There are no specifically mentioned DDIs in the Endocrine Society Clinical Practice Guidelines or the AACE Hypogonadism Guidelines regarding ARV drugs and treatment for hypogonadism in male patients.
Phosphodiesterase (PDE)-5 inhibitors prescribed for erectile dysfunction are metabolized via the same enzyme (CYP3A4) in the liver as many ARV therapies. Therefore, co-administration may lead to elevated levels of PDE-5 inhibitor in the blood,1,2 so dose reduction/modification of the PDE-5 inhibitor may be required.
Potential DDIs may occur if sildenafil is co-administered with PIs or NNRTIs.3
Physicians should be aware of potential DDIs when planning to use specific medication combinations. There are a number of online resources for assessment of DDIs: one such tool is the HIV drug interactions website.
Merry C, Barry MG, Ryan M, et al. Interaction of sildenafil and indinavir when co-administered to HIV-positive patients. AIDS. 1999;13:101–107.
Muirhead GJ, Wulff MB, Fielding A, et al. Pharmacokinetic interactions between sildenafil and saquinavir / ritonavir. Br J Clin Pharmacol. 2000;50:99–107.
HIV drug interactions. The Liverpool HIV Pharmacology Group (LHPG) Accessed 13 February 2012.