Abstract

Srinivas Pentyala,*, Aleef Rahman, Supriya Mishra, Sowmya Muthiki, EmilyHughes, Abhishek Bikkani, Kathleen Cervo, Christopher Maruso and Sardar Khan

Novel drugs for Erectile Dysfunction (ED) must be assessed for their interactions with other already approved medications that are processed through similar metabolic pathways. The cytochrome P450 enzyme family, in particular 3A4 isoform, is ubiquitously used to oxidize azole antifungals, erythromycin, and HIV protease inhibitors. Administering multiple medications using cytochrome P450 CYP3A4 (3A4) as a primary metabolic route may cause unexpected toxicological effects in patients. Current U.S Food and Drug Administration (FDA) approved ED drugs such as sildenafil (Viagra), tadalafil (Levitra), and vardenafil (Cialis), all Phosphodiesterase-5 inhibitors, are also metabolized by 3A4. The overlapping metabolic pathways for the above mentioned PDE-5 inhibitors are known, however it is still imperative to discover any negative clinical manifestations that may arise from their concomitant use or their use with other substrates that are metabolized by 3A4 enzyme. Worldwide, approximately 150 million men are struggling with ED, making this research a valid obligation. Consequently, interaction of the widely prescribed ED drugs and their interactions with 3A4 enzyme are discussed in this review.