Urologicals treat urinary tract dysfunctions and erectile dysfunction. Phosphodiesterase-5 (PDE5) inhibitors — sildenafil (Viagra®, Revatio®), tadalafil (Cialis®) and vardenafil (Levitra®) — selectively inhibit PDE5 in the corpus cavernous smooth muscle, potentiating GMPc effect and promoting vasodilation. Used in erectile dysfunction and, sildenafil and tadalafil, also in pulmonary arterial hypertension (PAH). Contraindicated in patients taking nitrates (risk of severe hypotension). (Sources: DailyMed/FDA, EMC-UK/MHRA)
