Isdn 60 Retard (Isosorbide Dinitrate)

Isosorbide dinitrate is an organic nitrate used to manage coronary artery disease and heart failure.

• Angina pectoris: reduces frequency and severity of chest pain by decreasing myocardial oxygen demand.
• Chronic heart failure: improves exercise tolerance and symptoms by lowering preload and afterload.
• Stress‑test induced angina: prevents ischemic episodes during diagnostic exercise testing.

• Isosorbide dinitrate is metabolized to release nitric oxide, which activates guanylate cyclase in vascular smooth muscle. The resulting increase in cyclic GMP causes relaxation of arterial and venous walls, producing vasodilation, reduced preload and afterload, and a lower myocardial oxygen requirement, thereby alleviating ischemic chest pain.

Isosorbide dinitrate may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Headache
• Dizziness or light‑headedness
• Flushing
• Low blood pressure (hypotension)
• Nausea

Serious or Rare Side Effects

• Severe hypotension leading to syncope
• Myocardial infarction in susceptible patients
• Allergic reactions such as rash or anaphylaxis
• Methemoglobinemia (rare)
• Vision disturbances

When prescribing Isosorbide dinitrate, clinicians should observe several precautionary measures to ensure safe use.

• Dose titration: start with the lowest effective dose and increase gradually under medical supervision.
• Concomitant PDE‑5 inhibitors: avoid use with sildenafil, tadalafil or similar agents due to risk of profound hypotension.
• Blood pressure monitoring: check blood pressure regularly, especially after dose adjustments.
• Tolerance development: assess for reduced efficacy over time and consider drug‑free intervals if needed.
• Hepatic or renal impairment: use with caution and adjust dosing as appropriate.
• Store at room temperature: keep in the original container, protect from moisture and heat.

Isosorbide dinitrate can interact with several medicines, altering its effect or increasing adverse reactions.

Major Interactions (Avoid)

• Sildenafil, tadalafil, vardenafil (PDE‑5 inhibitors): may cause severe hypotension.
• Other nitrates (nitroglycerin, isosorbide mononitrate): additive vasodilatory effect leading to dangerous blood pressure drop.
• Sodium nitroprusside: excessive vasodilation and hypotension.

Moderate Interactions (Monitor Closely)

• Antihypertensives (ACE inhibitors, beta‑blockers, calcium channel blockers): may enhance blood‑pressure‑lowering effect.
• Diuretics: can increase volume depletion and orthostatic hypotension.
• Alcohol: may potentiate hypotensive response.