BMA Concise Guide to Medicine & Drugs

Amitriptyline

Brand names None

Used in the following combined preparations Triptafen, Triptafen-M

QUICK REFERENCE

Drug group Tricyclic antidepressant drug

Overdose danger rating High

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Amitriptyline belongs to the tricyclic group of antidepressant group of drugs. They are effective for long-term depression but are poorly tolerated and dangerous in overdose so they are second-line choices after SSRI antidepressants. The sedative effect of amitriptyline is useful when depression is accompanied by anxiety or insomnia. Taken at night, the drug encourages sleep and reduces the need for additional sleeping drugs. Amitriptyline is sometimes used to treat nocturnal enuresis (bedwetting) in children. It may also be used to treat neuropathic pain such as postherpetic neuralgia after shingles and to prevent migraine. In overdose, amitriptyline may cause abnormal heart rhythms, seizures, and coma.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, liquid.

Frequency and timing of doses 1–3 x daily, usually as a single dose at night.

Adult dosage range 10–200mg daily.

Onset of effect Sedation can appear within hours, although full antidepressant effect may not be felt for 2–4 weeks.

Duration of action Antidepressant effect may last for 6 weeks; common adverse effects gone within 1 week.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children. Protect from light.

Missed dose Take as soon as you remember. If your next dose is due within 3 hours, take a single dose now and skip the next.

Stopping the drug An abrupt stop can cause withdrawal symptoms and recurrence of the original trouble. Consult your doctor, who may supervise a gradual reduction in dosage over at least 4 weeks.

OVERDOSE ACTION

Seek immediate medical advice in all cases. Take emergency action if palpitations are noted or consciousness is lost.

POSSIBLE ADVERSE EFFECTS

The possible adverse effects of this drug are mainly the result of its anticholinergic action and its blocking action on the transmission of signals through the heart. Common adverse effects include drowsiness, sweating, dry mouth, constipation, and blurred vision. Discuss with your doctor if any of these are severe or if you have difficulty in passing urine. If you experience dizziness, fainting, or confusion, stop taking the drug and consult your doctor. If you have palpitations, you should also stop taking the drug and should consult your doctor immediately.

INTERACTIONS

Monoamine oxidase inhibitors (MAOIs) In the rare cases where these drugs are given with amitriptyline, there is a possibility of serious interactions.

Anti-epileptics The effects of these drugs are reduced by amitriptyline as it lowers the threshold for seizures.

Sedatives All drugs that have sedative effects intensify those of amitriptyline.

Anti-arrhythmic drugs There is an increased risk of abnormal heart rhythms when these drugs are taken with amitriptyline.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have heart problems.

· You have had epileptic seizures.

· You have long-term liver or kidney problems.

· You have glaucoma.

· You have prostate trouble.

· You have thyroid disease.

· You have had mania or a psychotic illness.

· You are taking other medicines.

Pregnancy Avoid if possible. Discuss with your doctor.

Breast-feeding The drug passes into the breast milk, but at normal doses adverse effects are unlikely. Discuss with your doctor.

Infants and children Not recommended under 16 years for depression, or under 6 years for enuresis.

Over 60 Reduced dose may be necessary because elderly patients are more sensitive to adverse reactions.

Driving and hazardous work Avoid such activities until you have learned how amitriptyline affects you because the drug may cause blurred vision and reduced alertness.

Alcohol Avoid. Alcohol may increase the sedative effects of this drug.

Surgery and general anaesthetics Amitriptyline treatment may need to be stopped before you have a general anaesthetic. Discuss this with your doctor or dentist before any operation.

PROLONGED USE

No problems expected.