This site is intended for UK healthcare professionals
Medscape UK Univadis Logo
Medscape UK Univadis Logo

Glyceryl trinitrate oral

Updated 2 Feb 2023 | Short acting nitrates


Tablet formulations of sublingual glyceryl trinitrate.

Drugs List

  • glyceryl trinitrate 500microgram tablets
  • glyceryl trinitrate 600microgram tablets
  • Therapeutic Indications


    Prinzmetal angina
    Prophylaxis of angina pectoris
    Treatment of angina pectoris



    Treatment of acute attacks of angina pectoris
    When angina starts, 300 micrograms to 1 mg of glyceryl trinitrate should be taken. If symptoms do not resolve, glyceryl trinitrate may be repeated at 5 minute intervals for a total of three doses.

    If symptoms have not resolved after a total of three doses, the patient should seek prompt medial attention.

    Prophylaxis of angina pectoris
    The recommended dose is 300 micrograms to 1 mg. May be used prior to activity which is likely to precipitate angina pectoris.


    (See Dosage - Adults).


    Children under 18 years
    Aortic stenosis
    Cardiac tamponade
    Cardiogenic shock
    Cerebrovascular haemorrhage
    Circulatory failure
    Constrictive pericarditis
    Head trauma
    Hypertrophic obstructive cardiomyopathy
    Mitral stenosis
    Narrow angle glaucoma
    Raised intracranial pressure
    Severe anaemia
    Severe bradycardia
    Toxic pulmonary oedema

    Precautions and Warnings

    Low cardiac filling pressures
    Predisposition to narrow angle glaucoma
    Systolic blood pressure < 90mmHg
    Cerebrovascular disorder
    Glucose-galactose malabsorption syndrome
    Lactose intolerance
    Postural hypotension
    Severe hepatic impairment
    Severe renal impairment

    Lack of effect may indicate early myocardial infarction
    Advise ability to drive/operate machinery may be affected by side effects
    Contains lactose
    Advise patient to seek medical help if symptoms unresolved after 3 doses
    Moisten buccal mucosa in dry mouth
    Monitor patients at risk of glaucoma for increases in intraocular pressure
    Cross tolerance to other nitrates may develop
    Hypotensive effects may be potentiated by alcohol

    Certain conditions or medications (with anticholinergic effects) may precipitate a dry mouth which can reduce the effectiveness of sublingual nitrates. If patient has dry mouth, prior to tablet insertion they should moisten buccal mucosa.

    Patients particularly the elderly should be advised to sit down whenever possible when taking sublingual glyceryl trinitrate.

    Pregnancy and Lactation


    Use in pregnancy is not recommended unless considered essential by a physician.

    Glyceryl trinitrate is primarily used for treatment and prevention of angina and therefore experience of use in pregnancy is limited. Glyceryl trinitrate should not be used during pregnancy particularly during the first trimester unless the potential benefits outweigh the unknown risks to the foetus (Briggs, 2011). Schaefer (2007) comments that nitrates may be used in pregnancy for appropriate indications and toxic affects on the foetus have not been reported. Briggs (2011) adds that with smaller doses of nitrates a transient decrease in the mother's blood pressure may occur but does not seem to be sufficient to affect placental perfusion.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Use with caution during breastfeeding. Sublingual glyceryl trinitrate has not been studied during breastfeeding.

    Studies with other topical preparations (ointment) have been used to treat anal fissures on nursing mothers and there were no reported effects in the breastfed infant whilst a number of the known side effects (headache, dizziness, lightheaded) where reported in the mothers.

    It is recommended that infants be observed for flushing and discomfort following breastfeeding, since it is not known if glyceryl trinitrate is secreted in the breast milk. Hale (2010) recommends monitoring for methemoglobinemia and breastfeeding with caution at increased dosages with prolonged exposure, particularly in infants younger than 6 months.

    Toxic effects on the infant have not been reported; Schaefer (2007) states that data would argue against a toxic risk for the breastfed infant due to the short half-life of the drug and its usually brief use.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at


    Tablet(s) should be placed under the tongue and allowed to dissolve slowly. A fresh tablet should produce a slight burning sensation when placed under tongue; if not obtain fresh supply.

    If patient has dry mouth, prior to tablet insertion they should moisten buccal mucosa.

    Side Effects

    Allergic skin reactions
    Burning sensation (local)
    Cerebral ischaemia
    Circulatory collapse
    Decrease in blood pressure
    Exfoliative dermatitis
    Facial flushing
    Glaucoma (closed angle)
    Increased intra-ocular pressure
    Postural hypotension
    Respiration worsening
    Throbbing headache
    Tolerance to this drug and cross tolerance to other nitrates
    Transient hypoxaemia
    Worsening of angina


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: May 2013

    Reference Sources

    British National Formulary, 65th Edition (March - September 2013) Pharmaceutical Press, London.

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

    Martindale: The Complete Drug Reference, 37th edition (2011) ed. Sweetman, S. Pharmaceutical Press, London.

    Medications and Mothers' Milk, 14th Edition (2010) Hale, T. Hale Publishing, Amarillo, Texas.

    Summary of Product Characteristics: Glyceryl trinitrate tablets BP 500 micrograms. Actavis UK Ltd. Revised December 2012.

    Summary of Product Characteristics: Glyceryl trinitrate tablets BP 600 micrograms. Actavis UK Ltd. Revised December 2012.

    Access the full UK drug database with a FREE Medscape UK Account
    It takes just a few minutes, and you’ll get unlimited access to information on over 11,000 UK drugs.
    Register for Free

    Already a member? Log in

    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

    FDB Logo

    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.