Nitroglycerin

NTG Full Form in English, letter by letter

NTG is the short form of nitroglycerin, also called glyceryl trinitrate (GTN), a medicine that relieves angina chest pain.

NTG Full Form in Indian Languages

NTG is the abbreviation doctors and nurses write for Nitroglycerin, the tablet kept under the tongue for chest pain. Its name appears below in six Indian languages.

Nitroglycerin as a heart medicine

Nitroglycerin, also called glyceryl trinitrate or GTN, is a nitrate medicine. For an angina attack it is taken as a sublingual tablet or a spray, which means it is placed under the tongue and not swallowed. The thin lining there absorbs the drug straight into the blood, and relief usually starts within a few minutes.

It works by relaxing the walls of blood vessels. The veins widen, so less blood returns to the heart, and the heart has less work to do and needs less oxygen. That is why patients are told to sit down before taking a dose: the same widening can make blood pressure fall and cause dizziness.

Forms, brands and other uses

In India, sublingual GTN tablets are sold under brands such as Angised. Be careful with look-alike names: sustained-release products such as Nitrocontin are taken regularly for prevention and are not meant to be used as an emergency tablet under the tongue.

Hospitals use intravenous GTN in acute heart failure, in a heart attack with high blood pressure and during some surgeries. A low-strength ointment is prescribed for anal fissure, and skin patches exist for prevention. Doctors usually ask angina patients to keep a supply at home, at work and in the bag they carry, because attacks often begin away from a hospital.

From explosive oil to bedside drug

Italian chemist Ascanio Sobrero first made nitroglycerin in 1847 and quickly saw that it was dangerously unstable. Alfred Nobel found a safer way to handle it in 1867 by absorbing it into a porous earth, which gave him dynamite and the fortune that later funded the Nobel Prizes.

In the nineteenth century, doctors found that tiny doses relieved chest pain. The link is nitric oxide, which the molecule releases in the body and which relaxes smooth muscle in blood vessels. Nobel himself was later advised to take nitroglycerin for his own heart condition.

Storing and taking GTN tablets safely

Keep tablets in the original glass bottle with the cap shut, away from heat, light and damp. A bathroom shelf is a poor place. Moving them to a pill box can weaken them, and an old tablet may still cause a headache while relieving little pain. Check the expiry date and the bottle's opening date when you buy.

Sit down, place one tablet under the tongue and let it dissolve. If the pain is not relieved five minutes after the first dose, standard advice is to call for emergency help, because the cause may be a heart attack. Do not drive yourself. A cardiologist may give a precise plan for your case, and you should follow that plan over general advice.

If you are travelling, carry the bottle in a pocket and not in checked luggage, and tell a companion where it is. Spray forms are an alternative for people who find it hard to place a tablet under the tongue, and they have their own storage rules.

Side effects, tolerance and daily nitrates

Headache, flushing, dizziness and light-headedness on standing are the usual effects. They tend to fade with use. A faint, a very fast heartbeat or a headache that will not settle should be reported to a doctor.

Regular nitrate use can lead to tolerance, which is why doctors plan a nitrate-free gap, often overnight. Long-acting nitrates such as isosorbide mononitrate are taken every day for prevention. They do not replace the rescue tablet. An ECG and other tests help the doctor decide which combination of drugs suits a patient.

What to tell your doctor before using it

Doctors ask about blood pressure, recent use of sildenafil or tadalafil, glaucoma, anaemia and migraine before prescribing GTN. The drug interacts with erectile dysfunction pills, and the combination can cause a dangerous drop in blood pressure. The usual gap is at least 24 hours after sildenafil and 48 hours after tadalafil.

Carry the exact brand and strength rather than saying 'the heart tablet'. A pharmacist should not swap one nitrate for another without checking with the prescriber.

Also tell the doctor if you have ever felt faint after a nitrate, since low blood pressure is the main risk. People with very low blood pressure or severe narrowing of the aortic valve usually need supervision before using the drug.

On a prescription or a hospital chart, NTG almost always means Nitroglycerin. It is a small tablet that does a large job, and it is worth knowing how to store it and when not to rely on it.

NTG Full Form: Common Questions