Amitriptyline

How it works

What does amitriptyline do?

Amitriptyline is a tricyclic antidepressant.

Research suggests that depression is more likely to occur when the brain doesn’t have enough of the brain transmitters serotonin and noradrenaline.

Nerve endings in the brain release these chemicals to act on receptor targets. They are then taken back into the nerve endings in a recycle process.

Tricyclic antidepressants like amitriptyline block these transmitters being taken back up into the brain cells.

This means that more serotonin and noradrenaline are available to act on the receptor targets, which helps treat the symptoms.

How long does amitriptyline take to start working?

You should start to see some positive effects from amitriptyline after two weeks.

Your doctor is likely to increase your dose over the course of a month to find the right level for you.

If you do not feel much better after four weeks, you should go back to your doctor to review your treatment.

How long will I need to take amitriptyline?

You and your doctor should talk about how long you might need to take amitriptyline before you start your treatment.

Many people take amitriptyline for long periods.

If you take amitriptyline for low mood (depression) you will probably need to take it for at least a further six months after you feel well again, otherwise your symptoms are much more likely to come back.

If you have had more than one time when you felt depressed, you may take an antidepressant for up to two years, or even longer, to stop this happening again.

Your doctor needs to know if…

You need to talk to your doctor or pharmacist before starting treatment with amitriptyline if any of the following apply to you:

• you have any blood disorders (you may bruise easily, frequently suffer from infections or be anaemic)
• you have another mental health condition (e.g. schizophrenia or bipolar disorder)
• you have liver or heart disease
• you cannot urinate (go for a wee) easily
• you have an enlarged prostate gland
• you have an overactive thyroid gland and/or you are taking medicines to treat a thyroid disorder
• you have epilepsy
• you are being given electroconvulsive therapy (ECT)
• you have increased pressure in the eye (known as narrow-angle glaucoma)
• you are taking a monoamine oxidase inhibitor (MAOI), another type of antidepressant, or you have taken a MAOI within the previous 14 days for depression - MAOIs include moclobemide, isocarboxazid, phenelzine and tranylcypromine
• you have a problem with your blood called porphyria

Taking amitriptyline

You should only take amitriptyline as agreed with your doctor.

You will get the best from your medicine if you take it regularly, as prescribed.

Make sure that you know your dose. If it's not written on the label, check with your pharmacist or doctor.

You may have to take it more than once a day. Choose times that you can always remember. This could be mealtimes, or when you brush your teeth.

As amitriptyline can make you sleepy, it might be best to take it at nighttime, 30 minutes you go to bed.

If you are having problems because you must take it at school or work, or you are finding it hard to remember to take it more than once a day, talk to your doctor about your dosing schedule.

You can take it before or after food.

Swallow the tablets with a drink of water - if you chew them, they taste bitter.

What if I miss a dose?

If you forget to take a dose, then just take it as soon as possible.

If you forget to take it by your next dose, only take the next dose.

Do not take a double dose.

What will happen if I forget to take my amitriptyline?

If you forget to take your tablets for a few days, you may start getting withdrawal symptoms, including:

• flu-like symptoms (chills, muscle aches, sweating, headaches, feeling sick)
• strange dreams and disturbed sleep
• irritability and restlessness

You should talk to your doctor about these symptoms.

Stopping the use of amitriptyline

Stopping the medication causes the balance of chemicals in the brain to change.

Once you start taking amitriptyline, the brain adjusts to having new levels of serotonin and noradrenaline around.

If you stop taking the amitriptyline all at once, the balance starts to change again.

You could get some withdrawal symptoms from the change, including:

• feeling sick
• headaches
• feeling weak and generally unwell
• feeling very happy or over-excited
• speech problems
• shaking

If you want to stop taking amitriptyline, go to the doctor and they will help you to bring the dose down gradually. This will take a few weeks. You may still get some withdrawal effects, especially during the first two weeks as you reduce the dose. These effects will go away as you carry on reducing the dose. Talk to your doctor if they are uncomfortable and are affecting your life.

The information on this page was reviewed by the College of Mental Health Pharmacy in March 2020.

Safety headlines

If you have taken more amitriptyline than the dosage recommended by the doctor who prescribed it to you, you must get medical help immediately – even if you do not feel any different.

As part of depression, some people think about hurting themselves or taking their own lives. Antidepressant medication will not stop this. You must get some urgent help if you are having these sorts of thoughts. Speak to someone who is looking after you or go straight to hospital with your tablets.

Although rare, amitriptyline can cause serious allergic reactions (difficulty breathing, swelling of your face or throat, itching skin lumps). Go with your medicine to the emergency department (A&E) of the nearest hospital if you get any of these symptoms.

