Lithium carbonate

Commonly called lithium

Lithium carbonate is used to treat some types of mental illness such as bipolar disorder. Find out how to take it safely and possible side effects. Lithium carbonate is also called Priadel.

Type of medicine Also called
  • Mood stabiliser
  • Medicine to treat bipolar disorder
  • Priadel®
  • Lithium carbonate®

What is lithium?

Lithium is used to treat bipolar disorder (previously called manic depression). It does not cure this condition, but is used to help ease the symptoms and help you on your recovery path. 

Lithium prevents mood swings, reduces how often manic episodes occur and decreases the symptoms of mania, such as extremely elated mood, irritability, anxiousness, rapid or loud speech, and aggressive, hostile behaviours. Read more about bipolar disorder

In New Zealand lithium is available as capsules and tablets. The amount of lithium released from products made by different manufacturers varies, so it's important to always take the same brand of lithium.

  • 250 mg capsules called Lithium Carbonate (Douglas)®
  • 400 mg modified release tablet called Priadel®. This type of tablet releases the medicine slowly into your bloodstream. 

Note: Lithicarb FC 250 mg and 400 mg tablets are no longer available in New Zealand. 


  • The dose of lithium varies from person to person, depending on your response to the medicine and your lithium blood level (see below). 
  • Your doctor will start you on a low dose and increase it slowly as your body gets used to the medicine.
  • The usual dose is 400 to 1200 mg daily, taken as a single dose or in 2 divided doses.
  • Always take your lithium exactly as your doctor has told you.
  • The pharmacy label on your medicine will tell you how much lithium to take, how often to take it and any special instructions.

How to take lithium

  • Timing: Lithium is usually taken once a day in the morning or two times a day, in the morning and evening. It is best to take your lithium dose at the same times each day. It is best to take each dose with food to reduce nausea (feeling sick) and stomach upset.
  • Swallow lithium tablets and capsules with a full glass of water. Do not crush, chew or take the tablets with hot liquids. 
  • Limit drinking alcohol while you are taking lithium. Alcohol may increase your chance of side effects such as drowsiness. Alcohol can also cause dehydration which in turn can affect your lithium levels. 
  • Missed dose: If you forget 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 lithium every day. It usually takes a few weeks to start working and it can take several months before you feel the full benefits. Do not stop taking lithium suddenly as your symptoms may return if you stop taking it too early. Talk to your doctor or nurse before stopping because if you do need to stop taking lithium it should be reduced slowly.

Precautions before taking lithium

  • Do you have problems with your liver or kidneys?
  • Do you have problems with your heart, such as atrial fibrillation?
  • Do you have problems with your thyroid function?
  • Are you breastfeeding?

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

Are you pregnant or planning a pregnancy?

Tell your doctor if you are or become pregnant, or are trying for a baby. Lithium can increase the risk of a baby having a birth defect when taken during pregnancy. Your doctor will talk with you about your options. You may need to change treatment. Do not stop taking lithium without talking to your doctor. Read more about taking lithium during pregnancy.

Monitoring and tests

Lithium levels

You will need to have regular blood tests to make sure that your lithium dose is adjusted to suit you. This is because the amount of lithium in your bloodstream has to be just right – too little and it will not work well, too much and it could be harmful.

These blood tests are referred to as ‘a lithium level’, a serum lithium level or a plasma lithium level. They are needed weekly in the early stages of your treatment and if your dose is changed, but they are needed less often (3 monthly) once your lithium level is stable. 

  • The usual target lithium level is 0.6–0.8 mmol/L. It can be lower for maintenance therapy and older people.
  • Higher concentrations of 0.8–1 mmol/L are recommended in some people with more severe symptoms.
  • A lithium level of more than 1.2 mmol/L is usually considered high and requires medical attention, as it can be harmful.

Factors that can change your lithium levels

  • Dehydration  you should drink plenty of water each day, but try to drink about the same amount every day, as any large changes in how much you drink may affect your lithium levels.
  • Changes to your diet including the amount of salt in your diet can affect your levels. If you plan to make any major changes to what you eat (such as going on a diet), talk about this with your doctor first.
  • Being unwell – if you get an infection or an illness that causes you to sweat a lot, or be sick (vomit) or have diarrhoea (runny poos), it could affect your lithium levels. If this happens, talk to with your doctor for advice about what you should do.
  • Changing the brand of lithium you are taking – the amount of lithium released from products made by different manufacturers varies, so it is important that you always take the same brand of lithium.
  • Taking other medicines, including herbal products. Many medicines can affect your lithium levels. Always check with your pharmacist or doctor before you take any other medicines. This is important if you are buying painkillers that contain a non-steroidal anti-inflammatory medicine (NSAID), such as ibuprofen. 
  • Timing of the blood test to check your lithium level – it is important that blood tests for lithium levels are taken at least 12 hours after you take your last dose of lithium. If blood is taken before this time, the lithium level would not have settled down in your blood since the last dose.

Signs that your lithium levels are too high

Having high levels of lithium in your blood can be harmful. This is best avoided by taking the right dose, keeping a steady fluid and salt intake and having regular blood tests. It is also helpful for you and your family to know the signs of high lithium levels (listed below) so that you can respond quickly and seek immediate medical attention.

 See a doctor urgently if you have any of the following signs:
  • severe tremor (shaking hands)
  • stomach ache along with nausea (feeling sick) and diarrhoea (runny poos)
  • muscle weakness
  • being unsteady on your feet 
  • feeling unusually sleepy
  • muscle twitches
  • slurring of words, so that it is difficult for others to understand what you are saying
  • blurred vision
  • confusion

A small number of people may not have any symptoms of toxicity when the level of lithium in their blood is too high.

Other tests

Lithium may cause changes in your weight, the way your thyroid gland works and your heart and kidney function. To keep an eye out for these effects, your doctor will monitor your health.

Before you start lithium and while you are taking it, you will have your weight measured and may be sent for tests to monitor your kidney and thyroid function and an ECG test to assess your heart rate.

What are the side effects of lithium carbonate?

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

Side effects What should I do?
  • Nausea (feeling sick) or vomiting (being sick)
  • Take lithium with or after food.
  • Fine tremor
  • This usually occurs when you first start taking lithium but goes away with time.
  • If it doesn’t go away, talk to your doctor.
  • Difficulty concentrating
  • Be careful when driving or operating machinery until you know how this medicine affects you.  
  • Weight gain 
  • A diet full of vegetables and fibre may help prevent weight gain.
  • Limit sugary or fatty foods.
  • Speak with your doctor if your weight becomes troublesome.


  • Lithium interacts with a few medicines and herbal supplements, so check with your doctor or pharmacist before starting lithium or before starting any new medicines.
  • Also, check with a pharmacist before taking over-the-counter medicines such as cold and flu medicines and NSAIDs such as ibuprofen.

Learn more

The following links have more information on lithium. Be aware that websites from other countries may have information that differs from New Zealand recommendations. 

Lithium carbonate Consumer information, Medsafe, NZ
Priadel Consumer information, Medsafe, NZ
Lithium tablets Patient Info, UK, 2016 
Lithium and other mood stabilisers Mind, UK, 2015


  1. Lithium carbonate NZ Formulary
  2. Bipolar disorder: identifying and supporting patients in primary care BPAC, NZ, 2014
  3. Lithium and pregnancy Medsafe, NZ, 2019
  4. Lithium therapy National Patient Safety, NHS, 2009
Credits: Health Navigator Editorial Team. Reviewed By: Angela Lambie, Pharmacist Last reviewed: 26 Feb 2018