Olvion (Sildenafil)

Sildenafil acts on the nitric‑oxide/cGMP pathway to improve blood flow in conditions where vascular relaxation is therapeutic.

• 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 Raynaud’s phenomenon: reduces frequency and severity of vasospastic attacks.

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

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

Common Side Effects

• Headache
• Flushing
• Dyspepsia
• Nasal congestion
• Visual disturbances (blurred vision, colour tinge)
• Myalgia

Serious or Rare Side Effects

• Sudden loss of vision (non‑arteritic anterior ischemic optic neuropathy)
• Sudden hearing loss
• Prolonged erection lasting more than 4 hours (priapism)
• Severe hypotension
• Cardiac arrhythmia

When using Sildenafil, certain precautions should be observed to ensure safe and effective therapy.

• Cardiovascular assessment: evaluate underlying heart disease before initiating therapy.
• Concomitant nitrate use: avoid due to risk of severe hypotension.
• Visual disorders: discontinue if sudden vision loss occurs.
• Hearing changes: monitor for sudden hearing loss.
• Drug interactions: review all concurrent medications for potential interactions.
• Store at ambient temperature: keep below 25°C in the original packaging, protect from moisture and direct sunlight.

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

Major Interactions (Avoid)

• Nitrates (e.g., nitroglycerin): may cause profound hypotension.
• Guanylate cyclase stimulators (e.g., riociguat): risk of excessive vasodilation.
• Potent CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): increase sildenafil exposure.

Moderate Interactions (Monitor Closely)

• Alpha‑blockers: may enhance blood pressure lowering effects.
• Antihypertensives: additive hypotensive effect possible.
• Protease inhibitors (e.g., ritonavir): may raise plasma levels modestly.