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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 Hydrochloride

Brand names: Elavil (discontinued UK), generic only

Amitriptyline hydrochloride is the salt form of the tricyclic antidepressant amitriptyline, used at lower doses for neuropathic pain and migraine prophylaxis and at higher doses for depression when alternatives are not suitable.

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: Major depressive disorder (adults): initially 25 mg twice daily (50 mg daily)
Route: Oral
Frequency: Twice daily
Max: Up to 150 mg daily divided into two doses
SPC main dose. Depression: initiate at a low level and increase gradually; if necessary increase by 25 mg every other day up to 150 mg daily divided into two doses; maintenance is the lowest effective dose; antidepressant effect usually sets in after 2–4 weeks; continue usually up to 6 months after recovery to prevent relapse. Elderly (>65 yr) / cardiovascular disease: initially 10 mg–25 mg daily, may increase up to 100 mg–150 mg in two divided doses; doses above 100 mg with caution. Neuropathic pain / chronic tension-type headache prophylaxis / migraine prophylaxis (adults): 25 mg–75 mg daily in the evening; initial dose 10 mg–25 mg in the evening, increased by 10 mg–25 mg every 3–7 days as tolerated, once daily or divided into two doses; a single dose above 75 mg is not recommended; doses above 100 mg with caution; analgesic effect normally seen after 2–4 weeks.

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.

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)
  • Hyperhidrosis (very common)

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 serotonin and noradrenaline reuptake and antagonises histaminergic, muscarinic and alpha-adrenergic receptors, accounting for its analgesic and antidepressant actions alongside its sedative and anticholinergic effects.

Prescribing in practice

  • It is toxic and potentially fatal in overdose through cardiac arrhythmia and seizures, so supply should be limited where there is a risk of self-harm.
  • Common anticholinergic effects include dry mouth, constipation, urinary retention and blurred vision, and caution is required in the elderly and in cardiovascular disease.
  • It is sedating, usually given at night, and titrated upwards slowly to improve tolerability.

Monitoring

Monitor mood and emergent suicidal thoughts early in treatment along with cardiovascular and anticholinergic tolerability.

Counselling the patient

  • When used for pain or migraine the dose is lower than for depression, and full benefit can take several weeks.
  • Expect possible drowsiness, dry mouth and constipation, particularly at the start.
  • Do not stop abruptly, and seek help urgently if mood deteriorates or self-harm thoughts arise.

Evidence & guidelines

Amitriptyline is recommended by NICE as a first-line treatment for neuropathic pain and is a long-established tricyclic antidepressant.

Reference: NICE NG193 (Neuropathic pain, 2020); NICE NG150 (Headaches: diagnosis and management, 2021); NICE NG222 (Depression in adults, 2022); 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).

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