Olicard Retard (Isosorbide Mononitrate)

Isosorbide Mononitrate is used in the management of angina‑related conditions, acting on the coronary circulation to reduce myocardial oxygen demand.

• Chronic stable angina: reduces frequency of angina attacks and improves exercise tolerance.
• Variant (Prinzmetal) angina: prevents episodic coronary spasm and associated chest pain.
• Post‑myocardial infarction prophylaxis: helps lower risk of recurrent angina episodes during recovery.

• Isosorbide mononitrate is metabolized to nitric oxide, which activates guanylate cyclase in vascular smooth‑muscle cells. The resulting rise in cyclic GMP causes relaxation of arterial and venous smooth muscle, producing vasodilation that reduces preload and afterload, thereby decreasing myocardial oxygen consumption and alleviating angina.

Adverse reactions may occur with any nitrate therapy.

Common Side Effects

• Headache: mild to moderate, often transient.
• Flushing: warmth and redness of the skin, especially face.
• Dizziness or light‑headedness, particularly on standing.
• Nausea or upset stomach.
• Palpitations: sensation of rapid or irregular heartbeat.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure causing fainting.
• Methemoglobinemia: abnormal hemoglobin that impairs oxygen delivery.
• Allergic reactions: rash, itching, swelling, or difficulty breathing.
• Syncope: sudden loss of consciousness unrelated to posture.

Before initiating therapy, clinicians should evaluate cardiovascular status and concomitant medications.

• Assess blood pressure: avoid use in patients with uncontrolled hypotension.
• Review cardiac history: caution in recent myocardial infarction or severe heart failure.
• Evaluate liver and renal function: dose may need adjustment in impairment.
• Avoid concurrent use of phosphodiesterase‑5 inhibitors: risk of profound hypotension.
• Counsel on orthostatic changes: rise slowly from sitting or lying positions.
• Store at ambient temperature: keep below 25°C in the original container, protected from moisture.

Isosorbide mononitrate interacts with several drug classes; careful monitoring is advised.

Major Interactions (Avoid)

• Sildenafil, tadalafil, vardenafil: combined vasodilatory effect can cause severe hypotension.
• Other nitrates (e.g., nitroglycerin): additive blood‑pressure lowering effect.

Moderate Interactions (Monitor Closely)

• Antihypertensives (ACE inhibitors, ARBs, beta‑blockers): may enhance blood‑pressure reduction.
• Diuretics: increase risk of electrolyte imbalance and hypotension.
• Alcohol: can potentiate vasodilatory response and dizziness.