Methadone Drug Interactions
Methadone Drug Interactions Explained
The following sections explain in detail the potentially negative interactions that can occur when methadone is combined with any of the drugs listed above.
CYP 3A4 Inducer Medications
Methadone is metabolized in the body by certain enzymes in the liver known as CYP 3A4 enzymes. Medications known as CYP 3A4 inducers make these enzymes work quicker than normal and might cause methadone to be metabolized more quickly, which might decrease its effectiveness or cause withdrawal symptoms. Check with your healthcare provider before combining methadone with a CYP 3A4 inducer.
CYP 3A4 Inhibitors Medications
Some medications cause the CYP 3A4 enzymes to work more slowly. This may cause methadone to be metabolized more slowly, increasing the level in the blood and, perhaps, increasing the risk of methadone side effects (including potentially dangerous ones). Check with your healthcare provider before taking methadone with a CYP 3A4 inhibitor.
It should be noted that some CYP 3A4 inhibitors (specifically, some protease inhibitor HIV medications) seem to produce the opposite effect, causing a decrease in methadone levels (see the protease inhibitor section of this article for more information).
Methadone may increase the level of desipramine in the blood, perhaps increasing the risk of side effects.
Methadone can decrease the level of didanosine in the blood, potentially making it less effective. Check with your healthcare provider before taking these medications together. Your healthcare provider may need to increase your didanosine dosage.
Medications That Cause QT Prolongation
Methadone can cause a potentially dangerous change in heart rhythm known as QT prolongation. Your healthcare provider should monitor your heart closely if you must take methadone with other medications that prolong the QT interval (see QT-Prolonging Medications).