Lekap (Sildenafil)

• Sildenafil acts on the phosphodiesterase type 5 pathway, addressing conditions related to vascular smooth‑muscle tone and blood flow regulation.
• Erectile dysfunction: improves the ability to achieve and maintain an erection sufficient for satisfactory sexual activity by enhancing blood flow to the corpus cavernosum.
• Pulmonary arterial hypertension: enhances exercise capacity and reduces pulmonary arterial pressure by promoting vasodilation in the pulmonary vasculature, thereby improving hemodynamics.
• Male sexual dysfunction: supports overall sexual performance in men with vascular‑related erectile issues by increasing penile blood flow.

• Sildenafil selectively inhibits the enzyme phosphodiesterase type 5 (PDE5) found in smooth‑muscle cells of the corpus cavernosum and pulmonary vasculature. By blocking PDE5, it prevents the breakdown of cyclic guanosine monophosphate (cGMP), allowing cGMP to accumulate. Elevated cGMP leads to relaxation of smooth muscle and vasodilation, which enhances blood flow to the penis during sexual stimulation and reduces pulmonary arterial pressure.

Sildenafil may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Headache: mild to moderate headache.
• Flushing: warmth and redness of the face or upper chest.
• Dyspepsia: indigestion or upset stomach.
• Nasal congestion: stuffy nose.
• Back pain: aching discomfort in the lower back.
• Dizziness: sensation of light‑headedness or unsteadiness.

Serious or Rare Side Effects

• Priapism: prolonged erection lasting more than four hours requiring medical attention.
• Sudden vision loss: abrupt loss of vision in one or both eyes, possibly indicating non‑arteritic anterior ischemic optic neuropathy.
• Sudden hearing loss: rapid decrease or loss of hearing, sometimes accompanied by tinnitus.
• Myocardial infarction: heart attack symptoms such as chest pain or pressure.
• Stroke: neurological deficits including sudden weakness, speech difficulty, or facial droop.

Before prescribing Lekap, clinicians should consider several safety factors.

• Cardiovascular assessment: evaluate recent heart conditions before prescribing.
• Concomitant nitrate use: avoid co‑administration due to risk of severe hypotension.
• Visual disturbances: monitor patients with retinal disorders.
• Hearing changes: advise patients to report sudden hearing loss.
• Dosage adjustment: consider renal or hepatic impairment when determining dose.
• Store at ambient temperature: keep tablets in original packaging, protect from moisture and direct light.

Sildenafil can interact with other medicines, requiring careful management.

Major Interactions (Avoid)

• Nitrates (e.g., nitroglycerin): may cause profound hypotension.
• Nitric oxide donors (e.g., amyl nitrite): risk of severe blood pressure drop.
• Riociguat: combined vasodilatory effect can be dangerous.

Moderate Interactions (Monitor Closely)

• Alpha‑blockers (e.g., doxazosin): may cause additive blood pressure lowering.
• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): increase sildenafil plasma levels.
• CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce efficacy.