Sildenafil Citrate

Phosphodiesterase-5 inhibitor for pulmonary hypertension in horses and small animals; pulmonary vasodilation. PDE5 inhibitor (sildenafil citrate). Mechanism: inhibits phosphodiesterase type 5 (PDE5) → prevents cGMP degradation → sustained NO-mediated smooth muscle relaxation → pulmonary vasodilation (selective for pulmonary vasculature). Reduces pulmonary arterial pressure and vascular resistance. Oral or compounded preparations. Key information PDE5 inhibitor — pulmonary hypertension. Store at room temperature. Drug interactions: do NOT use with nitrates. Monitor blood pressure. Administer consistently.

Oral tablets: Administer orally. May be given with food to improve compliance and reduce GI upset. Administer with food to reduce GI adverse effects. or without. Administer 3 times daily at consistent intervals. Store at room temperature; protect from light. If a dose is missed Give the missed dose as soon as you remember. If the next dose is due within a few hours, skip the missed dose and resume the regular schedule. Never give a double dose.

Cardiovascular: hypotension, flushing. GI: vomiting, diarrhea. CNS: headache equivalent. Vision changes (phosphodiesterase in retinal photoreceptors). Penile erection (priapism — rare). Interaction with nitrates (severe hypotension — contraindicated).

For animals Use with caution in hepatic impairment. Drug interaction: CONTRAINDICATED with nitrates (severe hypotension). Monitor blood pressure and clinical response. Not approved for use in food-producing animals. Use with caution in pregnant animals. For people handling this medication Wash hands thoroughly with soap and water after handling. Avoid contact with eyes; if contact occurs, flush with water for 15 minutes and seek medical attention. Keep out of reach of children. If accidental ingestion occurs, contact Poison Control (1-800-222-1222). PDE5 inhibitor — keep out of reach of children. Dangerous hypotension if combined with nitrates. Wash hands thoroughly with soap and water after handling.

Contact your veterinarian. Sildenafil overdose causes severe low blood pressure, flushing, and cardiovascular effects. Emergency supportive care required.