High risk medicines: lithium

Lithium is used as a mood stabiliser.

Lithium is sometimes prescribed in the management and treatment of: 

• mania
• hypomania
• recurrent depression
• bipolar disorder.

Always prescribe lithium by brand name so that the person receives the same medicine each time. This is because different brands may be absorbed differently. 

Lithium salts are available as the following brands in the UK: 

• Camcolit^®
• Liskonum^®
• Priadel^®
• Li-Liquid^®.

Prescribing

A specialist in secondary care will usually start a prescription for lithium. This is because doses need to be changed based on serum lithium levels and clinical response.

A hospital and GP may share responsibility for prescribing lithium. So, when you complete a medicines reconciliation, make sure you have a complete medicines history. For example, medicines prescribed by a hospital or a community mental health team may not appear on the GP summary.

If a person you care for is discharged from hospital, you must check if there have been any changes. Are they taking the same brand or formulation (for example, tablets changed to liquid)? 

You should:

• communicate with the prescriber and supplying pharmacy
• request a new prescription from the person’s GP if needed
• discard any medicine that is no longer prescribed.

Monitoring

Lithium levels are usually monitored every 3 to 6 months. This is sometimes more frequent in people with increased health risks.

People should have blood tests every 6 months to check:

• thyroid hormone levels
• kidney function
• cardiac function.

People’s body mass index or weight should be monitored and recorded.

You also need to take regular blood tests so that the correct dose is prescribed. If the prescribed dose is too low, the medicine will not be effective. If the dose is too high, it could be harmful due to lithium toxicity. Very rarely, a high dose can be fatal.

You should:

• record in the care plan who is responsible for monitoring
• support people to attend appointments for monitoring.

Administering

Lithium is usually taken at night. This is because a person needs a blood test at least 12 hours after they take their last dose. A blood sample is taken the next day.

Most lithium tablets are 'modified release' and people should not crush or chew them.

Safety guidance

Specialist Pharmacy Service has issued guidance to highlight the importance of lithium compliance and monitoring. People may have a digital record or paper booklet with supporting information.

These explain important information about:

• the medicine
• how to take it
• how to recognise side effects
• how to keep track of ongoing blood monitoring.

Be aware of the signs of lithium toxicity. Contact the GP if any symptoms present. Symptoms include:

• blurred vision
• vomiting
• diarrhoea
• muscle weakness
• drowsiness
• feeling shaky
• lack of co-ordination.

Always maintain adequate fluid intake. Dehydration can cause lithium toxicity.

Lithium interacts with many other medicines. Check with an appropriate healthcare professional if people need over-the-counter medicines.