Amitriptyline is a tricyclic antidepressant used at low amounts for nerve pain, migraine prevention and sleep, and at higher amounts for depression. Most people prescribed it are taking it for pain, not depression. It causes drowsiness, so it is usually taken at night.
What is Amitriptyline?
Amitriptyline is a tricyclic antidepressant (TCA), dispensed as 10 mg, 25 mg and higher-strength tablets. In South Africa it is sold under its own name and as Trepiline and Tryptanol. It is a Schedule 5 medicine.
It increases the amount of serotonin and noradrenaline available in the nervous system by blocking their reuptake. It also blocks histamine, acetylcholine and alpha-adrenergic receptors — which is where most of its side effects come from, and why it causes such marked drowsiness.
The most useful thing to understand about amitriptyline is that the amount changes what it is for.
| Amount | Typical purpose |
|---|---|
| 10–25 mg at night | Nerve pain, migraine prevention, sleep, fibromyalgia |
| 25–75 mg | Nerve pain at higher requirement; some anxiety |
| 75–150 mg+ | Depression |
Serotonin and noradrenaline are not only mood chemicals — they also carry the body’s own pain-damping signals down the spinal cord. Strengthening those pathways reduces pain perception, and this works at amounts far below those needed for depression, and regardless of whether the person is depressed.
So being prescribed an antidepressant for pain is not a suggestion that the pain is imaginary. It is a well-established use of the medicine, and at 10 or 25 mg it is not being used as an antidepressant at all.
What is Amitriptyline commonly used for?
At low amounts:
- Neuropathic (nerve) pain — diabetic neuropathy, post-shingles pain, sciatica, nerve injury. This is its commonest use.
- Migraine prevention, reducing how often attacks occur.
- Chronic tension headache.
- Fibromyalgia, for pain and sleep.
- Insomnia, particularly with chronic pain.
- Irritable bowel syndrome, where gut pain sensitivity is prominent.
- Bladder pain syndrome.
At higher amounts:
- Depression, though SSRIs are generally first-line now because they are better tolerated.
- Anxiety, in some cases.
Bedwetting in children, under specialist supervision.
Two practical points.
It takes time. For nerve pain, expect two to six weeks at a steady amount before judging it. People frequently stop after a week concluding it does not work.
It is usually started very low and increased slowly. Starting at 10 mg and building up allows the drowsiness and dry mouth to settle as you go. Beginning at a higher amount is generally intolerable.
For nerve pain specifically, ordinary painkillers work poorly — paracetamol and anti-inflammatories do relatively little for it, which is why a medicine like amitriptyline or pregabalin is used instead.
How Amitriptyline fits into this medicine category
| Group | Examples | Role |
|---|---|---|
| Tricyclic antidepressants | Amitriptyline (Trepiline), nortriptyline | Nerve pain, migraine prevention, sleep; depression at higher amounts |
| SSRIs / SNRIs | Escitalopram, sertraline, duloxetine | First-line depression and anxiety; duloxetine also for nerve pain |
| Anticonvulsants | Pregabalin (Nurika), gabapentin | Nerve pain, epilepsy |
| Benzodiazepines | Clobazam (Urbanol), clonazepam (Rivotril) | Short-term anxiety; seizures |
| Simple analgesics and NSAIDs | Paracetamol, ibuprofen | Ordinary pain; poor for nerve pain |
See the mental health and neurology medicines hub.
What to check before using Amitriptyline
Take it in the evening, two to three hours before bed rather than at bedtime — this reduces the morning grogginess people often complain of.
Do not drive until you know how it affects you. Drowsiness commonly persists into the morning, especially early on.
Avoid alcohol, which adds to the sedation.
Tell your prescriber or pharmacist if:
- You have a heart condition, particularly a rhythm problem, a long QT interval, or a recent heart attack. TCAs affect heart conduction, and this is the most important cardiac caution.
- You have glaucoma, particularly narrow-angle.
- You have an enlarged prostate or difficulty passing urine.
- You have epilepsy — amitriptyline lowers the seizure threshold.
- You have liver or kidney disease, or an overactive thyroid.
- You have bipolar disorder, where antidepressants can trigger a switch to mania.
- You are pregnant or breastfeeding.
- You are older, where confusion, falls, constipation and urinary retention are markedly more likely.
- You take an MAOI, an SSRI, tramadol, a triptan or St John’s wort — combinations affecting serotonin can cause serotonin syndrome.
- You take other sedating or antimuscarinic medicines, including sedating antihistamines.
Follow the dispensing label. This page does not set doses.
Possible cautions and when to ask a pharmacist or doctor
Do not stop abruptly. Stopping suddenly after several weeks causes discontinuation symptoms — nausea, headache, restlessness, disturbed sleep, flu-like feelings, and sometimes vivid dreams. Tapering over weeks under medical guidance avoids this.
Expect dry mouth, drowsiness and constipation. These are the commonest effects and often ease over the first weeks. Blurred vision, dizziness on standing, weight gain and difficulty passing urine also occur.
Overdose is dangerous. Tricyclics are considerably more toxic in overdose than SSRIs, primarily through effects on heart rhythm. Keep them out of reach of children, and treat any suspected overdose as an emergency — go to hospital immediately with the packaging, even if the person seems well.
Mood and thoughts of self-harm. Anyone starting an antidepressant, particularly under 25, should be watched for worsening mood, agitation or thoughts of self-harm in the first weeks. Report these promptly.
Confusion and falls in older adults are a real concern, and lower amounts are used.
Give it a fair trial. Two to six weeks at a steady amount for nerve pain; longer for depression. Stopping at a week is the commonest reason people conclude it did not work.
Seek urgent medical attention for palpitations, an irregular heartbeat or fainting; confusion or hallucinations; a seizure; eye pain with blurred vision or halos; inability to pass urine; agitation with fever, sweating and a racing heart; thoughts of self-harm; or any suspected overdose.
Related medicine guides
Frequently asked questions
What is amitriptyline 10 mg used for? At that amount, almost always nerve pain, migraine prevention, fibromyalgia or sleep — not depression, which requires considerably more.
Why has an antidepressant been prescribed for my pain? Serotonin and noradrenaline carry the body’s own pain-damping signals. Strengthening them reduces nerve pain at amounts far below those used for depression, whether or not you are depressed.
How long before it works? For nerve pain, two to six weeks at a steady amount. Stopping after a week is the commonest reason people think it failed.
Why does it make me so drowsy? It blocks histamine receptors, the same action that makes some antihistamines sedating. Taking it two to three hours before bed reduces morning grogginess.
Can I stop taking it suddenly? No. Taper under medical guidance — stopping abruptly causes nausea, headache, restlessness and disturbed sleep.
Is it addictive? It does not cause dependence in the way benzodiazepines do, but it does cause discontinuation symptoms if stopped abruptly, so it is tapered.