Amitriptyline: what it treats, how to take it, side effects
Last updated September 3, 2026.
Amitriptyline is a tricyclic antidepressant, one of the oldest - and still prescribed for depression, nerve pain, and migraine prevention. It works by increasing certain natural substances in the brain needed for mental balance. Like all antidepressants, it carries the boxed warning about suicidal thinking in young people.
What does it treat?
Depression is the labeled use. MedlinePlus also lists eating disorders, post-herpetic neuralgia (the burning pain that lingers after shingles), and migraine prevention as other uses. The pain and migraine doses are typically lower than the depression doses.
How do you take it?
One to four times a day, same times every day. The label starts outpatients low and increases gradually - 75 mg a day in divided doses is usually satisfactory, up to 150 mg if needed, and an alternative start is 50 to 100 mg at bedtime since the sedative effect arrives before the antidepressant one. Patience is mandatory: a full therapeutic effect can take as long as 30 days. Do not stop suddenly - withdrawal brings nausea, headache, and lack of energy, so your doctor tapers the dose gradually. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: nausea, vomiting, drowsiness, weakness or tiredness, nightmares, headaches, dry mouth, constipation, difficulty urinating, blurred vision, tingling in hands or feet, changes in sex drive or ability, excessive sweating, appetite or weight changes, confusion, and unsteadiness.
- Serious: slow or difficult speech, dizziness or faintness, weakness or numbness of an arm or leg, crushing chest pain, rapid, pounding, or irregular heartbeat, severe skin rash or hives, swelling of the face and tongue, yellowing skin or eyes, jaw, neck, and back muscle spasms, uncontrollable shaking, fainting, and unusual bleeding or bruising - call your doctor immediately. And the boxed warning: a small number of children, teenagers, and young adults up to 24 became suicidal on antidepressants; mental health can change in unexpected ways at any age, especially at the start and at dose changes. Watch for new or worsening depression, thoughts of self-harm, extreme worry, agitation, panic attacks, insomnia, aggression, impulsivity, severe restlessness, or frenzied excitement.
Who should not take it?
Anyone who has taken an MAO inhibitor within the past two weeks, and anyone who recently had a heart attack - MedlinePlus says your doctor will probably rule it out in both cases. Children under 18 should not normally take it. Adults 65 and older should usually not take it, because it is not as safe or effective as alternatives. Flag glaucoma, an enlarged prostate, difficulty urinating, seizures, an overactive thyroid, diabetes, schizophrenia, and liver, kidney, or heart disease. OTC allergy medications and cimetidine interact. Do not breastfeed while taking it; if you become pregnant, call your doctor. Drowsiness is expected - no driving until you know how it affects you, and alcohol adds to the drowsiness.
When is it an emergency?
Call 911 for crushing chest pain, fainting, facial or tongue swelling, or trouble breathing. Thoughts of harming or killing yourself mean calling your doctor right away - or call or text 988, the Suicide and Crisis Lifeline, any time. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
Is amitriptyline only for depression?
No. MedlinePlus lists post-herpetic neuralgia (burning pain after shingles), migraine prevention, and eating disorders among its other uses, and pain and migraine doses often run lower than depression doses. It is one of the oldest antidepressants, which is exactly why its side effect map is so well drawn.
How long does amitriptyline take to work?
Longer than people expect. The label says a sedative effect may appear before the antidepressant effect, but an adequate therapeutic effect may take as long as 30 days. MedlinePlus says a few weeks or longer for the full benefit. Judge it at the one-month mark, not the one-week mark.
Can I drink alcohol while taking amitriptyline?
MedlinePlus's guidance: remember that alcohol can add to the drowsiness caused by this medication - and the precautions tell you to disclose heavy alcohol use to your doctor. Between sedation, unsteadiness, and the judgment effects, the practical answer is avoid it, especially while your dose is still being set.
Why can't older adults usually take amitriptyline?
MedlinePlus says it directly: adults 65 and older should usually not take amitriptyline because it is not as safe or effective as other medications for the same condition. The anticholinergic load - dry mouth, constipation, confusion, urinary trouble, unsteadiness - hits older bodies harder and raises fall risk.
What is the suicide warning about?
The antidepressant class warning. MedlinePlus says a small number of children, teenagers, and young adults up to 24 became suicidal on antidepressants in studies, and that mental health can change in unexpected ways at any age - especially at the start of treatment and at dose changes. Watch for new or worsening depression, agitation, panic, insomnia, impulsivity, and any talk of self-harm, and call the doctor right away if they appear.
Can I stop amitriptyline once I feel better?
Not on your own. MedlinePlus warns that suddenly stopping can cause withdrawal symptoms - nausea, headache, lack of energy - and your doctor will decrease the dose gradually. Feeling better is the medication working, not proof you are done with it.