investigators. Mild, dose-dependent pupillary constriction of brief duration occurred particularly at the 60-mg dose or above in the single-ascending-dose study and at the dose of 75 mg in the multiple-ascending-dose study. No detectable conversion of D-methadone to L-methadone occurred in vivo.

CONCLUSIONS

These results support the safety and continued clinical development of D-methadone as an NMDAR antagonist for the treatment of depression and other central nervous system disorders.

Safe and Appropriate Use of Methadone in Hospice and Palliative Care: Expert Consensus White Paper

Methadone has several unique characteristics that make it an attractive option for pain relief in serious illness, but the safety of methadone has been called into question after reports of a disproportionate increase in opioid-induced deaths in recent years. The American Pain Society, College on Problems of Drug Dependence, and the Heart Rhythm Society collaborated to issue guidelines on best practices to maximize methadone safety and efficacy, but guidelines for the end-of-life scenario have not yet been developed. A panel of 15 interprofessional hospice and palliative care experts from the U.S. and Canada convened in February 2015 to evaluate the American Pain Society methadone recommendations for applicability in the hospice and palliative care setting. The goal was to develop guidelines for safe and effective management of methadone therapy in hospice and palliative care. This article represents the consensus opinion of the hospice and palliative care experts for methadone use at end of life, including guidance on appropriate candidates for methadone, detail in dosing, titration, and monitoring of patients' response to methadone therapy.

Tobacco smoking and its drug interactions with comedications involving CYP and UGT enzymes and nicotine

Tobacco smoking is a global public health threat causing several illnesses including cardiovascular disease (Myocardial infarction), cerebrovascular disease (Stroke), peripheral vascular disease (Claudication), chronic obstructive pulmonary disease, asthma, reduced female infertility, sexual dysfunction in men, different types of cancer and many other diseases. It has been estimated in 2015 that approximately 1.3 billion people smoke, around the globe. Use of medications among smokers is more common, nowadays. This review is aimed to identify the medications affected by smoking, involving Cytochrome P450 (CYP) and uridine diphosphate-glucuronosyltransferases (UGTs) enzymes and Nicotine. Polycyclic aromatic hydrocarbons (PAHs) of tobacco smoke have been associated with the induction of CYP enzymes such as CYP1A1, CYP1A2 and possibly CYP2E1 and UGT enzymes. The drugs metabolized by CYP1A1, CYP1A2, CYP2E1 and UGT enzymes might be affected by tobacco smoking and the smokers taking medications metabolized by those enzymes, may need higher doses due to decreased plasma concentrations through enhanced induction by PAHs of tobacco smoke. The prescribers and the pharmacists are required to be aware of medications affected by tobacco smoking to prevent the toxicity-associated complications during smoking cessation.

A narrative review of the safety concerns of deprescribing in older adults and strategies to mitigate potential harms

INTRODUCTION

As with prescribing or continuing medications, deprescribing brings with it the potential for harm as well as benefit. Uncertainty and avoidance of harm has been reported as a barrier to deprescribing in practice and may contribute to continuation of inappropriate medications.

AREAS COVERED

This narrative review covers four main safety concerns/potential harms of deprescribing in older adults: adverse drug withdrawal events, return of medical condition(s), reversal of drug-drug interactions and damage to the doctor-patient relationship. These are discussed in relation to medications in general, with some examples of medication classes used to illustrate the potential safety concerns. The majority of these harms can be minimized or even prevented by using a patient-centered, structured deprescribing process with planning, tapering and close monitoring during, and after medication withdrawal.

EXPERT OPINION

More research is needed into the safety concerns of deprescribing, however, avenues exist during drug development and post-marketing surveillance to gain knowledge on this topic. Questions remain about when it is suitable to discontinue certain medications/medication classes and there is uncertainty about the harms and benefits of both medication continuation and discontinuation in complex older adults.

The Opioid Epidemic: What Does it Mean for Nurses?

