Methadone with Itraconazole Interaction Details
Brand Names Associated with Methadone
- Diskets®
- Dolophine®
- Methadone
- Methadose®
- Methadose® Oral Concentrate
- Westadone®
Brand Names Associated with Itraconazole
- Itraconazole
- Onmel®
- Sporanox®
- Tolsura®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jan 02, 2024
Interaction Effect
Increased serum methadone levels and an increased risk of respiratory depression and hypotension
Interaction Summary
Coadministration of itraconazole and methadone, as well as use for up to 2 weeks following itraconazole discontinuation, is contraindicated due to a risk of significantly increased methadone exposureand a risk of methadone toxicity, including respiratory depression and hypotension .
Severity
Contraindicated
Onset
Delayed
Evidence
Probable
How To Manage Interaction
Coadministration of itraconazole and methadone, as well as use for up to 2 weeks following itraconazole discontinuation, is contraindicated due to a risk of significantly increased methadone exposureand a risk of methadone toxicity, including respiratory depression and hypotension .
Mechanism Of Interaction
Inhibition of CYP3A4-mediated methadone metabolism
Literature Reports
A) A 44-year-old woman on methadone treatment for heroin dependence developed QTc interval prolongation, leading to torsade de pointes, following concomitant administration of itraconazole. The patient had enrolled in a community methadone substitution program 9 months earlier and was receiving 120 mg/day of methadone; she claimed to be heroin-free for the past 4 months. She presented with chest discomfort and syncope after receiving itraconazole (2 doses of 200 mg) for vaginal thrush. She had no known history of cardiac, respiratory, hepatic, or neurological disease. ECG monitoring showed sinus rhythm with QT interval prolongation (520 msec) and torsade de pointes, which resolved spontaneously. Blood work showed normal serum electrolytes, blood counts, liver and renal function, and cardiac enzymes. Methadone was switched to buprenorphine, and potassium and magnesium supplements were prescribed. The patient's cardiovascular status remained stable following methadone discontinuation and she was discharged on day 3 without further issue .
Methadone Overview
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Methadone is used to relieve severe pain in people who are expected to need pain medication around the clock for a long time and who cannot be treated with other medications. It also is used to prevent withdrawal symptoms in patients who were addicted to opiate drugs and are enrolled in treatment programs in order to stop taking or continue not taking the drugs. Methadone is in a class of medications called opiate (narcotic) analgesics. Methadone works to treat pain by changing the way the brain and nervous system respond to pain. It works to treat people who were addicted to opiate drugs by producing similar effects and preventing withdrawal symptoms in people who have stopped using these drugs.
Itraconazole Overview
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Itraconazole capsules (Sporanox, Tolsura) are used to treat fungal infections in the lungs that can spread throughout the body. Itraconazole capsules (Sporanox) are also used to treat fungal infections of the fingernails and toenails. Itraconazole oral solution (liquid) is used to treat yeast infections of the mouth and throat or of the esophagus (tube that connects the throat to the stomach). Itraconazole is in a class of antifungals called triazoles. It works by slowing the growth of fungi that cause infection.
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Definitions
Severity Categories
Contraindicated
These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.
Major
This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.
Moderate
This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.
Minor
While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.
Onset
Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.
Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.
Evidence
Level of documentation of the interaction.
Established: The interaction is documented and substantiated in peer-reviewed medical literature.
Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.
How To Manage The Interaction
Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.
It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.
Mechanism Of Interaction
The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.
Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.
Where Does Our Information Come From?
Information for our drug interactions is compiled from several drug compendia, including:
The prescribing information for each drug, as published on DailyMED, is also used.
Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.
The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.