Viagra, or sildenafil, primarily works by inhibiting phosphodiesterase-5 (PDE5). This enzyme breaks down cyclic guanosine monophosphate (cGMP), a molecule crucial for smooth muscle relaxation. By blocking PDE5, Viagra increases cGMP levels, leading to vasodilation, particularly in the corpus cavernosum, facilitating penile erection. This vasodilation also affects other blood vessels.
Regarding blood pressure, Viagra’s impact is generally mild but can be significant in individuals with pre-existing conditions. It can cause a modest decrease in blood pressure, typically ranging from 2-8 mmHg systolic and 1-5 mmHg diastolic. This effect is usually more pronounced when Viagra is combined with nitrates, medications commonly used to treat angina. Combining these drugs can trigger a dangerous drop in blood pressure, potentially leading to serious cardiovascular events. Therefore, avoid concurrent use.
Patients with unstable angina or severe cardiovascular disease should exercise extreme caution. Their physicians should carefully assess the risks before prescribing Viagra. Blood pressure monitoring might be recommended before, during, and after treatment, particularly for individuals with hypertension or hypotension.
In summary: Viagra’s mechanism involves vasodilation; it can moderately lower blood pressure; and combining it with nitrates is dangerous. Consult your doctor for a comprehensive assessment before using Viagra.