Amitriptyline is an antidepressant medicine. It's used to treat low mood and depression.

This medicine is only available on prescription. It comes as tablets and as a liquid.

Amitriptyline is also used for some types of pain and to prevent migraines. Read about amitriptyline for pain and migraines.

• It can take 4 to 6 weeks for amitriptyline to work.
• Side effects such as a dry mouth and constipation are common. They're usually mild and go away after a couple of weeks.
• Amitriptyline can make you feel sleepy so it's best to take it in the evening or before you go to bed.
• If you and your doctor decide to take you off amitriptyline, your doctor will probably recommend reducing your dose gradually to help prevent extra side effects.
• Amitriptyline is an antidepressant, but at lower doses it's also very good for treating pain and migraine.

Amitriptyline can be taken by most adults. It can also be taken by children aged 16 to 17 years for depression or low mood.

Check with your doctor before starting to take amitriptyline if you:

• have had an allergic reaction to amitriptyline or any other medicine in the past
• have a heart problem - amitriptyline can make some heart problems worse
• have a rare illness called porphyria
• have liver or kidney problems
• have epilepsy or are having electroconvulsive treatment - amitriptyline may increase your risk of having a seizure
• have ever taken any other medicines for depression - some rarely-used antidepressants can interfere with amitriptyline
• are trying to become pregnant, are already pregnant or you are breastfeeding
• have an eye problem called glaucoma - amitriptyline can increase the pressure in your eye
• have thoughts about harming yourself or ending your life

If you have diabetes, amitriptyline can make it more difficult to keep your blood sugar stable. Monitor your blood sugar more often for the first few weeks of treatment with amitriptyline and adjust your diabetes treatment if necessary. Speak to your doctor if your blood sugar levels are causing you concern.

It's usual to take amitriptyline once a day before bedtime because it can make you feel sleepy. If you find that you are still feeling drowsy in the morning you could try taking it earlier in the evening.

Sometimes, when you're just starting treatment, you may be told to take a lower dose 2 or 3 times a day until you get used to the medicine. This is because taking a smaller dose 2 or 3 times a day for a while can reduce the chance of you having side effects.

Amitriptyline doesn't usually upset the stomach so you can take it with or without food.

Swallow the tablet with a drink of water - if you chew it, it tastes bitter.

How much will I take?

Amitriptyline tablets come in different strengths of 10mg, 25mg or 50mg.

Amitriptyline liquid comes in 3 different strengths containing 10mg, 25mg or 50mg of amitriptyline in a 5ml spoonful.

The usual dose of amitriptyline for depression in adults is 50 to 100mg a day. This may go up to 150mg to 200mg a day if you need a stronger dose, but only under the supervision of a hospital specialist.

Children aged 16 to 17 years and older people sometimes start on a lower dose of 25mg to 50mg a day to reduce the chance of side effects.

The maximum dose of amitriptyline is 200mg per day.

What if I forget to take it?

If you take amitriptyline once a day and forget a dose, don't worry. Take your next dose the next day at the usual time.

If you take amitriptyline 2 or 3 times a day and forget a dose, take it as soon as you think about it unless it's close to the time for your next dose.

Never take 2 doses at the same time to make up for a forgotten dose.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

What if I take too much?

The amount of amitriptyline that can lead to an overdose varies from person to person.

Like all medicines, amitriptyline can cause side effects in some people, but many people have no side effects or only minor ones. Some of the common side effects of amitriptyline will gradually improve as your body gets used to it.

Common side effects

Keep taking the medicine but talk to your doctor or pharmacist if these common side effects bother you or don't go away:

• constipation
• dizziness
• dry mouth
• feeling sleepy, tired or weak
• difficulty peeing
• headaches

Serious side effects

It happens rarely, but some people have a serious side effect after taking amitriptyline.

Call a doctor straight away if you get:

• a fast or irregular heartbeat
• yellow skin, or the whites of your eyes go yellow - these can be signs of a liver problem
• constant headaches, long lasting confusion or weakness, frequent muscle cramps - these can all be signs of low sodium levels in your blood. In severe cases low sodium levels can lead to seizures
• thoughts about harming yourself or ending your life
• eye pain, a change in your eyesight, swelling or redness in or around the eye
• severe constipation or you're unable to pee and it's causing severe stomach pain

Call 999 straight away if you experience:

• weakness on one side of your body
• trouble speaking or thinking
• loss of balance or blurred eyesight

These can be signs of a stroke. If you suspect that you or someone else is having a stroke, phone 999 immediately and ask for an ambulance.

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to amitriptyline.

These are not all the side effects of amitriptyline. For a full list see the leaflet inside your medicines packet.

What to do about:

• constipation - eat more high-fibre foods such as fresh fruit and vegetables and cereals. Try to drink several glasses of water or another non-alcoholic liquid every day. If you can, it may also help to do some exercise. Watch a short video on how to treat constipation.
• feeling dizzy - this is probably due to low blood pressure. Drink plenty of water or other non-alcoholic drinks. Do not stand up too quickly after sitting or lying down.
• dry mouth - chew sugar-free gum or sugar-free sweets.
• feeling sleepy or tired - take amitriptyline in the evening and cut down the amount of alcohol you drink. Do not drive or use tools or machinery if you're feeling sleepy. If this doesn't help, talk to your doctor.
• difficulty peeing - relax when you try to pee. Do not try to force the flow of urine. If it doesn't happen, try again later. Talk to your doctor urgently if you can't pee at all.
• headaches - make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Talk to your doctor if the headaches last longer than a week or are severe.

It's important for you and your baby that you stay well during your pregnancy. If you become pregnant while taking amitriptyline speak to your doctor. Do not stop taking your medicine unless your doctor tells you to.

Amitriptyline has been linked to a very small increased risk of problems for your unborn baby. However if your depression is not treated during pregnancy this can also increase the chance of problems.

You may need to take amitriptyline during pregnancy if you need it to remain well. Your doctor can explain the risks and the benefits, and will help you decide which treatment is best for you and your baby.

For more information about how amitriptyline can affect you and your baby during pregnancy, visit the Best Use of Medicines in Pregnancy (BUMPS) website.

Amitriptyline and breastfeeding

If your doctor or health visitor says your baby is healthy, amitriptyline can be used during breastfeeding.

Amitriptyline passes into breast milk in very small amounts. It's unlikely to cause any harm to your baby.

It is important to continue taking amitriptyline to keep you well. Breastfeeding will also benefit both you and your baby.

If you notice that your baby isn't feeding as well as usual, or seems unusually sleepy, or if you have any other concerns about your baby, then talk to your health visitor or doctor as soon as possible.

Many medicines and amitriptyline can interfere with each other and increase the chances of side effects.

Tell your doctor if you have ever taken any other medicines for depression. Some rarely-used antidepressants can interfere with amitriptyline to cause very high blood pressure even after you have stopped taking them.

Make sure that your doctor and pharmacist know you're taking amitriptyline before starting or stopping any other medicine.

Mixing amitriptyline with herbal remedies and supplements

Do not take St John's wort, a herbal remedy for depression, while you're taking amitriptyline as this will increase your risk of side effects.