The United States is facing a major crisis with the current opioid epidemic. Tens of thousands of individuals are dying each year due to abuse and misuse of heroin and prescription opiate drugs. Nurses play an integral role in these aspects of health care and offer solutions by providing education; preventive measures; treatments, including medication-assisted treatments (MATs); and ongoing recovery options for individuals with opioid use disorders. Nurses provide education, issue prescriptions and dispense medications, and provide overall physical and mental health care to patients struggling with this "disease of the brain," and with the signing of the Comprehensive Addiction and Recovery Act, advanced practice RNs will soon be able to include MATs related to buprenorphine as part of their treatment plan. The current article explores the anatomy, physiology, and genetics of addiction and how they relate to the pharmacological MATs used to treat opioid use disorders. [Journal of Psychosocial Nursing and Mental Health Services, 55(1), 18-23.].

Opioid Analgesics and Nicotine: More Than Blowing Smoke

Practitioners are highly likely to encounter patients with concurrent use of nicotine products and opioid analgesics. Smokers present with more severe and extended chronic pain outcomes and have a higher frequency of prescription opioid use. Current tobacco smoking is a strong predictor of risk for nonmedical use of prescription opioids. Opioid and nicotinic-cholinergic neurotransmitter systems interact in important ways to modulate opioid and nicotine effects: dopamine release induced by nicotine is dependent on facilitation by the opioid system, and the nicotinic-acetylcholine system modulates self-administration of several classes of abused drugs-including opioids. Nicotine can serve as a prime for the use of other drugs, which in the case of the opioid system may be bidirectional. Opioids and compounds in tobacco, including nicotine, are metabolized by the cytochrome P450 enzyme system, but the metabolism of opioids and tobacco products can be complicated. Accordingly, drug interactions are possible but not always clear. Because of these issues, asking about nicotine use in patients taking opioids for pain is recommended. When assessing patient tobacco use, practitioners should also obtain information on products other than cigarettes, such as cigars, pipes, smokeless tobacco, and electronic nicotine delivery systems (ENDS, or e-cigarettes). There are multiple forms of behavioral therapy and pharmacotherapy available to assist patients with smoking cessation, and opioid agonist maintenance and pain clinics represent underutilized opportunities for nicotine intervention programs.

Clinical pharmacist's role in implementing a smoking cessation intervention in a Swiss regional hospital: an exploratory study

BACKGROUND

Smoking cessation represents one of the best means of preventing smoking-related complications. In recent years, a majority of hospitals have implemented smoke-free policies, making support for smoker patients a necessary and indispensable task. The clinical pharmacist is well-positioned to provide this kind of support, given a good understanding of the medical condition and pharmacotherapy of hospitalized patients and the possibility to acquire specific smoking cessation training.

OBJECTIVES

This study aimed to evaluate the impact of a smoking cessation intervention for hospitalized patients by a clinical pharmacist previously trained for smoking cessation counselling.

SETTING

Internal medicine department of a Swiss regional hospital.

METHOD

Smoker patients hospitalized in this department were included in the study from mid-September 2012 to mid-January 2013, according to the inclusion criteria. Moderate-intensity smoking cessation interventions based on smoking counselling and motivational interviewing techniques were used, and a follow-up telephone call at least 1 month after discharge was made. Patients' pharmacotherapy was analysed with regards to interactions with tobacco smoke.

MAIN OUTCOME MEASURES

Motivational stage, abstinence at follow-up, change of readiness to quit between hospital visit and follow-up, patients' evaluation of the programme, pharmacotherapy interventions.

RESULTS

One hundred smoker patients were screened, of whom 41 received the intervention and 40 received a follow-up contact. At least 1 month after discharge, the readiness to quit of 53 % of patients improved and 33 % of patients declared themselves abstinent. Even though 35 % of patients declared having mild to moderate withdrawal symptoms in hospital, only 15 % were interested in receiving nicotine replacement therapy. Study participants evaluated the intervention positively.

CONCLUSION

A moderate-intensity smoking cessation intervention in hospitalized patients was associated with a higher quit rate than in control groups from other studies, and their readiness to quit generally improved at least 1 month after hospital discharge. A clinical pharmacist trained for smoking cessation counselling can play a key role in providing such interventions, including the assessment of pharmacotherapy interactions with tobacco smoke.

Meta-analysis: the effects of smoking on the disposition of two commonly used antipsychotic agents, olanzapine and clozapine

OBJECTIVE

To clarify the effects of smoking on the disposition of two commonly used antipsychotics, olanzapine and clozapine, and to create standards to adjust the doses of these drugs in clinical practice based on the smoking status.

