SILDENAFIL

Sildenafil is a medication used primarily to treat erectile dysfunction (ED) and pulmonary arterial hypertension (PAH). It works by inhibiting phosphodiesterase type 5 (PDE5), an enzyme that regulates blood flow in the penis and lungs.

Indications

-Erectile Dysfunction (ED) -Pulmonary Arterial Hypertension (PAH)

Dosage

-Erectile Dysfunction: Initial dose: 50 mg taken as needed approximately 1 hour before sexual activity. Maintenance dose: 25 to 100 mg taken as needed, based on efficacy and tolerability. Maximum recommended dosing frequency is once per day. -Pulmonary Arterial Hypertension: 20 mg three times a day, taken approximately 4 to 6 hours apart.

Contra-Indications

-Concurrent use of nitrates or nitric oxide donors (e.g., nitroglycerin) due to the risk of severe hypotension. -Severe cardiovascular conditions or recent history of heart attack or stroke. -Known hypersensitivity to sildenafil or any component of the tablet. -Severe liver impairment. -Severe hypotension (blood pressure less than 90/50 mmHg).

Special Precautions

-Use with caution in patients with cardiovascular disease. -Patients with a predisposition to priapism (e.g., sickle cell anemia, multiple myeloma, or leukemia). -Renal and hepatic impairment may require dosage adjustments. -Should not be used with other treatments for ED without consulting a healthcare provider. -Caution in patients with retinitis pigmentosa, as there is limited clinical safety information available.

Side Effects

-Common: Headache, flushing, dyspepsia, nasal congestion, dizziness, and visual disturbances (such as changes in color vision or blurred vision). -Rare: Non-arteritic anterior ischemic optic neuropathy (NAION), sudden hearing loss, priapism (prolonged and painful erection).

Drug Interactions

-Nitrates: Significant risk of hypotension. -Alpha-blockers: Increased risk of symptomatic hypotension. -CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir): Increased sildenafil levels. -CYP3A4 inducers (e.g., rifampicin): Reduced efficacy of sildenafil. -Other ED treatments: Increased risk of adverse effects and lack of efficacy data.