Drug interactions between amprenavir and methadone
| Results for the following 2 drugs: |
|---|
| amprenavir |
| methadone |
Interactions between your selected drugs
methadone ↔ amprenavir
Applies to:methadone and amprenavir
GENERALLY AVOID: Coadministration of amprenavir and methadone may result in decreased plasma concentrations of both drugs. The exact mechanism of interaction has not been described. In 16 subjects treated with methadone (44 to 100 mg daily for at least 30 days) and amprenavir (1200 mg twice a day for 10 days), mean peak plasma concentration (Cmax), systemic exposure (AUC) and trough plasma concentration (Cmin) of the active R(+) enantiomer of methadone were reduced by 25%, 13% and 21%, respectively, compared to administration of methadone alone. The combination was also associated with a 27%, 30% and 25% decrease in serum amprenavir Cmax, AUC and Cmin, respectively, compared to a non-matched historical control group.
MANAGEMENT: Given the risk of reduced viral susceptibility and resistance development associated with subtherapeutic antiretroviral drug levels, alternative antiretroviral therapy should be considered in patients treated with methadone. Patients who are prescribed the combination should be monitored for potentially reduced antiretroviral response and opiate withdrawal symptoms. Patients should be advised to notify their caregiver if they experience symptoms of methadone withdrawal such as restlessness, insomnia, sweating, lacrimation, or rhinorrhea.
See also...
Drug Interaction Classification
The classifications below are a guideline only. The relevance of a particular drug interaction to a specific patient is difficult to determine using this tool alone given the large number of variables that may apply.
| Major | Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. |
| Moderate | Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. |
| Minor | Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. |
Do not stop taking any medications without consulting your healthcare provider.
Disclaimer: Every effort has been made to ensure that the information provided by Multum is accurate, up-to-date, and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. Multum's drug information does not endorse drugs, diagnose patients, or recommend therapy. Multum's drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug of drug combination is safe, effective, or appropriate for any given patient. Multum Information Services, Inc. does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. Copyright 2000-2012 Multum Information Services, Inc. The information in contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.
