Sildenafil selectively inhibits phosphodiesterase type 5 (PDE5), an enzyme that breaks down cyclic guanosine monophosphate (cGMP). Higher cGMP levels relax smooth muscle in the penis, increasing blood flow.
Specifically, during sexual stimulation, nitric oxide (NO) is released. NO activates guanylate cyclase, which then produces cGMP. This cGMP causes relaxation of penile smooth muscles, leading to vasodilation and an erection. By inhibiting PDE5, sildenafil prolongs the effects of cGMP, enhancing and sustaining this vasodilation.
This mechanism explains why sildenafil is only effective with sexual stimulation; it doesn’t directly cause erections. The drug facilitates the natural process by improving the body’s response to sexual stimuli.
Remember, individual responses to sildenafil vary. Factors like age, overall health, and other medications can influence its efficacy.
Consult your doctor before using sildenafil to discuss potential side effects and interactions with your existing medications. They can help determine the appropriate dosage and ensure safe use.
