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What does it do?

Lithium is used to treat some mental health problems such as bipolar disorder. It is also sometimes used for other conditions.

Before you start

  • Tell your doctor if you have heart, kidney or thyroid problems, psoriasis, if you have ever had a seizure or are having electroconvulsive therapy (ECT).
  • 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 lithium.

How should you take it?

Take lithium regularly as directed with food and a glass of water.
The controlled release (CR) tablets can be halved, but do not crush or chew them.

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 lithium including:

  • anti-inflammatories, such as diclofenac (e.g. Voltaren®) or ibuprofen (e.g. Nurofen®). These can also be found in some cold and flu medicines (e.g. Nurofen Cold and Flu®).
  • cold and flu medicines containing dextromethorphan (e.g. Robitussin Dry Cough Forte®)
  • some migraine medicines, such as sumatriptan (e.g. Sumagran Active®)

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

Symptoms of too much lithium, including: severe tremor or twitching, unsteadiness, dizziness, drowsiness, muscle weakness, slurred speech, confusion, blurred vision, diarrhoea, vomiting

Stop taking and see your doctor immediately

Fast or irregular heartbeat, fainting

Headache, changes in vision, pounding in one or both ears (may be intracranial hypertension)

Tell your doctor immediately

Tremor, numbness or tingling of the fingers or toes

Peeing more often, feeling thirsty

Tell your doctor


Changes in taste, dry mouth, change of appetite, weight gain

Stomach upset

Swollen feet or legs

Hair loss or thinning, acne

Tell your doctor if troublesome

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

Other information:

  • You will need blood tests to make sure you are taking the correct dose of lithium, especially if you start or stop other medicines or have changes in your health.
  • The amount of salt in your diet can change the effect of lithium. Talk to your doctor before you change the amount of salt you eat.
  • It is important not to become dehydrated while taking lithium.
  • Lithium 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?)
  • Do not stop taking lithium without talking to your doctor first.

This leaflet contains important, but not all, information about this medicine.

Prepared by the MyMedicines Committee at Christchurch Hospital, Te Whatu Ora - Waitaha, New Zealand. March 2023

For more general information about this sheet and its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at Te Whatu Ora – Waitaha. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed