Monopril (Fosinopril Sodium)

Monopril (fosinopril) is an ACE inhibitor used in cardiovascular disease management.

• Hypertension: lowers systemic blood pressure by reducing angiotensin II‑mediated vasoconstriction.
• Heart failure: improves ventricular function and reduces symptoms such as dyspnea and edema.
• Post‑myocardial infarction: decreases the risk of subsequent cardiovascular events and supports cardiac remodeling.

• Fosinopril is converted in vivo to its active form, fosinoprilat, which binds to the active site of angiotensin‑converting enzyme (ACE). This inhibition prevents the conversion of angiotensin I to the potent vasoconstrictor angiotensin II, leading to vasodilation, reduced aldosterone secretion, and decreased sodium and water retention, thereby lowering blood pressure and easing cardiac workload.

Fosinopril may cause a range of adverse reactions, which are grouped by frequency.

Common Side Effects

• Cough: persistent dry cough in many patients.
• Dizziness: especially upon standing or dose changes.
• Headache: mild to moderate intensity.
• Fatigue: general feeling of tiredness.
• Nausea: occasional upset stomach.
• Taste disturbance: altered or metallic taste.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips, tongue, or airway requiring immediate medical attention.
• Severe hypotension: marked drop in blood pressure, potentially causing fainting.
• Renal impairment: sudden rise in serum creatinine or reduced kidney function.
• Hepatotoxicity: elevated liver enzymes indicating liver injury.
• Anaphylactoid reactions: rare severe allergic responses.

When prescribing Monopril, clinicians should observe several precautionary measures to ensure patient safety.

• Blood pressure monitoring: check regularly after initiation and dose adjustments.
• Renal function assessment: evaluate serum creatinine and eGFR before and during therapy.
• Serum potassium monitoring: avoid hyperkalaemia, especially with potassium‑sparing agents.
• Pregnancy contraindication: avoid use during pregnancy due to potential fetal harm.
• Dose adjustment in hepatic impairment: use lower initial doses and titrate cautiously.
• Store at room temperature: keep in original container, protect from moisture and light.

Fosinopril can interact with other medicines, requiring attention to avoid reduced efficacy or increased toxicity.

Major Interactions (Avoid)

• Aliskiren (in diabetic patients): combined use may increase risk of renal impairment, hyperkalaemia, and hypotension.
• Lithium: fosinopril may raise lithium levels, leading to toxicity.
• Potassium‑sparing diuretics (e.g., spironolactone): risk of severe hyperkalaemia.

Moderate Interactions (Monitor Closely)

• NSAIDs (e.g., ibuprofen): may blunt antihypertensive effect and impair renal function.
• Thiazide diuretics: additive blood‑pressure lowering effect; monitor for hypotension.