Monopril (Fosinopril Sodium)

• Fosinopril is an ACE‑inhibitor used in cardiovascular conditions that involve the renin‑angiotensin system.
• Hypertension: reduces systolic and diastolic blood pressure to target levels.
• Heart failure: improves symptoms and decreases hospitalisation risk.
• Post‑myocardial infarction: helps prevent adverse cardiac remodeling and reduces mortality.

• Fosinopril is a pro‑drug that is converted to fosinoprilat, which binds to the active site of angiotensin‑converting enzyme. This blocks the conversion of angiotensin I to the vasoconstrictor angiotensin II, leading to vasodilation, reduced aldosterone secretion, lower sodium‑water retention, and ultimately a decrease in arterial pressure.

Adverse reactions may vary in frequency and severity.

Common Side Effects

• Cough: dry, persistent throat irritation.
• Dizziness: especially on standing (orthostatic).
• Headache: mild to moderate intensity.
• Fatigue: general feeling of tiredness.
• Hyperkalemia: elevated blood potassium levels.
• Renal function changes: rise in serum creatinine.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips, tongue, or airway.
• Severe hypotension: marked drop in blood pressure.
• Acute renal failure: sudden loss of kidney function.
• Hepatotoxicity: liver enzyme elevations.
• Neutropenia: low white‑blood‑cell count.
• Stevens‑Johnson syndrome: severe skin reaction.

• Patients should be evaluated for specific risk factors before initiating therapy.
• Pregnancy: contraindicated in the second and third trimesters (Category D).
• Renal impairment: monitor kidney function and adjust dose if needed.
• Hyperkalemia: avoid concomitant potassium‑sparing agents.
• Hypotension: assess volume status, especially after diuretic use.
• Drug monitoring: regular blood pressure and laboratory checks are recommended.
• Store at ambient temperature: keep below 25 °C, retain in original container, protect from moisture and direct sunlight.

Fosinopril may interact with several drug classes, requiring clinical vigilance.

Major Interactions (Avoid)

• Aliskiren (in diabetic patients): risk of renal impairment and hyperkalemia.
• Lithium: increased lithium levels leading to toxicity.
• Potassium‑sparing diuretics or supplements: may cause dangerous hyperkalemia.

Moderate Interactions (Monitor Closely)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): may blunt antihypertensive effect and affect renal function.
• Diuretics: can potentiate hypotensive response, especially after first dose.
• Antihyperglycemics: ACE inhibitors may enhance glucose‑lowering effect.