NZ Formulary

Amitriptyline

a-mee-trip-ti-leen

What does it do?

Amitriptyline is used to treat and prevent depression, and may also be used for other conditions including some types of pain.

How should you take it?

Take amitriptyline regularly as directed with a glass of water, usually at night time.

What if you forget a dose?

Take the missed dose as soon as possible. If it is close to the time for your next dose, skip the missed dose and carry on as normal. Do not take two doses at the same time.

Can you take other medicines?

Some medicines available without a prescription may react with amitriptyline including:

  • some antihistamines (may be in anti-allergy, anti-nausea and cough/cold medicines)
  • cold and flu medicines containing dextromethorphan (e.g. Robitussin Dry Cough Forte®)
  • anti-sickness medicines (e.g. Sea-legs®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products (e.g. St John's wort) or recreational drugs (e.g. ecstasy).

What side effects might you notice?

Side EffectsRecommended action

Suicidal thoughts

Fast or irregular heartbeat, fainting

Muscle twitching or shaking you can’t control, confusion, heavy sweating, fever

Tell your doctor immediately

Anxiety, restlessness

Tell your doctor

Drowsiness, dizziness, headache, trouble sleeping

Dry mouth, changes in taste or vision, trouble peeing

Constipation, weight gain

More sensitive to sunlight (sunburn or rash)

Changes in sexual function

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have liver, heart, thyroid or prostate problems, or if you have trouble peeing.
  • Tell your doctor if you have glaucoma, bipolar disorder, or if you have ever had a seizure.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Your doctor may do a heart test (ECG) before you start and while you are taking amitriptyline.
  • Amitriptyline can impair your ability to do tasks such as driving or using machines. Alcohol makes this worse. Discuss your risk with your health professional. (search NZTA - Are you safe to drive?)
  • Protect yourself from too much sunlight while being treated with amitriptyline. Always cover up and apply a thick layer of broad spectrum sunscreen (at least SPF 30) when outside. Do not use sunbeds.
  • It may take a few weeks for amitriptyline to start working.
  • If your depression continues to get worse, see your doctor.
  • Do not stop taking amitriptyline without talking to your doctor first.