Amitriptyline: what it is used for, amitriptyline for sleep and side effects

Amitriptyline is an antidepressant in the tricyclic antidepressant class. It comes as tablets, is sold as a generic and needs a prescription. It used to be sold under the brand name Elavil, which MedlinePlus lists as no longer on the market.

Amitriptyline is not a controlled substance: it does not appear on the DEA list of controlled substances. It is still a medicine with real side effects and important warnings, and it should be used under medical supervision.

According to its FDA label, amitriptyline is indicated for the relief of symptoms of depression. That is its only approved use. The label does not recommend it under age 12, and MedlinePlus says people under 18 should not normally take it, although a doctor may decide it is the best option in some cases. For the condition itself, read depression.

According to MedlinePlus, doctors also prescribe it for uses that are not on the label (off-label): preventing migraine headaches, the long-lasting nerve pain that can follow shingles, and eating disorders. Off-label is not forbidden, but it means the FDA did not evaluate the medicine for that purpose.

According to its label, amitriptyline blocks the reuptake of two brain chemical messengers, norepinephrine and serotonin, which prolongs their action. That is believed to explain its antidepressant effect, although the label notes that its exact mechanism is not known. The label describes it as an antidepressant with sedative effects, which is why it makes you sleepy.

Migraine. The 2012 American Academy of Neurology and American Headache Society guideline on preventing episodic migraine in adults rated amitriptyline Level B: "probably effective," a medicine that should be considered to prevent attacks. It is a preventive use, not a treatment for a headache that has already started. Read more about migraine.

Nerve pain. The UK NICE guideline on neuropathic pain in adults recommends offering a choice of amitriptyline, duloxetine, gabapentin or pregabalin as initial treatment for neuropathic pain (except trigeminal neuralgia). MedlinePlus also lists nerve pain after shingles. If you have numbness and tingling, for example from diabetes, the doctor first works out the cause.

The FDA label gives no dose for these uses, and neither does this page. The doctor decides the dose after evaluating you and reviewing your other medicines.

Amitriptyline makes you sleepy: its label describes it as an antidepressant with sedative effects and says that effect may show up before the effect on mood. That is why many people know it as a sleeping pill, even though that use is not FDA-approved.

A 2018 Cochrane review of antidepressants for insomnia in adults found no studies of amitriptyline for sleep, even though it is commonly prescribed for it, so there is no trial evidence for that use.

If your problem is that you cannot sleep, read our page on insomnia. This page gives no dose for sleep: the doctor decides whether any medicine is appropriate after evaluating you.

The doctor decides the dose. The FDA label gives ranges only for depression. For adults who are not hospitalized, it suggests starting at 75 mg a day in divided doses and, if needed, going up to 150 mg a day; another approach is to start with 50 to 100 mg at bedtime. The usual maintenance dose is 50 to 100 mg a day. For teens and older adults, the label recommends lower doses.

How long it takes. Per the label, the full effect on depression can take up to 30 days, and MedlinePlus says it may take a few weeks or longer. Per MedlinePlus, it is taken one to four times a day, at about the same times each day. Do not change your dose on your own.

According to MedlinePlus and the FDA label, common amitriptyline side effects include:

Boxed warning: suicidal thoughts under age 25. The FDA label warns that antidepressants increased the risk of suicidal thoughts and behavior in children, teenagers and young adults aged 18 to 24, especially in the first months and when the dose changes. At any age, you and your family should watch for changes in mood or behavior. If thoughts of harming yourself appear, call Línea PAS at 1-800-981-0023 or 988.

Heart. The label warns that tricyclic antidepressants, especially at high doses, can cause arrhythmias, a fast heartbeat and changes in the heart's electrical conduction. People with heart disease should be watched closely.

Anticholinergic effects. It can cause dry mouth, constipation, urinary retention and blurred vision. In people with narrow eye angles it can trigger an attack of angle-closure glaucoma: eye pain, vision changes, or a red, swollen eye are an emergency.

Drowsiness and driving. It can affect your ability to drive or operate machinery. Do not drive until you know how it affects you.

Low sodium. It can lower blood sodium, with headache, confusion, weakness or unsteadiness. The risk is higher in older adults and people taking diuretics.

Mania. In people with bipolar disorder it can trigger mania or hypomania, which is why the doctor asks about that history before starting.

Older adults. The label says older adults are more sensitive to its anticholinergic effects (confusion, sedation, constipation) and at higher risk of falls. MedlinePlus says older adults should not usually take it, because safer options exist for the same conditions.

Overdose. Per the label, an overdose of this class of medicines can be fatal. Keep it in its container, tightly closed and out of reach of children, as MedlinePlus advises. If someone takes too much, call Poison Help at 1-800-222-1222; if they collapse, have a seizure, have trouble breathing or cannot be woken, call 911.

Not used (label contraindications): if you have had an allergic reaction to amitriptyline; together with MAO inhibitors (MAOIs) or within 14 days of stopping one; with cisapride, because of the risk of QT prolongation and arrhythmia; or during the acute recovery phase after a heart attack.

Serotonin syndrome. Combined with other medicines that raise serotonin (triptans for migraine, other antidepressants, tramadol, fentanyl, lithium, buspirone, tryptophan or St. John's wort), it can cause agitation, fever, sweating, tremor and stiffness. It is an emergency.

CYP2D6 inhibitors. Some medicines slow the enzyme that clears amitriptyline and can raise its blood level sharply: for example fluoxetine (Prozac), sertraline, paroxetine, quinidine and cimetidine. The label says to allow at least 5 weeks after stopping fluoxetine before starting a tricyclic.

Alcohol and sedatives. Amitriptyline can enhance the effects of alcohol, barbiturates and other sedatives. MedlinePlus says alcohol adds to the drowsiness it causes. Ask the doctor before combining it with alcohol or another medicine, and tell her every medicine and supplement you take.

If you are pregnant, planning a pregnancy or breastfeeding, the decision is made with the doctor. Per the FDA label, amitriptyline crosses the placenta, there are no adequate studies in pregnant women, and it is used in pregnancy only if the benefit justifies the risk. It also passes into breast milk: the label asks for a decision between stopping nursing or stopping the medicine, and MedlinePlus says not to breastfeed while taking it. If you become pregnant, do not stop it on your own: talk with the doctor first.

Do not stop taking amitriptyline without talking to your doctor. Per the label, stopping suddenly after long use can cause nausea, headache and a general unwell feeling, and the label notes these symptoms do not mean addiction. The usual approach is to lower the dose gradually, as the doctor directs.

Amitriptyline is a tricyclic antidepressant; duloxetine is a serotonin and norepinephrine reuptake inhibitor (SNRI). According to MedlinePlus, duloxetine is used for depression, generalized anxiety disorder, pain from diabetic nerve damage, fibromyalgia and ongoing bone or muscle pain, while amitriptyline's only approved use is relieving depression. The NICE guideline lists both among the initial options for nerve pain. Neither is "best" for everyone: the doctor chooses with you based on your symptoms, your health and your other medicines. Read the guide on duloxetine and venlafaxine.