What is amitriptyline?

Amitriptyline (a-muh-trip-tuh-leen) is a drug that can reduce your pain and discomfort, and help you get a good night’s sleep.

You can discuss the benefits and risks of taking amitriptyline with healthcare professionals before you start treatment, so you’re able to make an informed decision.

Amitriptyline is a type of drug called a tricyclic antidepressant. These drugs were originally developed to treat anxiety and depression, but when taken at a low dose they can reduce or stop pain.

Amitriptyline works by increasing the amount of serotonin your brain makes. Serotonin is a chemical, called a neurotransmitter, that the brain sends out to nerves in the body. It’s thought to improve your mood, emotional state, sleep and the way your body responds to pain.

By raising your serotonin levels, amitriptyline should change your body’s reaction to pain. The low dose won’t treat depression, but it should reduce your pain, relax your muscles and improve your sleep.

It’s safe to be prescribed to adults or children. It should help you sleep as soon as you start taking it, but significant changes to your pain and mood can take up to six weeks.

Amitriptyline is prescribed for many painful, long-term conditions that affect your muscles or bones. These include:

  • arthritis (arth-rye-tus)
  • back pain
  • fibromyalgia (fie-bruh-my-al-juh)
  • tension headaches and migraines
  • damage to nerve endings in limbs, which may be described to you as peripheral neuropathy (pe-rif-er-ul new-ro-pa-thee).

You may not be able to take amitriptyline if:

  • you’ve had an allergic reaction to a medication in the past
  • you have heart problems, as it can make them worse
  • you have uncontrolled bipolar disorder
  • you have the rare inherent blood disorder porphyria (por-fear-ee-ya) which affects the nervous system
  • you have liver or kidney problems
  • you have epilepsy, as it can increase the risk of seizures
  • you’ve had or are having treatment for depression, as some medicines can interact badly with it
  • you have glaucoma (glor-co-ma), as it can increase the pressure in your eye
  • you have extreme mood swings, thoughts of self-harming or suicide.

If you’re pregnant, breastfeeding, or want to try for a baby, you may be prescribed another medicine instead of amitriptyline.

How is it taken?

Amitriptyline can be prescribed as a tablet or liquid. You’ll need to take it every day an hour or two before your usual bedtime, as it can make you sleepy. If you find you’re still feeling sleepy when you wake in the morning, try taking it earlier in the evening.

Amitriptyline is taken at lower doses for pain relief than when it's used for depression. Your doctor will usually start you on the lowest dose possible and may increase it if you're still experiencing pain after several weeks. Doses for children aged under 12 are worked out according to their weight and symptoms. It can take up to six weeks for you to see the benefits, so try to stick with it.

You’ll probably take it for as long as it helps your condition. Some people take it for many months, even years, without having any negative effects.

It isn’t an addictive medication, but you may get unpleasant side effects if you suddenly stop taking it. You should talk to your doctor before making any changes to your treatment. They’ll probably recommend that you reduce the dose slowly over several weeks or more, depending on how long you’ve been taking it.

What if I forget to take it?

Try to take your missed dose as soon as you remember – unless it’s almost time for your next dose, or you are going to be driving, cycling or using machinery. In these cases, leave out the missed dose and take your next one as usual.

Never take two doses at the same time, or take an extra dose, to make up for a missed one.

If you are having problems remembering when to take your medication, try setting an alarm to remind yourself.

What if I take too much?

Taking more than your prescribed dose can cause potentially serious symptoms and side effects, such as:

  • vomiting
  • shaking
  • drowsiness
  • changes to your heartbeat
  • seizures.

If you think you’ve taken too much amitriptyline, you must contact your doctor or a healthcare professional immediately for advice.

Side-effects and risks

Many people take amitriptyline without experiencing any problems - but, like any medication, it can cause side effects. Many of the more common ones go, once your body has adjusted to the treatment.

If they trouble you or don’t improve over the first few weeks of taking it, speak to your doctor or pharmacist.

Common side effects include:

  • constipation
  • dizziness
  • dry mouth
  • feeling sleepy
  • difficulty weeing
  • headache.

Some people also find their appetite and weight changes when they start taking it. Talk to your doctor or pharmacist if your weight changes worry you.

Because amitriptyline can make you drowsy, you should not cycle, drive or use machinery for the first few days of taking it, until you know how it affects you.

It may also be best to try it out when you don’t have to get up for work the next day.

In rare cases, people can have serious side effects. Get medical help straight away if you experience:

  • weakness on one side of your body
  • blurred eyesight
  • trouble speaking, thinking or balancing.

These could be signs of a stroke and you need to call 999 to ask for an ambulance.

