Lithium citrate

How it works

Its precise mechanism is uncertain, but lithium is thought to modulate neuronal signal transduction, including effects on second-messenger systems, to stabilise mood.

Prescribing in practice

• Lithium has a narrow therapeutic index, and toxicity can be life-threatening, so serum lithium concentrations must be monitored and patients warned about precipitants such as dehydration, infection and interacting drugs.
• Different lithium preparations vary in bioavailability, so the brand should not be changed without re-checking serum levels.
• Renal, thyroid and cardiac function require assessment before and during treatment, as lithium can affect the kidneys and thyroid.

Monitoring

Monitor serum lithium concentrations regularly, together with renal and thyroid function, and review for signs of toxicity such as tremor, vomiting, diarrhoea and confusion.

Counselling the patient

• Maintain a consistent fluid and salt intake and avoid becoming dehydrated.
• Carry a lithium alert card and attend for blood tests as scheduled.
• Seek urgent advice for coarse tremor, persistent vomiting, diarrhoea or drowsiness.

Evidence & guidelines

Lithium is a long-established, evidence-based mood stabiliser recommended by NICE for bipolar disorder, with the MHRA emphasising the need for routine monitoring.