Effects of paroxetine, a CYP2D6 inhibitor, on the pharmacokinetic properties of hydrocodone after coadministration with a single-entity, once-daily, extended-release hydrocodone tablet

Evaluating Drug Interactions between Ritonavir and Opioid Analgesics: Implications from Physiologically Based Pharmacokinetic Simulation

Several commonly used opioid analgesics, such as fentanyl, sufentanil, alfentanil, and hydrocodone, are by report primarily metabolized by the CYP3A4 enzyme. The concurrent use of ritonavir, a potent CYP3A4 inhibitor, can lead to significant drug interactions. Using physiologically based pharmacokinetic (PBPK) modeling and simulation, this study examines the effects of different dosing regimens of ritonavir on the pharmacokinetics of these opioids. The findings reveal that co-administration of ritonavir significantly increases the exposure of fentanyl analogs, with over a 10-fold increase in the exposure of alfentanil and sufentanil when given with ritonavir. Conversely, the effect of ritonavir on fentanyl exposure is modest, likely due to additional metabolism pathways. Additionally, the study demonstrates that the steady-state exposure of hydrocodone and its active metabolite hydromorphone can be increased by up to 87% and 95%, respectively, with concurrent use of ritonavir. The extended-release formulation of hydrocodone is particularly affected. These insights from PBPK modeling provide valuable guidance for optimizing opioid dosing and minimizing the risk of toxicity when used in combination with ritonavir-containing prescriptions.

Child and Adolescent Bariatric Surgery in an Urban Tertiary Center: Special Anesthetic Considerations for Obesity

Children and adolescents with obesity who present for weight loss surgery are a unique subset of patients. A thorough understanding of the perioperative needs of these individuals is essential to avoid deleterious complications. This review illustrates the necessity for specialized care, including the continued need of specified drug dosing and a systematic approach in the management of the pediatric bariatric patient.

Hydrocodone, Oxycodone, and Morphine Metabolism and Drug-Drug Interactions

Awareness of drug interactions involving opioids is critical for patient treatment as they are common therapeutics used in numerous care settings, including both chronic and disease-related pain. Not only do opioids have narrow therapeutic indexes and are extensively used, but they have the potential to cause severe toxicity. Opioids are the classical pain treatment for patients who suffer from moderate to severe pain. More importantly, opioids are often prescribed in combination with multiple other drugs, especially in patient populations who typically are prescribed a large drug regimen. This review focuses on the current knowledge of common opioid drug-drug interactions (DDIs), focusing specifically on hydrocodone, oxycodone, and morphine DDIs. The DDIs covered in this review include pharmacokinetic DDI arising from enzyme inhibition or induction, primarily due to inhibition of cytochrome p450 enzymes (CYPs). However, opioids such as morphine are metabolized by uridine-5'-diphosphoglucuronosyltransferases (UGTs), principally UGT2B7, and glucuronidation is another important pathway for opioid-drug interactions. This review also covers several pharmacodynamic DDI studies as well as the basics of CYP and UGT metabolism, including detailed opioid metabolism and the potential involvement of metabolizing enzyme gene variation in DDI. Based upon the current literature, further studies are needed to fully investigate and describe the DDI potential with opioids in pain and related disease settings to improve clinical outcomes for patients. SIGNIFICANCE STATEMENT: A review of the literature focusing on drug-drug interactions involving opioids is important because they can be toxic and potentially lethal, occurring through pharmacodynamic interactions as well as pharmacokinetic interactions occurring through inhibition or induction of drug metabolism.

CYP2D6 phenotypes and opioid metabolism: the path to personalized analgesia

INTRODUCTION

Opioids play a fundamental role in chronic pain, especially considering when 1 of 5 Europeans adults, even more in older females, suffer from it. However, half of them do not reach an adequate pain relief. Could pharmacogenomics help to choose the most appropriate analgesic drug?

AREAS COVERED

The objective of the present narrative review was to assess the influence of cytochrome P450 2D6 (CYP2D6) phenotypes on pain relief, analgesic tolerability, and potential opioid misuse. Until December 2021, a literature search was conducted through the MEDLINE, PubMed database, including papers from the last 10 years. CYP2D6 plays a major role in metabolism that directly impacts on opioid (tramadol, codeine, or oxycodone) concentration with differences between sexes, with a female trend toward poorer pain control. In fact, CYP2D6 gene variants are the most actionable to be translated into clinical practice according to regulatory drug agencies and international guidelines.

EXPERT OPINION

CYP2D6 genotype can influence opioids' pharmacokinetics, effectiveness, side effects, and average opioid dose. This knowledge needs to be incorporated in pain management. Environmental factors, psychological together with genetic factors, under a sex perspective, must be considered when you are selecting the most personalized pain therapy for your patients.

