Olvion (Sildenafil)

Sildenafil acts on the nitric‑oxide/cGMP pathway to facilitate erections in men with erectile dysfunction.

• Erectile dysfunction: improves ability to achieve and maintain an erection suitable for sexual activity.
• Pulmonary arterial hypertension: lowers pulmonary arterial pressure and improves exercise capacity.
• Secondary use in benign prostatic hyperplasia (off‑label): may relieve lower urinary tract symptoms associated with BPH.

• Sildenafil selectively inhibits the enzyme phosphodiesterase type 5, preventing the breakdown of cyclic guanosine monophosphate (cG5). Elevated cGMP levels lead to smooth‑muscle relaxation in the corpus cavernosum and pulmonary vasculature, enhancing blood flow when sexual stimulation or pulmonary vascular stress is present.

Sildenafil may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Headache: mild to moderate headache occurring shortly after dosing.
• Flushing: warm sensation and reddening of the face or neck.
• Dyspepsia: indigestion or upset stomach.
• Nasal congestion: feeling of a blocked nose.
• Visual disturbances: blurred vision or changes in colour perception.
• Myalgia: muscle aches, particularly after physical activity.

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 (non‑arteritic anterior ischemic optic neuropathy).
• Sudden hearing loss: rapid decrease or loss of hearing.
• Cardiovascular events: chest pain, arrhythmia or myocardial infarction in susceptible individuals.
• Severe hypotension: marked drop in blood pressure, especially when combined with nitrates.

Before initiating therapy with Sildenafil, patients should be evaluated for cardiovascular health and concomitant medication use.

• Cardiovascular assessment: ensure stable heart condition before use.
• Nitrate use: avoid concomitant use with nitrates or nitric oxide donors.
• Alpha‑blockers: use with caution; monitor blood pressure.
• Visual disorders: avoid if you have retinitis pigmentosa or recent non‑arteritic anterior ischemic optic neuropathy.
• Hepatic or renal impairment: dose may need adjustment; consult prescriber.
• Store at below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Sildenafil can interact with several drug classes, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Nitrates: concurrent use can cause severe hypotension.
• Guanylate cyclase stimulators: may lead to excessive vasodilation.
• Certain antifungals (ketoconazole, itraconazole): increase sildenafil plasma levels.

Moderate Interactions (Monitor Closely)

• Alpha‑blockers: may cause additive blood‑pressure lowering effects.
• Antihypertensives: monitor for enhanced hypotensive response.
• CYP3A4 inhibitors (e.g., erythromycin, HIV protease inhibitors): may modestly raise sildenafil concentrations.