Monopril (Fosinopril Sodium)

• Monopril (fosinopril) acts on the renin‑angiotensin system to lower blood pressure and improve cardiac function.
• Hypertension: reduces systolic and diastolic pressure, decreasing cardiovascular strain.
• Heart failure: improves ventricular performance and lessens symptoms such as dyspnea and edema.
• Post‑myocardial infarction: helps lower mortality risk by attenuating adverse cardiac remodeling.

• Fosinopril is a prodrug that is converted in the liver to the active metabolite fosinoprilat. The metabolite binds to the active site of angiotensin‑converting enzyme, blocking the conversion of angiotensin I to the vasoconstrictor angiotensin II and decreasing aldosterone secretion. This results in vasodilation, reduced peripheral resistance and lowered blood pressure.

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

Common Side Effects

• Cough: dry, persistent cough often reported early in therapy.
• Dizziness: light‑headedness, especially after the first dose or dose increase.
• Headache: mild to moderate intensity.
• Fatigue: general tiredness without exertion.
• Hypotension: symptomatic low blood pressure, particularly in volume‑depleted patients.
• Taste disturbance: altered or metallic taste.

Serious or Rare Side Effects

• Angioedema: swelling of lips, tongue or airway requiring immediate medical attention.
• Severe hypotension: marked drop in blood pressure leading to fainting or shock.
• Renal impairment: worsening kidney function, indicated by rising creatinine.
• Hepatic enzyme elevation: significant increase in liver transaminases.
• Neutropenia: marked reduction in white blood cells increasing infection risk.
• Anaphylactoid reaction: severe allergic response with rash and respiratory distress.

When prescribing or dispensing Monopril, several precautionary measures should be observed.

• Monitor blood pressure: check regularly to avoid excessive hypotension.
• Assess renal function: evaluate serum creatinine and eGFR before and during therapy.
• Check electrolytes: especially potassium levels to prevent hyperkalaemia.
• Use caution in pregnancy: limited data; avoid unless benefits outweigh risks.
• Avoid in patients with prior angioedema: history of swelling related to ACE inhibitors contraindicates use.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Fosinopril can interact with other medicines, influencing its efficacy or safety.

Major Interactions (Avoid)

• Aliskiren: combined use may increase risk of renal dysfunction and hyperkalaemia.
• Lithium: fosinopril can raise lithium concentrations, leading to toxicity.
• Potassium‑sparing diuretics: concurrent use may cause dangerous hyperkalaemia.

Moderate Interactions (Monitor Closely)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): may blunt antihypertensive effect and affect kidney function.
• Diuretics: may enhance hypotensive response; monitor blood pressure and electrolytes.