DESIGN

A meta-analysis was conducted by searching MEDLINE, Scopus and the Cochrane Library for relevant prospective and retrospective studies.

INCLUDED STUDIES

We included the studies that investigated the effects of smoking on the concentration to dose (C/D) ratio of olanzapine or clozapine.

PRIMARY OUTCOME MEASURE

The weighted mean difference was calculated using a DerSimonian-Laird random effects model, along with 95% CI.

RESULTS

Seven association studies, comprising 1094 patients (652 smokers and 442 non-smokers) with schizophrenia or other psychiatric disorders, were included in the meta-analysis of olanzapine. The C/D ratio was significantly lower in smokers than in non-smokers (p<0.00001), and the mean difference was -0.75 (ng/mL)/(mg/day) (95% CI -0.89 to -0.61). Therefore, it was estimated that if 10 and 20 mg/day of olanzapine would be administered to smokers, about 7 and 14 mg/day, respectively, should be administered to non-smokers in order to obtain the equivalent olanzapine concentration. Four association studies of clozapine were included in the meta-analysis of clozapine, comprising 196 patients (120 smokers and 76 non-smokers) with schizophrenia or other psychiatric disorders. The C/D ratio was significantly lower in smokers than in non-smokers (p<0.00001), and the mean difference was -1.11 (ng/mL)/(mg/day) (95% CI -1.53 to -0.70). Therefore, it was estimated that if 200 and 400 mg/day of clozapine would be administered to smokers, about 100 and 200 mg/day, respectively, should be administered to non-smokers.

CONCLUSIONS

We suggest that the doses of olanzapine and clozapine should be reduced by 30% and 50%, respectively, in non-smokers compared with smokers in order to obtain an equivalent olanzapine or clozapine concentration.

Smoking and opioid detoxification: behavioral changes and response to treatment

INTRODUCTION

The relevance of tobacco use in opioid addiction (OA) has generated a demand for available and more effective interventions. Thus, further analysis of less explored nicotine-opioid clinical interactions is warranted.

METHODS

A post-hoc analysis of OA participants in a double-blind, randomized very low dose naltrexone (VLNTX) inpatient detoxification trial evaluated measures of opioid withdrawal and tobacco use. Intreatment smokers were compared with nonsmokers, or smokers who were not allowed to smoke.

RESULTS

A total of 141 (81%) of 174 OA participants were smokers, all nicotine-dependent. Inpatient smoking was a predictor of opioid withdrawal discomfort. Intreatment smokers (n = 96) showed significantly higher opioid craving (F = 3.7, p < .001) and lower detoxification completion rate (χ(2) = 7.9, p < .02) compared with smokers who were not allowed to smoke (n = 45) or nonsmokers (n = 33). Smoking during treatment was associated with more elevated cigarette craving during detoxification (F = 4.1, p < .001) and a higher number of cigarettes smoked at follow-up (F = 3.6, p < .02). Among intreatment smokers, VLNTX addition to methadone taper was effective in easing opioid withdrawal and craving more than other treatments, whereas the combination VLNTX-clonidine was associated with significantly reduced cigarette craving and smoking during detoxification.

CONCLUSIONS

Failure to address tobacco use may negatively affect pharmacologically managed opioid discontinuation. Opioid detoxification may offer a window of opportunity to expand smoking cessation treatment, hence improving OA outcomes. The observed effects support testing of VLNTX-clonidine in smoking cessation trials among individuals with or without substance abuse.

The clinical implications of cytochrome p450 interactions with opioids and strategies for pain management

Pharmacokinetic differences among opioids influence a patient's response to opioid treatment. An important element affecting a drug's pharmacokinetics, its metabolism, may be altered under various circumstances, thereby enhancing or mitigating a patient's response to opioids. The genetic background of the metabolic enzymes involved in opioid metabolism, comorbid medical conditions, older age, and the presence of other drugs that influence metabolism are such factors that can cause the response to opioid therapy to vary greatly from the expected response to a standard dose. As a result of the variability in individual responses to opioids, clinical management of pain with opioids must be empirical.