PI Perspective 25: Sildenafil (Viagra®) Drug Interactions

PI Perspective 25: Sildenafil (Viagra®) Drug Interactions

Project Inform - September, 1998

The recently approved drug, sildenafil citrate (Viagra®), for erectile dysfunction (impotence) should not be used by people who are using organic nitrates in any form, including 'poppers' and certain drugs taken to decrease high blood pressure. Sildenafil can increase the hypotensive (lowering of blood pressure) effects of nitrates which could be fatal. The protease inhibitors and delavirdine (Rescriptor®) will likely increase sildenafil levels while nevirapine (Viramune®) and efavirenz (Sustiva®) will likely decrease sildenafil levels. People taking either a protease inhibitor or delavirdine and are thinking of starting sildenafil should consider using a 25mg dose, since using a higher dose may increase sildenafil's effectiveness and the incidence of side effects. Other drugs commonly used by people with HIV can also affect sildenafil levels. Ketoconazole and itraconazole will likely significantly increase sildenafil levels while rifampin and rifabutin are expected to decrease sildenafil levels in blood.

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Always watch for outdated information. This article first appeared in 1998. This material is designed to support, not replace, the relationship that exists between you and your doctor.

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Project Inform, established in 1985 as a national, non profit, community-based HIV/AIDS treatment information and advocacy organization, serves HIV-infected individuals, their care-givers, and their healthcare and service providers through its national, toll-free treatment hotline, the PI Perspective and other information publications, educational Town Meetings, on-line services and research and drug access advocacy programs. All information is available free of charge; donations are strongly encouraged. For more information, contact the Project Inform National HIV/AIDS Treatment Hotline. Email: web@projinf.org; Website: http://www.projinf.org.

The original of this article can be found at http://www.projinf.org/pub/25/resistanthiv.html

This information is designed to support, not replace, the relationship that exists between you and your doctor.
©1998. AEGiS.