Updated: Jul 25, 2020
sildenafil, vardenafil, tadalafil
-30 to 60 minutes prior to the event. Stimulation is required for efficacy.
-Do not exceed 1 tablet per day
Duration of Action:
-Tadalafil has a very long duration of action (up to 72 hours) compared to sildenafil and vardenafil (4 hours)
-Visual disturbances such as blurry vision
-Priapism - erection which does not resolve within four hours **may need medical attention
-Do not combine with nitrates - could lead to fatal hypotension. Make sure to space nitrate after 24 hours for sildenafil or vardenafil, and 48 hours for tadalafil.
-alpha blockers and antihypertensives: dizziness and hypotension
-CYP 3A4 inhibitors such as ketoconazole since PDE5 inhibitors are substrates