What is a common first-line treatment for erectile dysfunction and its major contraindication?

• A. Vacuum erection devices
• B. PDE-5 inhibitors (e.g., sildenafil); contraindicated with nitrates
• C. Testosterone replacement
• D. Penile implants

Answer: (B)

The main concept here is how a common first-line therapy for erectile dysfunction works and why a certain drug interaction is dangerous. PDE-5 inhibitors, like sildenafil, are taken orally and work by boosting the nitric oxide–cGMP pathway that mediates erection. When a man is sexually aroused, nitric oxide is released and cyclic GMP causes smooth muscle relaxation in the penile arteries and the trabecular tissue, increasing blood flow into the penis and producing an erection. This class is widely used as the initial treatment because it is effective for many types of ED, easy to use, and has a favorable overall safety profile. It’s important to remember that sexual stimulation is still required for these meds to work; they do not cause an erection on their own.

The major contraindication is using these with nitrates (such as nitroglycerin or isosorbide dinitrate). Both drugs raise levels of cGMP, and combined use can lead to a dangerous drop in blood pressure, potentially causing fainting, heart complications, or worse. If a patient needs nitrates, a PDE-5 inhibitor should not be used. Other options exist, like vacuum devices, testosterone replacement, or penile implants, but they are not considered first-line in most cases and are typically used in specific scenarios or after trying PDE-5 inhibitors.