Amitriptyline
An old antidepressant reborn as a low-dose night-time tablet for nerve pain, migraine prevention and IBS. Helpful for many, sedating for most, dangerous in overdose.
At a glance
- For
- Nerve pain, migraine and tension headache prevention, IBS (mostly off-label, low dose); depression (rarely now)
- Works
- Helps some people: for nerve pain, about 1 extra person in 5 gets real relief compared with a dummy treatment (evidence modest). Low doses clearly helped IBS in a large UK trial
- Cost
- Under the $25 PBS co-payment, about $22 for 50 tablets; $7.70 concession
- Kicks in
- Sleepiness from the first night; pain benefit in 2–6 weeks
- Taken for
- Months, then reviewed (often at 6–12 months)
- Watch for
- Drowsiness, dry mouth, constipation, weight gain, dizziness on standing
Take it 1–2 hours before bed, not at midnight, unless you enjoy mornings that feel like wading through custard.
Brand names
- Endep, plus generic brands sold as amitriptyline
How it works
It raises serotonin and noradrenaline in the brain and spinal cord, turning down pain signals. Pain doses (often 5 to 50 mg at night) are much lower than depression doses.
Used for
- Depression (TGA-approved, but now rarely used for this because of side effects and overdose risk)
- Bed-wetting in children, after other causes are excluded (TGA-approved)
- Nerve pain, e.g. shingles pain or diabetic nerve pain (off-label)
- Migraine and tension headache prevention (off-label)
- IBS: low doses improved symptoms in the 2023 ATLANTIS trial in UK general practice (off-label)
Side effects
Full side-effect list (from the product information)
How often, from the official product information. Bold = serious.
Very common more than 1 in 10
- Drowsiness, dizziness, headache, tremor
- Dry mouth, constipation, nausea
- Blurred near vision, blocked nose
- Fast heartbeat, dizzy on standing
- Sweating, weight gain
- Slurred speech, aggression
Common 1 in 10 to 1 in 100
- Confusion, agitation, low sodium
- Poor focus, odd taste, pins and needles
- Unsteadiness, large pupils
- Heart block, long QT on ECG
- Trouble passing urine
- Low sex drive, erection problems
- Tiredness, thirst
Uncommon 1 in 100 to 1 in 1,000
- Anxiety, poor sleep, nightmares, mania
- Seizures, collapse, worse heart failure
- High blood pressure, ringing ears
- Diarrhoea, vomiting, liver problems
- Rash, hives, flushing, face swelling
- Unable to pass urine, raised eye pressure
Rare 1 in 1,000 to 1 in 10,000
- Low white cells or platelets
- Delirium (older people), hallucinations
- Suicidal thoughts, irregular heart rhythm
- Bowel paralysis, jaundice
- Hair loss, sun sensitivity, fever
- Breast swelling in men
Very rare fewer than 1 in 10,000
- Restlessness (akathisia), nerve damage
- Acute glaucoma (painful red eye)
- Heart muscle disease, torsades
- Lung inflammation
Frequency not known reported, rate unclear
- Anaphylaxis or angioedema
- Severe skin reaction (DRESS)
- Paranoia, movement problems, dry eyes
- Hepatitis, overheating
Get help urgently if
- Overdose is life-threatening, even a few days’ supply. Call 000, or Poisons Information 13 11 26
- Fainting, chest pain or a racing, irregular heartbeat
- A painful red eye with blurred vision
- Unable to pass urine, or severe constipation with tummy swelling
- Thoughts of self-harm: Lifeline 13 11 14
Good to know
- Older people: drowsiness, dizziness on standing and confusion raise the risk of falls. Low doses are used.
- Avoid alcohol and other sedating medicines. Don’t drive until you know how it affects you.
- Many medicines interact, incl. other antidepressants and tramadol. Check with your pharmacist.
- Don’t stop suddenly after long use. Pregnancy or breastfeeding: talk to your doctor. Store out of reach of children.
Support lines
If you or someone else is in danger right now, call your emergency number. To talk to someone, any time:
- Australia: Lifeline 13 11 14 (24/7, or text 0477 13 11 14), Suicide Call Back Service 1300 659 467, Beyond Blue 1300 22 4636, 13YARN 13 92 76 for Aboriginal and Torres Strait Islander people. Emergency: 000.
- Young people in Australia: Kids Helpline 1800 55 1800 (24/7, ages 5 to 25) or headspace (ages 12 to 25).
- New Zealand: call or text 1737. Emergency: 111.
- UK and Ireland: Samaritans 116 123. Emergency: 999 (or 112).
- US and Canada: call or text 988. Emergency: 911.
- Anywhere else: findahelpline.com lists free helplines in more than 100 countries.
Common questions
Why is amitriptyline used for pain?
In low doses it turns down pain signals in the brain and spinal cord. Pain doses (often 5 to 50 mg at night) are much lower than depression doses. It helps some people, not everyone.
How long does amitriptyline take to work for pain?
The pain benefit can take 2 to 6 weeks. It is taken 1 to 2 hours before bed, as drowsiness is common.
Is amitriptyline dangerous in overdose?
Yes. An overdose, even of a few days’ supply, is life-threatening. Store it out of reach of children, and call 000 or Poisons Information on 13 11 26 if too much is taken.
What is amitriptyline used for?
In Australia it’s mostly used in low doses for nerve pain, preventing migraine and tension headaches, and for IBS. It was first an antidepressant, but higher depression doses are rarely used now because of side effects.
What are the side effects of amitriptyline?
Drowsiness, dry mouth, constipation, weight gain and dizziness when standing up are common, especially early on. Older people are more prone to confusion and falls. Many side effects ease after a few weeks.
Does amitriptyline help you sleep?
It often makes people drowsy, but it isn’t recommended just for insomnia, as the evidence is weak and side effects add up. CBT for insomnia works better and lasts longer.
Can I drink alcohol on amitriptyline?
It’s best to avoid alcohol or keep it to a minimum. Together they increase drowsiness and dizziness, which raises the risk of falls and accidents.
Information only. Not a recommendation or endorsement of any product. Whether a medicine suits you depends on your health and other medicines, so talk to your doctor or pharmacist. In an emergency, call 000 (Australia) or your local emergency number. From a mobile, 112 works in most countries.
More information
- Amitriptyline 10 mg SmPC (UK, Brown & Burk)
- NIHR: Low-dose amitriptyline for IBS (ATLANTIS)
- Healthdirect: Medicines information
- Cochrane: Amitriptyline for neuropathic pain in adults
- PBS: Amitriptyline 10 mg
maladywise.com/medicines/amitriptyline/