Drug interactions between atazanavir and Levitra
| Results for the following 2 drugs: |
|---|
| atazanavir |
| Levitra (vardenafil) |
Interactions between your selected drugs
atazanavir ↔ vardenafil
Applies to:atazanavir and Levitra (vardenafil)
ADJUST DOSE: Coadministration with atazanavir may increase the plasma concentrations of vardenafil. The proposed mechanism is atazanavir inhibition of CYP450 3A4, the isoenzyme primarily responsible for the metabolic clearance of vardenafil. The interaction has not been specifically studied but is presumed based on data available for ritonavir, another protease inhibitor. According to vardenafil labeling, coadministration of ritonavir (600 mg twice a day) and vardenafil (5 mg) resulted in a 13-fold increase in the peak plasma concentration (Cmax) and a 49-fold increase in the area under the concentration-time curve (AUC) of vardenafil. The half-life of vardenafil, normally 4 to 5 hours, was significantly prolonged to 26 hours. To what extent this interaction may occur with atazanavir is unknown, as it is a considerably weaker inhibitor of CYP450 3A4 than ritonavir.
MANAGEMENT: Atazanavir labeling states that patients treated with atazanavir should not receive more than a single 2.5 mg dose of vardenafil within a 72-hour period. Patients should be advised to promptly notify their physician if they experience pain or tightness in the chest or jaw, irregular heartbeat, nausea, shortness of breath, visual disturbances, syncope, or prolonged erection (greater than 4 hours).
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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