A Retrospective Analysis of Selected Opioids in Hair of Workplace Drug Testing Subjects

Opioids, both naturally occurring and semisynthetic, are effective pain management medications, but also possess the potential for abuse. Analyses of over 37,000 head and body hair samples containing codeine, morphine, hydrocodone, hydromorphone, oxycodone or oxymorphone provide a view of use habits of workplace-testing subjects that cannot be obtained from fluid matrices results. Testing was performed using FDA cleared immunoassays using either 2 ng morphine or oxycodone per 10 mg hair as calibrators. Non-negative screening samples were washed with an extended aqueous wash procedure followed by LC-MS-MS confirmation at a cutoff concentration of 2 ng opioid per 10 mg hair. The LC-MS-MS method measured codeine, morphine, 6-acetylmorphine, hydrocodone, hydromorphone, oxycodone and oxymorphone with an administratively established LOQ of 0.50 ng opioid per 10 mg hair. The linear range was 0.50-100 ng morphine per 10 mg hair, and 0.50-150 ng opioid per 10 mg hair for all other measured analytes. For all analytes, within run precision was ≤5.4%, and between-run precision was ≤6.4%. Analysis of samples containing metabolites found that, among codeine positive samples, 97% contained less than 10% morphine metabolite and 88% less than 20% hydrocodone metabolite, among hydrocodone positive samples, 97% contained less than 10% hydromorphone metabolite and 95% of oxycodone positive samples contained less than 10% oxymorphone metabolite. Our analysis of opioid-positive samples may provide guidelines for interpretation of hair opioid levels typically observed in workplace testing.

Case report: relevance of metabolite identification to detect new synthetic opioid intoxications illustrated by U-47700

Today, new psychoactive substances (NPS) producers increasingly appear to be targeting new synthetic opioids (NSOs), and the recent emergence of NSOs is causing considerable concern in North America and in Europe. For toxicologists, NSO detection in a forensic context presents three additional difficulties to the general NPS analytical detection challenge: (i) high frequency of new products, (ii) low concentrations (in μg/L range and under) in biological samples related to their high opioid potency, and (iii) extensive metabolism. In this context, the present work aims to highlight the relevance of NSO metabolite detection in potential intoxication cases. Illustration is given with U-47700, an emerging NSO, (i) that was identified in a powder recently collected in France and in a fatality case, (ii) whose metabolites were in vitro produced using human liver microsomes and their mass spectra (MS) added in our MS/MS and HRMS libraries, and (iii) for which metabolism data were compared to those of the literature: U-47700 was identified in the powder and at 3040 μg/L in peripheral blood in the fatality case. In addition, high amounts of several U-47700 metabolites, especially N-desmethyl-U-47700, were observed in urine. Even if metabolite formation may largely depend on the enzymatic activity as well as on the length of the survival time, confrontation of these results to data found in the literature strongly suggests that this metabolite is regularly a better blood and (mainly) urine biomarker of U-47700 intake than U-47700 itself. Indeed, in this fatality and in other previous reports, N-desmethyl-U-47700 produced the main observed chromatographic signal (i) systematically in vitro and (ii) commonly in vivo, especially in urines. N,N-Didesmethyl-U-47700 is also sometimes a better biomarker of U-47700 intake than U-47700 itself. Accordingly, we suggest adding N-desmethyl-U-47700 (and N,N-didesmethyl-U-47700) in mass spectrum databases used for toxicological screening in order to reduce the risk of false-negative results in intoxication cases involving U-47700.

Opioid analgesics-related pharmacokinetic drug interactions: from the perspectives of evidence based on randomized controlled trials and clinical risk management

BACKGROUND

Multimorbidity results in complex polypharmacy which may bear a risk of drug interactions. A better understanding of opioid analgesics combination therapy used for pain management could help warrant medication safety, efficacy, and economic relevance. Until now there has been no review summarizing the opioid analgesics-related pharmacokinetic drug interactions from the perspective of evidence based on randomized controlled trials (RCTs).

METHOD

A literature search was performed using PubMed, MEDLINE, and the Cochrane Library, using a PRISMA flowchart.

RESULTS

Fifty-two RCTs were included for data interpretation. Forty-two RCTs (80.8%) were conducted in healthy volunteers, whereas 10 RCTs (19.2%) enrolled true patients. None of the opioid-drug/herb pairs was listed as contraindications of opioids involved in this review. Circumstances in which opioid is comedicated as a precipitant drug include morphine-P2Y12 inhibitors, morphine-gabapentin, and methadone-zidovudine. Circumstances in which opioid is comedicated as an object drug include rifampin-opioids (morphine, tramadol, oxycodone, methadone), quinidine-opioids (morphine, fentanyl, oxycodone, codeine, dihydrocodeine, methadone), antimycotics-opioids (buprenorphine, fentanyl, morphine, oxycodone, methadone, tilidine, tramadol), protease inhibitors-opioids (ritonavir, ritonavir/lopinavir-oxycodone, ritonavir-fentanyl, ritonavir-tilidine), grapefruit juice-opioids (oxycodone, fentanyl, methadone), antidepressants-opioids (paroxetine-tramadol, paroxetine-hydrocodone, paroxetine-oxycodone, escitalopram-tramadol), metoclopramide-morphine, amantadine-morphine, sumatriptan-butorphanol nasal sprays, ticlopidine-tramadol, St John's wort-oxycodone, macrolides/ketolides-oxycodone, and levomepromazine-codeine. RCTs investigating the same combination, almost unanimously, drew consistent conclusions, except two RCTs on amantadine-intravenous morphine combination where a different amantadine dose was used and two RCTs on morphine-ticagrelor combination where healthy volunteers and true patients were enrolled, respectively. RCTs investigating in true patients may reflect a realistic clinical scenario and overcome the limitation of RCTs performed in healthy volunteers under standardized conditions. Further research opportunities are also presented in this review.

CONCLUSION

Effective and safe combination therapy of opioids can be achieved by promoting the awareness of potential changes in therapeutic efficacy and toxicities, prescribing alternatives or changing administration strategy, tailoring dose, reviewing the appropriateness of orders, and paying attention to medication monitoring.