Do not take amitriptyline if you have taken a monoamine oxidase inhibitor antidepressant (MAOI) like moclobemide, phenelzine, isocarboxazid or tranylcypromine in the last 14 days.

Stopping amitriptyline suddenly can cause unpleasant withdrawal effects – if you want to stop, talk to your doctor about how best to do so.

You might feel sleepy in the first few days after taking amitriptyline – do not drive a car, ride a bike or operate machines until you see how this affects you and things settle down.

Use good contraception while you are taking amitriptyline. If you take amitriptyline while you are pregnant, it may affect the developing baby. However, not treating your depression may be worse for both you and your baby, so do talk to your doctor or midwife about this and get their help.

Amitriptyline can also cause symptoms in newborn babies such as extra sleepiness, so your baby will be closely checked. In most cases you should be able to breastfeed as normal.

When to go to the hospital

If you have taken more amitriptyline than the dosage recommended by the doctor who prescribed it to you, you must get medical help immediately – even if you do not feel any different. Go to A&E. Take your medicine with you to show to the doctors. Tell them how much you have taken. Get a friend or family member to go with you if you can, in case you feel ill on the way.

You might get any of the following signs:

• fast or uneven heartbeat
• low blood pressure (feeling dizzy or faint)
• your pupils (black centre part of your eye) going large
• feeling sleepy
• feeling agitated
• being sick
• having fits, or stiffness in your muscles
• going into a coma

You should also stop taking amitriptyline and go to a doctor or hospital straight away if you get any of the following symptoms:

• if you have any thoughts of taking your own life, or of other ways of hurting yourself. This may be part of the depression. Taking antidepressants won’t stop this and you need urgent help. As the depression lifts these thoughts may feel more present. This can happen to anyone, especially people who are under the age of 25
• a skin rash (which may be itchy)
• sensitivity to the sun or sun lamps
• swelling of your face, lips, throat or tongue, which may be severe, causing shortness of breath, shock and collapse – this could mean that you are having an allergic reaction to amitriptyline
• fever or chills
• sore throat, ulcers in your mouth or throat
• unusual tiredness or weakness
• unusual bleeding or unexplained bruises – this could indicate a serious effect on your blood, though this is very rare

When to see your doctor

Tell the doctor if you are going to have an operation – you may need to stop amitriptyline for a few days as it does not mix well with some anaesthetics used in surgery.

You also need to tell the people who are going to do your operation before the day it takes place.

Side effects

Like all medications, amitriptyline has some side effects, and in some cases they can be serious.

However, most side effects are mild and should get better within a few days. If they do not, you should go back to your doctor.

Very common side effects (affecting more than one in ten people) include:

• feeling sleepy
• dry mouth
• blocked nose
• blurred vision
• constipation (finding it difficult to poo)
• nausea (feeling sick)
• weight gain
• excessive sweating
• changes in heart rhythm - you may feel palpitations or a fast heartbeat
• dizziness on standing
• feeling more angry than usual

Other side effects of amitriptyline are much rarer but are included below.

Body

Amitriptyline can have some effects on your body, including:

• breast swelling and milk flow (regardless of gender)
• swelling of the testicles (balls)
• changes in blood sugar levels
• increased appetite and weight gain
• skin rashes
• buzzing or ringing in the ears

Some people experience changes in their blood cells (you may get a sore throat, mouth ulcers and recurring infections, bleeding or bruising easily).

Some people find that amitriptyline affects their brain and central nervous system. Symptoms of this include:

• dizziness or weakness
• tiredness or sleepiness
• headache
• difficulty concentrating
• confusion, anxiety, restlessness, or disorientation (not knowing where you are)
• difficulty sleeping or nightmares
• slight hyperactivity, excitement, or unusual behaviour
• delusions or hallucinations (seeing things that are not there)
• numbness or tingling or pins and needles (particularly in the hands and feet)
• lack of co-ordination
• shaky movements, or tremor
• seizures (fits)
• unconsciousness
• slow or slurred speech

Some people find amitriptyline affects their heart, with symptoms including:

• postural hypotension (feeling faint when you stand up)
• changes in blood pressure
• fast/racing heart, or uneven/slow heartbeat

Some people find amitriptyline affects their liver, with symptoms including:

• hepatitis, including changes in liver function
• jaundice (yellowing of the skin and/or whites of the eyes)

Sleep

Amitriptyline is used to help people sleep better and may cause you to feel very sleepy, as expected. This may be a problem if you continue to feel sleepy during the day as well as at night.

