Which class of drugs is first-line therapy for erectile dysfunction?

• A. Penile implants
• B. Sildenafil, tadalafil, vardenafil
• C. Dopamine agonists
• D. Topical nitroglycerin

Answer: (B)

Oral phosphodiesterase-5 inhibitors are the preferred first-line therapy for erectile dysfunction. They boost the normal erectile response by blocking PDE-5, which normally degrades cGMP in the penile smooth muscle. When sexual stimulation triggers nitric oxide release, cGMP levels rise, causing smooth muscle relaxation, increased blood flow, and an erection. Drugs in this class—such as sildenafil, tadalafil, and vardenafil—are convenient, effective for many men, and noninvasive compared with surgical options. They must be taken with sexual arousal and are generally well tolerated, but can cause headache, facial flushing, indigestion, and nasal congestion. A key safety point is that they are contraindicated with nitrates because of the risk of dangerous hypotension, and they require caution when used with alpha-blockers or other cardiovascular medicines. Penile implants are reserved for cases that don’t respond to medical therapy, making them not first-line. Dopamine agonists or topical nitroglycerin aren’t standard first-line treatments for erectile dysfunction and do not address the underlying NO–cGMP pathway in the same reliable, evidence-based way.