Other rare side effects, you should tell a doctor about urgently, include:

  • a fast or irregular heart beat
  • yellowing of the skin or the whites of your eyes – these can be signs of liver problems
  • a headache, confusion, muscle cramps, generally feel weak or experience a seizure – these can be signs of low sodium levels in your blood
  • low blood pressure
  • thoughts of hurting yourself in any way
  • eye pain, changes in your sight, swelling or redness in or around your eye
  • severe constipation or you feel unable to wee and you’re in pain.

Allergic reactions

As with any medication, there is a very small risk you may be allergic to it. You should contact a doctor immediately if:

  • you suddenly get a rash – your skin may become itchy, red, swollen, blistered or begin to peel
  • you begin to wheeze
  • feel a tightness across your chest or throat
  • you’re having trouble breathing or talking
  • your mouth, lips, tongue, face or throat become swollen.

These are symptoms of a serious allergic reaction and you must seek medical help straight away.

Other conditions it may affect

  • Diabetes - it can affect your blood sugar levels, so you should check your blood sugar more often for the first few weeks. If your levels become too high or too low, talk to your diabetes doctor.
  • Epilepsy – it can make you more likely to have seizures.
  • Heart problems – it can make some conditions worse.
  • Glaucoma – it can affect the pressure in your eye and you’d need regular eye tests.
  • Overactive thyroid gland.
  • Severe liver disease.
  • Depression – it can react with MAOI antidepressant drugs (monoamine oxidase inhibitors).

Effects on other treatments

Amitriptyline is safe to take with most other drugs prescribed for your condition, but some may interact with it. Always check with the doctor or healthcare professional you’re seeing to make sure any new medication is safe to take with amitriptyline.

  • Painkillers, such as codeine or tramadol, could react with it to make you sleepy and less alert.
  • Antidepressants – some antidepressant treatments, such as serotonin re-uptake inhibitors (SSRIs) or MAOI drugs, can interfere with it, causing high blood pressure or heart problems.

Herbal remedies and supplements, especially St John’s wort, can increase your risk of side effects. Don’t take herbal remedies or supplements without first talking to your healthcare team.

It’s important you tell your doctor about any medications, vitamins, supplements, over-the-counter drugs or herbal treatments you’re using before you start or while you’re taking amitriptyline.

You should also tell them if any existing treatment is being stopped while you’re taking amitriptyline.


Amitriptyline shouldn’t interfere with any vaccinations - just make sure the healthcare professional treating you knows that you’re taking it.


You can drink alcohol while you’re taking amitriptyline but it could make you feel drowsy. It’s best not to drink while you’re getting used to the medication and work out how it affects you.

Alcohol and amitriptyline can also interact to cause high blood pressure.

Recreational drugs

Amitriptyline hasn’t been properly tested when taken with recreational drugs, but some drugs are known to react with it.

Cannabis can make you feel very sleepy and can also make your heart beat very fast.

Drugs with potentially dangerous interactions include:

  • methadone
  • stimulants like MDMA, ecstasy or cocaine
  • hallucinogens like LSD
  • novel psychoactive substances – the new term for ‘legal highs’ – like mephedrone.

Speak to your doctor before starting amitriptyline if you use a recreational drug that may interact with it.

Fertility, pregnancy and breastfeeding

Amitriptyline doesn’t affect fertility. However, some people have been known to experience sex-related problems early in their treatment, such as:

  • men and women having swollen breasts
  • women having some vaginal bleeding
  • men having erectile and ejaculation problems.

These are quite uncommon and should settle down after the first few weeks of treatment. If they don’t, and this concerns you, speak to your doctor to see if another drug may work better.

Post-menopausal women should contact their doctor as soon as possible if they experience any vaginal bleeding.

Amitriptyline doesn’t affect any type of contraception, including contraceptive pills and the morning after pill. If you are pregnant, amitriptyline will only be recommended if your doctor thinks you’ll benefit from taking it. If they don’t think it’s right for you, they will suggest another treatment.

It has been linked to a small risk of problems for unborn babies when it’s been taken in early or late pregnancy. Some babies exposed to the drug during the last three months of pregnancy have also shown withdrawal symptoms.

Like a lot of drugs, your doctor will compare the benefits and risks before prescribing it.

Do speak to your doctor if you become pregnant, or want to try for a baby, while on amitriptyline. Don’t stop taking amitriptyline suddenly or without speaking to your doctor first.

Breastfeeding while taking amitriptyline is unlikely to be harmful to your baby, as the amount of the drug that passes into breastmilk is very small. However, it’s advisable to speak to your doctor first if you do want to breastfeed.