Nortriptyline is a medicine used for treating nerve pain.

Occasionally, it's also used to treat depression and bedwetting in children (nocturnal enuresis) .

Nortriptyline is available on prescription. It comes as tablets.

• If you take nortriptyline to treat nerve pain, it usually takes a week or so for pain to begin to wear off.
• If you take it for depression, it can take 4 to 6 weeks until it reaches full effect.
• Common side effects include a dry mouth and constipation. They're usually mild and go away after a couple of weeks.
• Nortriptyline can make you feel sleepy so it's best to take it in the evening or before you go to bed.
• If your doctor decides to take you off nortriptyline, they will reduce your dose gradually to help prevent withdrawal side effects such as muscle pain or feeling sick or tired.

Most adults can take nortriptyline. Teenagers aged 12 to 17 years can take it for depression.

Children aged 6 to 17 years old can also take it for bedwetting but other medicines are used first which have less side effects.

Nortriptyline is not suitable for some people. Check with your doctor before starting to take nortriptyline if you:

• have ever had an allergic reaction to nortriptyline or any other medicine
• have a heart problem – nortriptyline can make some heart problems worse
• have liver or kidney problems
• have epilepsy or are having electroconvulsive treatment (ECT) – nortriptyline can increase your risk of seizures or fits
• have ever taken any medicines for depression – some antidepressants can affect the way nortriptyline works, even after you've stopped taking them
• are pregnant, trying to get pregnant or breastfeeding
• have glaucoma – nortriptyline can increase the pressure in your eye
• have thoughts about harming yourself or ending your life
• have type 1 or type 2 diabetes – if you have diabetes, nortriptyline may affect your blood sugar levels. If you usually test your blood sugar level, you may have to do this more often for the first few weeks of treatment. Talk to your diabetes nurse or doctor if the reading is high or low

You'll usually take nortriptyline once a day. If you take it once a day, it's best to take it before you go to bed as it can make you feel sleepy. If you find that it's affecting your sleep, you could try taking it earlier in the evening.

This medicine does not usually upset your stomach. You can take it with or without food.

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

Dosage and strength

Nortriptyline tablets come in 3 different strengths, 10mg, 25mg or 50mg.

The usual dose to treat nerve pain in adults is 10mg a day. This can be increased if necessary. The maximum dose of nortriptyline for treating pain is 75mg a day, but this is only under the supervision of a pain specialist.

For depression in adults, the dose is increased gradually to between 75mg and 100mg a day. It can be increased to a maximum dose of 150mg a day if a specialist prescribes it.

For depression in teenagers (12 to 17 years), the dose is usually increased gradually to 30mg to 50mg a day, but higher doses may be needed.

What if I forget to take it?

If you forget a dose, take it as soon as you remember, unless it's nearly time for your next dose. In this case, just leave out the missed dose and take your next dose at the usual time.

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?

Like all medicines, nortriptyline 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 nortriptyline will gradually improve as your body gets used to the medicine.

Common side effects

Doses of nortriptyline for pain are lower than the doses for depression. This means the common side effects tend to be milder and go away within a few days.

Keep taking the medicine but talk to your doctor or pharmacist if these side effects bother you or do not go away:

• constipation
• feeling dizzy
• dry mouth
• feeling sleepy
• difficulty peeing
• headaches

Serious side effects

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

Contact a doctor if:

• your heartbeat becomes fast and irregular
• the whites of your eyes turn yellow, or your skin turns yellow, although this may be less obvious on brown or black skin – these can be signs of a liver problem
• you have a headache that does not get better, feel confused or weak and have muscle cramps – together these can be signs of low sodium levels in your blood
• you have thoughts about harming yourself or ending your life
• you have eye pain, a change in your eyesight, or swelling or redness in or around the eye
• you have constipation that lasts a long time or problems peeing which are causing stomach ache

What to do about:

• constipation – get more fibre into your diet such as fresh fruit, vegetables and cereals. Try to drink several glasses of water or squash every day. If you can, it may also help to increase your level of exercise.
• feeling dizzy – this is probably due to low blood pressure. Drink plenty of water or squash. Do not stand up too quickly after you've been sitting or lying down. Do not drive, cycle or use tools or machinery until this feeling passes. It's best not to drink alcohol until you see how the medicine affects you.
• dry mouth – chew sugar-free gum or have some sugar-free sweets.
• feeling sleepy – take nortriptyline in the evening. It's best not to drink alcohol until you see how the medicine affects you. Do not drive, cycle or use tools or machinery while you're feeling sleepy.
• difficulty peeing – try to relax when you pee. Do not try to force the flow of urine. If it does not happen, try again later. Talk to your doctor urgently if you cannot pee at all.
• headaches – make sure you rest and drink plenty of fluids. It's best not to drink alcohol until you see how the medicine affects you. Try taking paracetamol or ibuprofen if you need pain relief. Talk to your doctor if the headaches last longer than a few days or are severe.

You may be advised to continue taking nortriptyline during pregnancy, especially if you take it to treat depression.

Speak to your doctor if you become pregnant while taking nortriptyline. Do not stop taking your medicine unless your doctor tells you to.

Your doctor can explain the risks and benefits of taking nortriptyline and will help you choose the best treatment for you and your baby.

Nortriptyline and breastfeeding

If your doctor or health visitor says your baby is healthy, you can use nortriptyline while breastfeeding.

Notriptyline passes into breast milk in very small amounts so it's unlikely to cause any harm to your baby.

If you are being treated for depression it's important to continue taking nortriptyline to keep you well. Breastfeeding will also benefit both you and your baby.

If you notice that your baby is not 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.

For more information about how nortriptyline can affect you and your baby during pregnancy, read this leaflet on the Best Use of Medicines in Pregnancy (BUMPs) website.

Many medicines taken with nortriptyline can affect each other and increase the chance of side effects.

Always check with your doctor or a pharmacist before starting any new medicine while you are taking nortriptyline.

Taking opioid-based medicines, like codeine, morphine or oxycodone, together with nortriptyline can increase your risk of becoming very drowsy and having breathing problems.

Tell your doctor if you have ever taken any medicines for depression. Some antidepressants can affect the way nortriptyline works and cause very high blood pressure. This can happen even after you have stopped taking them.

Mixing nortriptyline with herbal remedies and supplements

Do not take St John's wort, the herbal remedy for depression, while you are being treated with nortriptyline. It will increase your risk of side effects.

There's very little information about taking nortriptyline with other herbal remedies and supplements. They are not tested in the same way as medicines.