Drug interactions between Cerebyx and Methadose
| Results for the following 2 drugs: |
|---|
| Cerebyx (fosphenytoin) |
| Methadose (methadone) |
Interactions between your selected drugs
methadone ↔ fosphenytoin
Applies to:Methadose (methadone) and Cerebyx (fosphenytoin)
MONITOR: The coadministration with phenytoin may decrease the plasma concentrations and pharmacologic effects of methadone. The mechanism is phenytoin induction of CYP450 3A4, the isoenzyme responsible for the metabolic clearance of methadone. There have been case reports of patients receiving methadone maintenance treatment who developed withdrawal symptoms several days following the addition of phenytoin. Fosphenytoin is also expected to cause this interaction if used for more than 2 or 3 days, since it is rapidly metabolized in vivo to phenytoin.
MANAGEMENT: Patients treated concomitantly with phenytoin may require a higher dosage of methadone to control pain or withdrawal symptoms. Pharmacologic response to methadone should be monitored more closely whenever phenytoin is added to or withdrawn from therapy in patients stabilized on their methadone regimen, and the dosage adjusted as necessary. Patients should be advised to notify their caregiver if they experience possible symptoms of methadone withdrawal, including 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.
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