Clinical use
Lithium is a mood stabiliser, licensed for use in the prophylaxis and treatment of bipolar disorder, mania, recurrent major depressive disorder and aggressive or self-harming behaviour. It may be used outside of the product licence for indications such as prophylaxis of cluster headaches and migraines.
Lithium has specific prescribing and monitoring requirements.
All HCPs who interact with individuals on lithium must know the clinical considerations for safe use and the importance of managing the associated risks.
NICE have produced guidance on the use of lithium in bipolar disorder, depression and antenatal and postnatal mental health.
Prescribing information can be found in the BNF, under monographs for lithium carbonate and lithium citrate, and in the NICE Clinical Knowledge Summary on lithium.
Patient harm
The potential harms associated with lithium use can significantly impact people’s health and experiences of using healthcare. Harms have been reported at all stages of the patient journey and in all care settings.
Lithium is a high-risk medicine with a narrow therapeutic index and harm can occur due to:
- lack of adequate monitoring
- failure to recognise and respond appropriately to adverse effects or out of range levels
- prescribing interacting medicines
- missed doses
- poor communication at transfers and interfaces of care
- inappropriate referral to non-urgent review pathways when urgent treatment is required
Key risks and mitigation strategies
Awareness of lithium products and formulations
Lithium is available as immediate-release tablets or slow-release tablets (lithium carbonate). Brand names for the tablets include Priadel®, Camcolit® and Liskonum®. It also comes as a liquid (lithium citrate). Brands of lithium liquid available in the UK are Priadel® and Li-liquid®. Other salts may be available from other countries.
Dose equivalence and conversion
Most lithium formulations and salts are not bioequivalent and therefore not interchangeable. Prescribers must prescribe lithium by brand name and form, as discussed in Example medicines to prescribe by brand name in primary care (SPS page). Changing the preparation or formulation requires the dose and frequency to be reviewed and close monitoring of lithium levels. Further information can be found in Specific medicine switches for solid dose and liquid formulations (SPS page).
Interactions
Lithium has clinically significant interactions that prescribers must be aware of. See the BNF for further information. Understanding drug interactions (SPS page) helps to support decision making.
Monitoring
Lithium has a narrow therapeutic index and therefore monitoring is required to ensure levels do not become toxic or subtherapeutic. Patients should have regular physical health monitoring.
The lithium target range is individual to each patient and may vary during their treatment. The range should be communicated to all those involved in the patient’s care.
The SPS Medicines Monitoring Tool (SPS page) has more information about lithium monitoring. Safe management of therapeutic drug monitoring (SPS page) contains information to support the safe management of drugs requiring therapeutic drug monitoring.
Subtherapeutic level
If the lithium level is below the target range, the dose should be reviewed in consultation with the patient. Remember to always treat the patient not the level. Missed doses of lithium can cause subtherapeutic levels which may lead to a relapse of the underlying condition. This may lead to serious patient harm.
Toxicity
Lithium toxicity can lead to significant patient harm and can be fatal. Toxicity can be prevented by regular blood tests to check lithium levels and taking timely appropriate action in response to results.
Neurotoxicity can also occur at plasma levels within the target range so all HCPs involved in the patient’s care must be aware of the signs and symptoms.
Patients more susceptible to neurotoxicity require closer monitoring such as those who are frail.
The SPS lithium monitoring tool (SPS page) has further information, including signs of toxicity.
Lithium monitoring resources
The NHS England lithium resources include an alert card, information book and monitoring book and should be given to all patients at the point of prescribing. These should be used to support patients in their understanding of lithium.
Ordering information is available in Accessing resources for patients on high risk medicines (SPS page). HCPs involved in prescribing, dispensing or monitoring lithium should:
- check blood tests are being monitored regularly
- encourage ongoing recording in the patient monitoring book or a digital alternative
Pregnancy and breastfeeding
Patients prescribed lithium who are planning or become pregnant should be referred to their prescriber or local perinatal mental health service for urgent review. The series of articles about safe use of medicines in pregnancy (SPS page) provides general information about key risks and principles to ensure safe, informed decisions. NICE have guidance on lithium use in antenatal and postnatal mental health.
Standardised approach
It is important to standardise practice whilst ensuring a personalised approach. Clear policies, guidelines and standard operating procedures help to outline good practice and may reduce lithium-related harm.
Defining responsibilities
Harm can occur when responsibilities for lithium management are not defined, including across organisations and healthcare settings. Roles and responsibilities must be clear and understood across the system.
Ensure there are defined responsibilities for:
- Initiating and prescribing lithium
- Administration (where applicable)
- Supplying the lithium resources (alert card, information book and monitoring book)
- Counselling, including adverse effects and when to seek help
- Checking interactions
- Organising regular blood tests
- Checking blood test results
- Acting on blood test results
- Checking and acting on regular physical health checks other than blood tests for example, weight
- Communicating relevant information such as blood results and dose changes to the patient and others involved in their care
- Compiling and managing a lithium patient register
- Informing the specialist mental health team about any transfers of care
You should make sure there are clear processes in place for the above, including arrangements for out‑of‑hours care. It is important to include details such as how to contact specialist mental health teams and how to access information about patients’ regular medicines.
Shared care
The national shared care template for lithium has expired but may contain some useful information that can be transferred for use via an approved local mechanism.
Using digital systems
Digital systems can introduce risks but can also help to mitigate them. Use digital solutions such as the Discharge Medicines Service and electronic prescribing systems where possible.
Consider how blood results are accessed by other services such as primary care or specialists and ensure they are available to everyone who needs them.
Ensure lithium is included in all relevant electronic lists on the patient medical record. For example, if lithium is prescribed and supplied outside of primary care ensure it is added as a hospital only medicine to the GP clinical system. NHS England has guidance on recording medicines prescribed elsewhere into the GP practice record. This helps to ensure the relevant people are aware of the lithium prescription and it is included in interaction and clinical decision support software. Some systems only retain additions temporarily, so robust processes are required to ensure records remain accurate and up to date.
Uncollected prescriptions can be a sign of unaddressed problems, such as non-adherence or poor communication. Review digital systems for potential functionality, such as highlighting uncollected prescriptions to identify potential patients for medication review.
Patient education
Counselling points for lithium include the importance of adherence, adverse effects, potential interactions and dietary considerations such as salt intake. More information can be found on the NHS website and in the lithium therapy information book. SPS has guidance on advising on missed or delayed doses of medicines (SPS page).
Dehydration can lead to acute or chronic toxicity and can be caused by illness (such as diarrhoea or vomiting), heat, alcohol, exercise, and some medicines, for example diuretics. This should also be considered when patients are fasting. The British Islamic Medical Association has further advice around fasting during Ramadan.
Ensure patients have all the lithium patient resources, understand the content and how to use them. The NHS app can help with access to blood results.
Specialist advice
Close working relationships with local mental health services can support timely access to specialist support. Provision of ‘in-reach’ specialist mental health pharmacy services from local mental health trusts to secondary care enables a point of contact for advice and queries.
Some acute hospitals will have a psychiatric liaison team who can offer support and advice.
Ensure all healthcare staff have an awareness of the referral process for this.
Contact details
Ensure contact details for local mental health trusts, including the out of hours service, are on the ICB webpage and the local intranet. Raise awareness of the availability of this information through your organisation’s usual communication channels, including to local NHS 111 and ambulance services.