Isosorbide Mononitrate Vitabalans (Isosorbide Mononitrate)

Isosorbide Mononitrate is used within the anti‑anginal drug class to manage coronary artery disease and related chest pain.

• Angina pectoris (stable): reduces the frequency and severity of chest pain episodes.
• Chronic stable coronary artery disease: improves exercise tolerance and delays symptom onset.
• Prevention of angina attacks: maintains symptom control during daily activities.

• Isosorbide Mononitrate is metabolized to release nitric oxide, which activates guanylate cyclase in vascular smooth muscle. The resulting increase in cyclic GMP leads to relaxation of both venous and arterial vessels, decreasing preload and afterload. This vasodilation lowers myocardial oxygen consumption, thereby alleviating ischemic chest pain in patients with stable angina.

Isosorbide Mononitrate may cause a range of adverse reactions, most of which are dose‑related and reversible.

Common Side Effects

• Headache: throbbing pain often occurring shortly after dosing.
• Dizziness or light‑headedness: related to blood pressure reduction.
• Flushing: warm sensation and reddening of the skin.
• Nausea: mild gastrointestinal upset.
• Palpitations: awareness of heartbeat acceleration.
• Hypotension: mild drop in blood pressure, especially when standing.

Serious or Rare Side Effects

• Severe hypotension: marked blood pressure fall requiring medical attention.
• Syncope: sudden loss of consciousness.
• Myocardial infarction (rare): chest pain not relieved by medication.
• Allergic reactions: rash, itching, or swelling.
• Stevens‑Johnson syndrome (very rare): severe skin and mucous membrane involvement.

Before initiating therapy, clinicians should evaluate cardiovascular status and consider patient‑specific factors.

• Assess blood pressure: ensure baseline values are adequate to tolerate vasodilation.
• Review cardiac history: avoid in patients with recent myocardial infarction or unstable angina.
• Monitor for drug tolerance: dose‑related headaches may require adjustment.
• Caution in elderly: increased sensitivity to hypotensive effects.
• Avoid abrupt discontinuation: may precipitate rebound angina.
• Store at ambient temperature below 25°C: keep in the original container, protect from moisture and direct sunlight.

Isosorbide Mononitrate can interact with several drug classes, influencing blood pressure and nitrate metabolism.

Major Interactions (Avoid)

• Other nitrates (e.g., nitroglycerin): additive vasodilation leading to severe hypotension.
• Phosphodiesterase‑5 inhibitors (e.g., sildenafil): risk of profound blood pressure drop.
• Antihypertensive agents (e.g., ACE inhibitors, beta‑blockers): may cause excessive blood pressure reduction.

Moderate Interactions (Monitor Closely)

• Diuretics: can enhance hypotensive response.
• Alcohol: may increase dizziness and vasodilatory effects.
• Azole antifungals (e.g., ketoconazole): may raise plasma levels of isosorbide mononitrate.
• Calcium channel blockers: potential additive effect on blood pressure.
• Certain antiretrovirals: may alter nitrate metabolism.