Tricyclic Antidepressant (TCA) Pregnancy: Not recommended during pregnancy unless clearly necessary and only after careful risk/benefit consideration; neonatal withdrawal symptoms can occur with chronic use or use in the final weeks of pregnancy

Amitriptyline

Brand names: Tryptizol

Used in: Headache & Migraine

Amitriptyline is a tricyclic antidepressant used at low dose for neuropathic and chronic pain (and, at higher doses historically, for depression). It is sedating and usually taken at night.

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: Depression (elderly >65 years / cardiovascular disease): initially 10 mg–25 mg daily

Route: Oral

Frequency: Once daily initially; maintenance dose divided into two doses

Max: May be increased up to 100 mg–150 mg daily; doses above 100 mg should be used with caution

SPC elderly (>65 yr) / cardiovascular-disease dose. Major depressive disorder: initiate at a low level and increase gradually; daily dose may be increased up to 100 mg–150 mg divided into two doses depending on individual response and tolerability; doses above 100 mg with caution; maintenance is the lowest effective dose. Neuropathic pain / chronic tension-type headache prophylaxis / migraine prophylaxis (elderly >65 yr / CV disease): a starting dose of 10 mg–25 mg in the evening is recommended; doses above 75 mg should be used with caution; initiate in the lower dose range as for adults and increase per individual response/tolerability. Elderly patients are particularly susceptible to orthostatic hypotension.

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 Oral Dosage Dosage should be initiated at a low level and increased gradually, noting carefully the clinical response and any evidence of intolerance. Initial Dosage for Adults For outpatients, 75 mg of amitriptyline hydrochloride a day in divided doses is usually satisfactory. If necessary, this may be increased to a total of 150 mg per day. Increases are made preferably in the late afternoon and/or bedtime doses. A sedative effect may be apparent before the antidepressant effect is noted, but an adequate therapeutic effect may take as long as 30 days to develop. An alternate method of initiating therapy in outpatients is to begin with 50 to 100 mg amitriptyline …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-06-12. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Recent myocardial infarction
Any degree of heart block or disorders of cardiac rhythm and coronary artery insufficiency
Concomitant treatment with MAOIs (monoamine oxidase inhibitors)
Severe liver disease
Children under 6 years of age

Side effects

Orthostatic hypotension (very common)
Palpitations, tachycardia (very common)
Somnolence, tremor, dizziness, headache, drowsiness, dysarthria (very common)
Dry mouth, constipation, nausea (very common)
Delirium in elderly patients (rare)

Interactions

MAOIs — concomitant use contraindicated; may cause serotonin syndrome (14-day washout for irreversible non-selective MAOIs, 1 day for moclobemide)
Anaesthetics — may increase risk of arrhythmias and hypotension during tri/tetracyclic antidepressant therapy
QT-prolonging drugs — caution; cases of QT prolongation and arrhythmia reported

Clinical monograph

How it works

It inhibits reuptake of serotonin and noradrenaline and has antihistamine and anticholinergic actions.

Prescribing in practice

Anticholinergic effects (dry mouth, constipation, urinary retention, confusion) are a particular concern in older patients.
Use caution in cardiac disease and arrhythmia; it is dangerous in overdose.
Taper rather than stopping abruptly.

Monitoring

Review pain benefit, sedation and anticholinergic effects; consider cardiac risk at higher doses.

Counselling the patient

Take it at night, as it causes drowsiness.
Dry mouth and constipation are common.
Do not stop suddenly, and keep it away from children (dangerous in overdose).

Evidence & guidelines

A first-line option for neuropathic pain per NICE CG173.

Reference: NICE CG173 (Neuropathic Pain); AGS Beers Criteria 2023; STOPP/START v3; ACB scale; 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).

Curated clinical cross-links plus same-class fallbacks.

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