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Organic nitrate Pregnancy: Safety in human pregnancy has not been established, although no data have been reported suggesting adverse effects. Should only be used during pregnancy and lactation if the benefits of treatment outweigh the possible hazards.

Isosorbide dinitrate

Brand names: Isoket, Cedocard

Isosorbide dinitrate is a nitrate used for the prophylaxis and treatment of angina and as an adjunct in heart failure.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Intravenous infusion: typically 2 mg to 12 mg per hour, adjusted according to patient response
Route: Intravenous infusion - may be administered undiluted by slow intravenous infusion using a syringe pump. Avoid administration through PVC or PU tubing and giving sets because of adsorption of isosorbide dinitrate onto plastic. Also licensed for intracoronary injection
Frequency: Continuous infusion, titrated to response (blood pressure and pulse rate should always be monitored and the dose adjusted according to the patient's response)
Max: The SPC states doses of up to 20 mg per hour may be necessary (no absolute maximum is stated). Intracoronary: additional doses may be given, not exceeding 5 mg over 30 minutes
SOURCE SCOPE: the SPC fetched is 'Isosorbide Dinitrate 0.05% w/v Solution for Injection or Infusion' - it covers the intravenous and intracoronary routes only. Oral, sublingual and transdermal/spray isosorbide dinitrate regimens are NOT covered by this source and must be sourced separately before being shown on this page. Intracoronary administration: the usual dose is 1 mg given as a bolus injection prior to balloon inflation; additional doses may be given, not exceeding 5 mg over 30 minutes. Elderly: no modification to the dosage is necessary. Paediatric: safety and efficacy have not been established in children. Presented in 50 mL vials intended for single use only. Tolerance and cross-tolerance to other nitrates have been described - to prevent decrease in or loss of effect, continuously high dosages must be avoided. Cross-check only (openFDA, US labelling for the ORAL immediate-release tablets, not the UK injection SPC): usual starting dose 5 mg to 20 mg two or three times daily, maintenance 10 mg to 40 mg two or three times daily, with a daily dose-free interval of at least 14 hours to minimise tolerance - this US oral figure has NOT been used for the dose field and needs clinician confirmation against a UK oral product SPC.

Dose adjustments

Renal

No numeric dose adjustment is stated. Use with caution and under medical supervision in patients with severe liver or renal disease (SPC section 4.4).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION As noted under " CLINICAL PHARMACOLOGY ," multiple-dose studies with isosorbide dinitrate and other nitrates have shown that maintenance of continuous 24-hour plasma levels results in refractory tolerance. Every dosing regimen for isosorbide dinitrate tablets must provide a daily dose-free interval to minimize the development of this tolerance. With immediate-release isosorbide dinitrate, it appears that one daily dose-free interval must be at least 14 hours long. As also noted under " CLINICAL PHARMACOLOGY ," the effects of the second and later doses have been smaller and shorter-lasting than the effects of the first. Large controlled studies with other nitrates …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2026-02-10. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

  • Known hypersensitivity to nitrates, or to the active substance or any of the excipients
  • Marked anaemia
  • Cerebral haemorrhage, head trauma, diseases associated with increased intracranial pressure
  • Hypovolaemia and severe hypotension (systolic blood pressure less than 90 mmHg); circulatory collapse or low filling pressure
  • Aortic and/or mitral valve stenosis; closed angle glaucoma
  • Hypertrophic obstructive cardiomyopathy, constrictive pericarditis or cardiac tamponade
  • Co-administration with phosphodiesterase type-5 inhibitors (e.g. sildenafil, tadalafil, vardenafil), which potentiate the hypotensive effects of nitrates
  • Cardiogenic shock - treatment should only be undertaken if means of maintaining an adequate diastolic pressure is available

Side effects

  • Headache, dizziness, somnolence
  • Orthostatic hypotension, collapse (sometimes with bradyarrhythmia and syncope)
  • Tachycardia, aggravated angina pectoris
  • Nausea, vomiting, heartburn
  • Allergic skin reactions (e.g. rash), flush, angioedema, Stevens-Johnson syndrome; in single cases exfoliative dermatitis
  • Temporary hypoxaemia due to relative redistribution of blood flow in hypoventilated alveolar areas, which in coronary artery disease may lead to myocardial hypoxia

Interactions

  • Drugs with blood pressure lowering properties (beta-blockers, calcium antagonists, vasodilators) and/or alcohol - may potentiate the hypotensive effect
  • Neuroleptics and tricyclic antidepressants - may potentiate the hypotensive effect
  • Phosphodiesterase-5 inhibitors (e.g. sildenafil) - potentiate the hypotensive effect and may lead to life-threatening cardiovascular complications; co-administration is contraindicated
  • Dihydroergotamine - isosorbide dinitrate may increase its blood level and hypertensive effect

Clinical monograph

How it works

It is converted to nitric oxide, which relaxes vascular smooth muscle, causing venous and arterial dilatation that reduces cardiac preload, afterload and myocardial oxygen demand.

Prescribing in practice

  • It is contraindicated with phosphodiesterase type-5 inhibitors such as sildenafil because of the risk of severe hypotension.
  • Nitrate tolerance develops with continuous exposure, so dosing should allow a daily nitrate-free interval.
  • Headache and hypotension are common, particularly at the start of treatment.

Monitoring

Monitor blood pressure and angina control, and review for tolerance with regular dosing.

Counselling the patient

  • Do not take medicines for erectile dysfunction such as sildenafil with this medicine.
  • Headache is common early on and usually settles; report fainting or severe dizziness.

Evidence & guidelines

An established nitrate for angina prophylaxis and a recognised adjunct in heart failure in UK practice.

Reference: ESC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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