Isosorbide Mononitrate Vitabalans (Isosorbide Mononitrate)

Isosorbide Mononitrate is a nitrate vasodilator used in the management of ischemic heart disease.

• Prevention of angina pectoris: reduces the frequency of angina attacks by improving myocardial oxygen supply.
• Chronic stable angina: provides long‑term symptom control and enhances exercise tolerance.
• Angina prophylaxis in coronary artery disease: maintains stable cardiac workload and limits ischemic episodes.

• Isosorbide Mononitrate acts as a nitric‑oxide donor. After oral absorption, it is metabolized to nitric oxide, which activates guanylate cyclase in vascular smooth muscle, increasing cyclic GMP levels. Elevated cGMP leads to relaxation of arterial and venous smooth muscle, producing vasodilation that lowers preload and afterload and improves myocardial oxygen delivery.

Adverse reactions may occur with any nitrate therapy.

Common Side Effects

• Headache: mild to moderate throbbing pain, often transient.
• Dizziness or light‑headedness: related to blood pressure lowering.
• Flushing: warm sensation and reddening of skin.
• Nausea: occasional gastrointestinal upset.
• Palpitations: awareness of heartbeat changes.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure requiring medical attention.
• Syncope: fainting episodes due to inadequate cerebral perfusion.
• Life‑threatening arrhythmias: rare but possible irregular heart rhythms.
• Allergic reactions: rash, itching, or swelling indicating hypersensitivity.
• Methemoglobinemia: rare blood disorder causing reduced oxygen transport.

Before initiating therapy, clinicians should evaluate patient-specific factors and monitor for potential complications.

• Assess cardiovascular status: check blood pressure and heart rate prior to starting treatment.
• Avoid concurrent PDE‑5 inhibitors: co‑administration may cause profound hypotension.
• Monitor for tolerance development: efficacy may diminish over time, requiring dose adjustment.
• Adjust dose in renal impairment: consider reduced dosing in patients with decreased renal function.
• Store at ambient temperature: keep below 25 °C, protect from moisture and light in the original container.

Isosorbide Mononitrate can interact with several drug classes; careful assessment is required.

Major Interactions (Avoid)

• Phosphodiesterase‑5 inhibitors (e.g., sildenafil): risk of severe hypotension.
• Other nitrates (e.g., nitroglycerin): additive vasodilatory effect leading to low blood pressure.
• Guanylate cyclase stimulators: excessive vasodilation.

Moderate Interactions (Monitor Closely)

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