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.