Amitriptyline

Sounds like 'A-mi-TRIP-ti-leen'

Easy-to-read medicine information about amitriptyline – what it is, how to take amitriptyline safely and possible side effects.

Type of medicine Also called
  • Antidepressant
  • Belongs to a group of medicines known as tricyclic antidepressants (TCAs) or tricyclics
  • Arrow-Amitriptyline®
  • Amirol®

What is amitriptyline?

Amitriptyline has many uses. It is used to treat certain kinds of nerve pain (such as neuropathic pain, peripheral neuropathy, postherpetic neuralgia) and prevent migraine headaches. Amitriptyline belongs to a group of medicines called tricyclic antidepressants. In the past, these medicines were commonly used for depression, but these days doctors usually prescribe newer classes of antidepressants. Tricyclic antidepressants are used for severe depression or when other antidepressants are unsuitable. Read more about antidepressants.

In New Zealand amitriptyline is available as tablets in different strengths - 10 mg, 25 mg and 50 mg.

Dose

  • The dose of amitriptyline will be different for different people.
  • Your doctor will usually start you on a low dose and increase this slowly. This allows your body to get used to the medicine and reduces side effects.
  • Amitriptyline is usually prescribed as a single dose to be taken at bedtime, although your dose may be different.
  • Always take your amitriptyline exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much amitriptyline to take, how often to take it, and any special instructions.
  • If your tablets look different to your last supply, ask your doctor or pharmacist for advice.

How to take amitriptyline

  • Take amitriptyline at the same times each day. It is usually taken as a single dose at bedtime, but your dose may be different.
  • Swallow your amitriptyline tablets with a glass of water.
  • You can take amitriptyline with or without food.
  • If you forget to take your dose, take it as soon as you remember that day. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.
  • Keep taking amitriptyline every day. It may take a few weeks before you notice the full benefits of amitriptyline.
  • If you think amitriptyline is not working for you, do not stop taking it suddenly; speak to your doctor or nurse before stopping.

Precautions – before starting amitriptyline

  • Have you recently had a heart attack?
  • Do you have problems with your heart rhythm?
  • Do you have diabetes?
  • Do you have problems with your liver?
  • Do you have problems with your thyroid?
  • Do you have bipolar disorder?
  • Do you have epilepsy?
  • Do you have problems passing urine or problems with your prostate?
  • Do you have problems with constipation?
  • Are you pregnant or breastfeeding?
  • Are you taking any other medicines, including medicines you can buy without a prescription, such as herbal and complementary medicines?

If any of these apply, it’s important that you tell your doctor or pharmacist before you start amitriptyline. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Precautions – while taking amitriptyline

  • Alcohol: avoid alcohol while you are taking amitriptyline, especially when you first start treatment. Drinking alcohol while taking amitriptyline can cause drowsiness and affect concentration, putting you at risk of falls and other accidents. It can also cause agitation, aggression and forgetfulness. If you do drink alcohol, drink only small amounts and see how you feel. Do not stop taking your medication.
  • Diabetes: if you have diabetes, you may need to check your blood glucose more often because amitriptyline can affect the levels of glucose in your blood. 
  • Sun protection: amitriptyline can make your skin more sensitive to the sun. You may get a burning, tingling feeling on your skin when you are in the sun, or you may notice a darker tan or redness. When outside, protect your skin by using an SPF30+ sunscreen and clothing that protects you from the sun. Let your doctor know if you notice a rash when you first start taking amitriptyline. This could be an allergic reaction.

Possible side effects

Like all medicines, amitriptyline can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Suicidal behaviour

The use of antidepressants has been linked with self-harm or suicidal thoughts and behaviour. Children, teenagers, young adults and people with a history of suicidal behaviour are most at risk. This is most likely during the first few weeks of starting treatment or if the dose is changed. It is important to look out for signs of suicidal behaviour such as suicidal thoughts, self-harm, worsening of low mood, agitation or aggression.

If you notice any of these signs, contact your doctor immediately. If you need urgent help or are concerned, phone:

  • Lifeline 0800 543 354 (available 24/7), or
  • Healthline 0800 611 116, who can give you the phone number for your local mental health crisis line.

Other side effects

Side effects What should I do?
  • Feeling sleepy, drowsy, or tired
  • These are quite common when you first start taking amitriptyline and usually goes away with time
  • It may be best to take amitriptyline at bedtime
  • Be careful when driving or using tools until you know how this medicine affects you
  • These effects put you at risk of falls, and injuries especially if you are elderly. Tell your doctor if you are concerned
  • Do not drink alcohol
  • Feeling dizzy, faint or lightheaded
  • Get up slowly when rising from a sitting or lying position
  • These effects put you at risk of falls, and injuries especially if you are elderly. Tell your doctor if you are concerned
  • Dry mouth
  • Constipation
  • Sore mouth
  • Anxiety or restlessness
  • These are quite common 
  • Read more for advice on managing dry mouth and constipation
  • Tell your doctor 
  • Suicidal thoughts, thoughts of harming yourself, or worsening depression
  • Tell your doctor immediately or ring HealthLine 0800 611 116
  • Signs of an allergic reaction such as skin rash
  • Tell your doctor immediately or ring HealthLine 0800 611 116
  • Signs of serotonin syndrome such as feeling agitated and restless, heavy sweating, shivering, fast heart rate or irregular heartbeat, headache, diarrhoea and rigid or twitching muscles
  • You are at increased risk of serotonin syndrome if you recently started
    taking amitriptyline or recently increased the dose
  • Tell your doctor immediately or ring HealthLine 0800 611 116

Interactions

Amitriptyline interacts with many other medications and herbal supplements (such as St. John's Wort) so check with your doctor or pharmacist before starting amitriptyline or before starting any new medicines.

Learn more

The following links have more information on amitriptyline.

Medsafe Consumer Information Sheets: Arrow-Amitriptyline 
New Zealand Formulary Patient Information: Amitriptyline

References

  1. Amitriptyline hydrochloride New Zealand Formulary
  2. Diagnosing and managing headache in adults in primary care BPAC, 2017
  3. The role of medicines in the management of depression in primary care BPAC, 2017
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 18 Feb 2018