‘Safety First: Five-Year Report of the National Confidential Inquiry into Suicide and Homicide by People with Mental Illness’ recommends that patients at risk of suicide, including all patients with a recent history of self-harm, who are treated with psychotropic drugs should receive modern, less toxic drugs and/or supplies lasting no more than 2 weeks.

NOTES ON LITHIUM:

1. Brands of lithium products are not bioequivalent and they must always be prescribed by brand name. If a brand is changed the same precautions should be taken as if starting therapy. Priadel is the only brand used by RCHT and CPT.
2. Lithium toxicity can result from dehydration, reduced sodium eg diuretics, reduced renal excretion or excessive dose. Signs include anorexia, diarrhoea and vomiting. CNS effects include blurred vision, drowsiness, giddiness, ataxia, coarse tremor, and muscle twitching.
3. Nephrotoxicity. Up to one third of patients may develop polydipsia and polyuria which is usually reversible on withdrawal. Long term treatment may result in permanent changes and renal impairment. The excretion of lithium is dependent on renal function. Anything which affects sodium levels eg diuretics, or renal function eg NSAIDs, will affect blood levels of lithium which may become toxic.
4. Lithium interacts with several drugs. Consult reference books, specialists or Medicines Information Department at RCHT for guidance.
5. Monitoring. Baseline measurement of renal, cardiac and thyroid function should be undertaken. Plasma lithium levels should be monitored 5 - 7 days after starting, then weekly until stabilized in the therapeutic range, then monthly, then if stable every 3 months. The sample should be taken 12 hours post-dose. Renal and thyroid function should be checked every 6 months. Check levels after a dose change or if starting or stopping another drug which might interact with lithium. Usual target range as a mood stabilizer is 0.6 - 0.8 mmol / L for adults, but lower in elderly eg 0.4 mmol / L.
6. Stopping lithium abruptly can cause relapse; if planning to stop lithium therapy reduce doses gradually over at least 1 month unless medical emergency.