Isoket Spray Zur Anwendung Bei Erwachsenen (Isosorbide Dinitrate)

Isosorbide Dinitrate is employed in the management of coronary artery disease, specifically for angina control.

• Angina pectoris: provides prophylaxis and rapid relief of chest pain by reducing myocardial oxygen demand.
• Chronic stable angina: improves exercise tolerance and decreases frequency of anginal episodes.
• Exercise‑induced angina: lessens attacks triggered by physical activity through sustained vasodilation.

• Isosorbide dinitrate is metabolized to release nitric oxide, which activates guanylate cyclase in vascular smooth‑muscle cells. The resulting increase in cyclic GMP leads to relaxation of arterial and venous smooth muscle, producing vasodilation, reduced preload and afterload, and consequently lower myocardial oxygen consumption. The effect is dose‑dependent and reversible, allowing titration to achieve desired anti‑anginal benefit while minimizing hemodynamic compromise.

Common and serious adverse reactions have been reported with isosorbide dinitrate use.

Common Side Effects

• Headache: throbbing pain often occurring shortly after administration.
• Flushing: warmth and redness of the face and neck.
• Dizziness or light‑headedness: related to blood pressure reduction.
• Hypotension: mild to moderate drop in blood pressure.
• Nausea: occasional gastrointestinal upset.
• Tachycardia: compensatory increase in heart rate.

Serious or Rare Side Effects

• Severe hypotension: marked blood pressure fall requiring medical attention.
• Syncope: fainting episodes due to cerebral hypoperfusion.
• Myocardial infarction: rare occurrence linked to abrupt nitrate withdrawal.
• Allergic reaction: rash, itching, or swelling of the face, lips, or tongue.
• Methemoglobinemia: rare discoloration of blood causing cyanosis.

When prescribing isosorbide dinitrate, several precautions should be observed to ensure safe use.

• Avoid concurrent use with phosphodiesterase‑5 inhibitors: may cause profound hypotension.
• Monitor blood pressure regularly: risk of symptomatic hypotension especially after first doses.
• Assess for tolerance development: efficacy may diminish with continuous use, requiring drug‑free intervals.
• Use with caution in patients with severe anemia or hemoglobinopathies: increased risk of methemoglobinemia.
• Educate patients on proper spray technique: administer to the oral mucosa, avoid swallowing immediately.
• Do not use in patients with known hypersensitivity to organic nitrates: risk of allergic reactions.
• Store at room temperature: keep in the original container, protect from moisture and light.

Isosorbide dinitrate can interact with several medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Sildenafil, tadalafil, vardenafil (PDE5 inhibitors): concurrent use can precipitate profound, potentially life‑threatening hypotension and should be avoided.
• Other nitrates (nitroglycerin, isosorbide mononitrate): combined therapy produces additive vasodilation, increasing risk of severe hypotension and syncope.
• Alcohol: ingestion may amplify the blood‑pressure‑lowering effect and cause dizziness.

Moderate Interactions (Monitor Closely)

• Antihypertensives (ACE inhibitors, beta‑blockers, calcium channel blockers): co‑administration may enhance overall blood pressure reduction, requiring closer monitoring.
• Diuretics: may predispose to orthostatic hypotension, especially during initial dosing.
• Antidepressants (SSRIs): can modestly influence nitrate metabolism, warranting observation for altered efficacy.