Lithium

Lithium is used as psychiatric medication mainly for bipolar disorder and for treatment resistant depressive disorders. Lithium is a simple inorganic ion (same group as potassium and sodium). It was used to treat gout in the 19th century however the levels needed to dissolve uric acid in the laboratory would be toxic in the body. Lithium is on the the WHO’s List of Essential Medicines.

‘Lithium’ comes from the Greek, ‘lithos’ that means ‘stone’ as it is a trace element found in most rocks.

Available as slow-release tablets (lithium carbonate) and liquid form (lithium citrate).

Indications:
Mood stabiliser in bipolar affective disorders and for long term prophylaxis.
For depressive disorders that do not improve following the use of antidepressants.

Mechanism:
Unclear – possibly involves modulation of secondary messenger pathways of cAMP and IP3

Pharmokinetics: Metabolism in kidney; elimination half-life is ~24 hours; >95% excreted by kidney

Toxicity:
Low therapeutic index, so high risk of toxicity (monitoring of serum levels is important) – symptoms include nausea & vomiting; diarrhoea; confusion; drowsiness; psychoses; seizures; coma.
Lithium is teratogenic, especially during the first trimester of pregnancy.

Adverse effects:
A feeling of ‘being sick’; nausea & vomiting; increased urination; tremor, headache, impaired memory, lethargy, fatigue, nausea, anorexia, diarrhoea; dry mouth; metallic taste in the mouth; hyperreflexia.

Long term there can be affects on the kidney and thyroid function, so monitoring is important.

Brand names: Eskalith, Lithobid, Quilonum SR, Priadel, Camcolit, Liskonium, Li-Liquid (and many others)
Chemical formula: Li+

Page last updated: Jun 30, 2022 @ 6:06 am

 
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