Glyceryl Trinitrate (GTN / Nitroglycerin)

Glyceryl Trinitrate (GTN / Nitroglycerin) is a nitrate vasodilator (anti-anginal) medicine available in Bangladesh under many brand names. Below are its uses, side effects and precautions — and every brand with its current price.

• Acute angina attack — rapid relief of chest pain (sublingual tablet or spray)
• Prevention before exertion — taken minutes before activity known to trigger chest pain, such as climbing stairs
• Angina prophylaxis — longer-acting tablets or patches to reduce attack frequency
• Hospital uses — heart attack, acute heart failure and blood pressure control during surgery (infusion form)
• Anal fissure — special ointment form, as prescribed

Most side effects come from blood vessels widening and are strongest in the first doses:

• Throbbing headache — very common; usually eases with continued use and responds to paracetamol
• Flushing, warmth of the face and neck
• Dizziness, light-headedness or faintness, especially on standing
• Fast heartbeat (palpitations)
• Low blood pressure; nausea
• Burning or tingling under the tongue (sublingual forms) — a sign the tablet is active
• Seek help if: fainting, severe persistent dizziness, blurred vision, or chest pain that does not settle

• Always sit down before taking a sublingual dose — the sudden pressure drop can cause fainting if you are standing.
• Carry Glyceryl Trinitrate (GTN / Nitroglycerin) with you at all times; an angina attack cannot be scheduled.
• Do not drink alcohol around dosing — it multiplies the pressure drop.
• Rise slowly afterwards; avoid driving until dizziness passes.
• Tell your doctor if attacks become more frequent, occur at rest or wake you at night — this is unstable angina and needs urgent review.
• With regular long-acting nitrates, the body develops tolerance — your doctor will plan a daily nitrate-free interval; do not add extra doses yourself.
• Check the expiry and replace sublingual tablets as advised once the bottle is opened — old tablets lose potency.

• Erectile dysfunction medicines (sildenafil, tadalafil, vardenafil): absolutely must not be combined — together they can cause a catastrophic, life-threatening fall in blood pressure. A gap of at least 24 hours (sildenafil) or 48 hours (tadalafil) is required, decided by a doctor
• Riociguat: similarly contraindicated
• Other blood pressure medicines, beta-blockers, calcium channel blockers, diuretics: additive pressure drop
• Alcohol: increases dizziness and hypotension
• Ergotamine (migraine): nitrates can oppose it and ergotamine can worsen angina
• Heparin (infusion setting): effect may be reduced

Tell your doctor about all medicines you use — especially any medicine for erection problems.

• Allergy to glyceryl trinitrate or other nitrates
• Use of sildenafil, tadalafil, vardenafil or riociguat within the prohibited interval
• Severe low blood pressure or shock; severe anaemia
• Raised pressure inside the skull (head injury, brain haemorrhage)
• Hypertrophic obstructive cardiomyopathy, severe aortic stenosis, constrictive pericarditis (specialist assessment needed)
• Closed-angle glaucoma

Pregnancy: Glyceryl trinitrate is used in pregnancy only if the doctor judges the benefit outweighs the risk — human data are limited. It is sometimes used in hospital obstetric settings under specialist supervision. Tell your doctor if you are or may be pregnant before using it regularly.

Lactation: It is not known how much passes into breast milk. Occasional sublingual use is unlikely to be a problem, but discuss regular use with your doctor, who will weigh the options and monitor the baby if needed.

Storage is critical for this medicine: glyceryl trinitrate evaporates and loses potency easily. Keep sublingual tablets in the original glass container, tightly closed, without cotton wool or other tablets inside, away from heat, light and moisture — not in a car or pocket close to the body for long periods. Store below 25–30°C, replace opened sublingual tablets as advised (often every 8 weeks to 6 months per manufacturer), and keep out of the reach of children. Spray forms last longer — check the label and expiry date.