isosorbide dinitrate: clinical use

Prescribing considerations

• Confirm the formulation because standard and prolonged-release tablets have different release characteristics.
• Assess risks from postural hypotension, labile circulation, hypothyroidism, hypothermia, malnutrition and severe renal or hepatic disease.
• Hospital solution may adsorb onto PVC or polyurethane tubing; use compatible administration equipment.
• Review sugar-containing tablet excipients where relevant.

Contraindications and cautions

• Hypersensitivity to isosorbide dinitrate or other nitrates
• Concurrent PDE-5 inhibitor or riociguat treatment
• Severe hypotension, hypovolaemia or acute circulatory failure
• Marked anaemia
• Acute myocardial infarction with low filling pressure
• Head trauma, cerebral haemorrhage or raised intracranial pressure
• Selected obstructive, valvular or restrictive cardiac conditions, as specified in the product SmPC

Monitoring

• Blood pressure, including postural symptoms, and heart rate
• Angina or heart-failure response and any paradoxical worsening of angina
• For infusion, continuous clinical assessment with pulse and blood-pressure monitoring
• Consider methaemoglobinaemia if cyanosis, tachypnoea or altered consciousness occurs, particularly after excessive exposure

Clinical pharmacology

An organic nitrate and nitric oxide donor that activates guanylyl cyclase and increases cyclic GMP. Predominant venodilation reduces preload; arterial dilation can reduce afterload. Active mononitrate metabolites contribute to its effects.

Formulation and product differences

• Standard tablets are licensed for angina prophylaxis and congestive cardiac failure.
• Prolonged-release tablets provide slower release and must be swallowed without chewing.
• Injection or infusion is restricted to monitored hospital use for selected acute cardiac indications and angioplasty-related coronary spasm.

Tablet

Route: Oral

Strengths: 10 mg, 20 mg

Injection

Route: Parenteral

Strengths: 1 mg/mL, 0.05% w/v, 0.1% w/v