Which drug class is used to treat erectile dysfunction?

• A. Anti-impotence
• B. Anti-infective
• C. Antimigraine
• D. Antiprotozoal

Answer: (A)

Erectile dysfunction is addressed by drugs that boost the body’s natural signaling for an erection. When sexually stimulated, nitric oxide releases in the penis and raises levels of cGMP, which relaxes smooth muscle and increases blood flow into the erectile tissues. The enzyme PDE5 normally breaks down cGMP, so blocking PDE5 keeps cGMP around longer, helping to achieve and maintain an erection in response to arousal. This mechanism is the hallmark of anti-impotence medications. They are not antibiotics, antimigraine drugs, or antiprotozoals, which treat infections, migraines, or protozoal infections, respectively. Examples include sildenafil and tadalafil. Side effects can include headache, flushing, and nasal congestion, and they must not be used with nitrates due to risky blood pressure drops.