In some people, amitriptyline can cause strange dreams. Talk to your doctor if this happens for more than the first few nights.

Sex and fertility

Sex

Amitriptyline can have side effects that affect your sex life. These include:

• breast growth
• milk flow from the breasts
• swollen testicles or problems getting an erection
• loss of sex drive or not wanting to have sex

If these symptoms don’t pass, and this is a problem for you, go back to the doctor and see what else you could try.

If it works for you, amitriptyline may have a positive effect on your sex life as your mood lifts, your sleep gets better and you can concentrate on your relationships.

Fertility

There is no information available about whether amitriptyline can affect fertility, but it is unlikely to be a problem.

If you are trying to get pregnant while taking amitriptyline, talk to your doctor.

Pregnancy, post-natal and breastfeeding

Pregnancy

If you find you are pregnant while doing well on amitriptyline, it is probably best to stay on it. Talk to your doctor as soon as you can about your options.

Post-natal

Some newborn babies whose mothers take amitriptyline during pregnancy can get withdrawal symptoms at birth and soon after, like breathing problems or restlessness.

Tell your midwife if you are taking amitriptyline, so that they can help if the baby has any symptoms after birth.

Breastfeeding

Amitriptyline is passed to the baby in breastmilk in small amounts.

Breastfeeding can help offset some of the withdrawal effects of amitriptyline, if they happen.

Talk to your doctor or midwife about the benefits and risks of breastfeeding while taking amitriptyline.

Driving and transport

Do not drive a car or ride a bike just after you start taking amitriptyline.

Taking amitriptyline may make you feel less alert than normal and/or give you blurred eyesight when you start taking it. This could affect you if you drive a car, ride a bike, or do anything else that needs a lot of focus. It might be best to stop doing these things for the first few days, until you know how it affects you.

Do not worry - most people drive as normal while taking amitriptyline.

School and exams

Try not to take amitriptyline for the first time just before your exams.

Amitriptyline may affect your concentration, give you blurred eyesight and make you feel dizzy and tired.

You should talk to your doctor about any future exams if you are starting amitriptyline. You might decide together to delay starting it until you have done them.

If they are more than a month away, however, you might find that it is better to start amitriptyline to improve your sleep and your motivation to study.

Do not worry - most people take exams as normal while taking amitriptyline.

Friends and family

You may want to let your family and friends know you are taking amitriptyline so they can support you and help you look out for side effects.

For guidance on this, check out our page on getting support with your medication.

Sport

Amitriptyline is not a banned substance in sport.

If amitriptyline affects your concentration, eyesight or co-ordination, then you may want to wait to see if those effects go away before playing sports that need a lot of focus.

Do not worry - most people play sports as normal while taking amitriptyline.

Amitriptyline can produce a false positive result in some drug tests, including urine tests for LSD. Talk to your doctor about this if it is a problem for you.

Alcohol, street drugs and smoking

Alcohol

If you drink alcohol while taking amitriptyline, it may make you very sleepy. It will also make you less alert when doing things that need focus, like driving.

If you want to drink alcohol, remember that you might be sleepy and make sure you can get home safely.

Do not drive or use machines, even on the day after you had a drink. Do not put yourself or others in danger.

Street drugs

Amitriptyline does not mix well with recreational drugs.

If you mix cannabis and amitriptyline, you could get a fast heartbeat.

Cannabis and other drugs may have their own side effects on your mental health, like anxiety or psychosis. For more information, have a look at our drugs and alcohol page.

If you take heroin or methadone with amitriptyline, you may feel extremely sleepy.

You could get an irregular and dangerous heartbeat if you take amitriptyline with cocaine, amfetamines, ecstasy, MDA or 6-APB.

Smoking

Cigarette smoke affects the amount of amitriptyline in your body.

If you start or stop smoking while you are taking amitriptyline, you may have to change your dose. Tell your doctor as soon as possible if this is the case.

Prescription medicines 

If you are taking other medicines, amitriptyline may affect how well they work or may cause side effects. Tell your doctor about these before you start your treatment.

Talk to your pharmacist if you buy any medications over the counter to treat common illnesses like colds and flu or topical applications that you put on your skin.

Other interactions

Amitriptyline tablets may not be suitable for you if you have problems eating some sugars or dairy (milk-based) foods. If you are lactose intolerant, get advice from your local pharmacist.

Some ingredients are added to amitriptyline to make it either a liquid or a tablet. Sugars, colourings, preservatives and flavourings do not cause any problems for most people.

References and further reading

For more helpful links and information, have a look at our references and further reading page.