Tricyclic Antidepressant (TCA)
Amitriptyline Hydrochloride
Brand names: Elavil (discontinued UK), generic only
Adult dose
Dose: Depression: 75 mg/day in divided doses or as single night dose; range 75–150 mg/day (hospital: up to 300 mg/day). Neuropathic pain/prophylaxis: 10–75 mg at night
Route: Oral
Frequency: Once at night (preferred) or in divided doses
Clinical pearls
- Most prescribed as low-dose for neuropathic pain, migraine prophylaxis, insomnia, or IBS (not as antidepressant in these indications)
- NICE NG193 (Neuropathic pain): amitriptyline 10–75 mg at night is a first-line option (with duloxetine, gabapentin, pregabalin)
- NICE NG150 (Headaches): amitriptyline is first-line for migraine prophylaxis
- For depression: SSRIs preferred (amitriptyline has unfavourable side effect profile)
- Dangerous in overdose — QRS widening and arrhythmias; avoid prescribing large quantities in suicide risk
- Low-dose (10–25 mg nocte) rarely causes significant cardiovascular effects
- Anti-muscarinic side effects lessen with time in most patients
Contraindications
- Recent myocardial infarction
- Arrhythmias (especially heart block)
- Mania
- Severe hepatic impairment
- Concurrent use with MAOIs (or within 14 days)
Side effects
- Antimuscarinic effects: dry mouth, constipation, urinary retention, blurred vision, confusion
- Sedation (very common)
- Postural hypotension
- Weight gain
- QTc prolongation (cardiotoxic in overdose)
- Lowered seizure threshold
- Sexual dysfunction
Interactions
- MAOIs — potentially fatal serotonin syndrome; contraindicated
- SSRIs/SNRIs — additive serotonergic effects
- CNS depressants — additive sedation
- Antiarrhythmics — additive QT prolongation
- Adrenaline/noradrenaline — potentiation of pressor effects (caution with dental anaesthetics)
- Cimetidine — increases TCA levels
Monitoring
- ECG before starting if cardiac risk (QTc baseline)
- Blood pressure (postural)
- Mood, suicidality (especially in early treatment of depression)
- Weight
Reference: BNF; NICE NG193 (Neuropathic pain, 2020); NICE NG150 (Headaches: diagnosis and management, 2021); NICE NG222 (Depression in adults, 2022); https://bnf.nice.org.uk/drugs/amitriptyline-hydrochloride/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Drugs
Same class
Pathways
Same specialty