Drug interactions between Adapin and atazanavir
| Results for the following 2 drugs: |
|---|
| Adapin (doxepin) |
| atazanavir |
Interactions between your selected drugs
doxepin ↔ atazanavir
Applies to:Adapin (doxepin) and atazanavir
MONITOR: Product labeling for certain protease inhibitors (PIs) such as amprenavir and atazanavir states that serious and/or life-threatening drug interactions may occur with tricyclic antidepressants (TCAs), presumably due to PI inhibition of TCA metabolism via CYP450 3A4. High plasma levels of TCAs could conceivably lead to serious adverse reactions including QT interval prolongation and ventricular arrhythmias such as ventricular tachycardia and torsade de pointes. However, the clinical significance of such an interaction is unknown, as it has not been studied and there are no case reports of it published in the medical literature. Moreover, many TCAs are thought to be substrates of multiple CYP450 isoenzymes, thus the effects of CYP450 3A4 inhibition alone are unknown. Some TCAs such as desipramine, doxepin, and nortriptyline are also thought to be primarily metabolized by CYP450 2D6, which is not known to be inhibited by most PIs (except ritonavir) to any significant extent.
MANAGEMENT: Until further information is available, caution is advised if protease inhibitors must be used with certain TCAs. Pharmacologic response and plasma TCA levels should be monitored more closely whenever a PI is added to or withdrawn from therapy, and the TCA dosage adjusted as necessary.
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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