Protease inhibitors Alfentanil

Drugs that may affect fluconazole include cimetidine, hydrochlorothiazide, and rifampin. Drugs that may be affected by fluconazole include alfentanil, benzodiazepines, buspirone, carbamazepine, cisapride, oral contraceptives, corticosteroids, cyclosporine, haloperidol, HMG-CoA reductase inhibitors, losartan, nisoldipine, phenytoin, protease inhibitors, rifabutin, sirolimus, sulfonylureas, tacrolimus, theophylline, tolterodine, tricyclic antidepressants, vinca alkaloids, warfarin, zidovudine, and zolpidem. 

ALFENTANIL, BUPRENORPHINE, FENTANYL, TRAMADOL PROTEASE INHIBITORS Possibly t adverse effects when buprenorphine is co administered with indinavir, ritonavir (with or without lopinavir) or saquinavir Inhibition of CYP3A4 (CYP2D6 in the case of tramadol) Halve the starting dose and titrate to effect. For single injection of fentanyl, monitor sedation and respiratoiy function closely. If continued use of fentanyl, i dose may be required. Concomitant use of ritonavir and transdermal fentanyl is not recommended... 

The CYP3A4 isozyme is responsible for the metabolism of a large number of endogenous compounds as well as a wide range of drugs (50). Fentanyl, alfentanil, and sufentanil are substrates for CYP3A4, and therefore drugs that inhibit this enzyme, such as erythromycin, HIV protease inhibitors, or cimetidine. 

Ritonavir markedly increases the levels of fentanyl, and markedly increases alfentanil-induced miosis. Other protease inhibitors such as nelfinavir may have a similar effect Care should also be taken if ritonavir is used with other protease inhibitors as a pharmacokinetic enhancer. 

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