Lithium
Background
- Primarily used for uni / bipolar depression
- Narrow therapeutic range (0.4 - 1.0 mmol/). Toxicity at 2.0 mmol/l
- Acute toxicity
- Thirst, polyuria, tremor, dysarthria, ataxia, arrhythmia & coma
- Chronic toxicity
- Acne, hypothyroidism, alopecia & psoriasis
Toxicity
- Readily absorbed in GI tract over 4 - 6 hours post overdose.
- Widely distributed
- Not protein bound - circulates as simple cation
- Renal excretion
- Elimination t1/2 usually 24 hours but dependant upon renal function
- Acute toxicity usually occurs on background of chronic with altered metabolism eg dehydration
Management
Admit all with symptoms of toxicity or levels > 2mmol/l
Supportive management - A, B, C with correction fluid / electrolyte imbalance
Avoid charcoal
GI Tract decontamination unhelpful
Whole bowel irrigation MAY be useful (no evidence either way) if sustained release preparation ingested
Avoid forced diuresis
Haemodialysis (repeated to treat rebound post treatment levels) very effective
Haemodialysis indications (severe / life threatening overdose)
- Progressive clinical deterioration
- Life threatening arrhythmias
- Coma, seizures, respiratory failure
- Rising serum lithium concentration
- Impaired renal fxn
- Serum Li conc > 4 mmol/l in acute on chronic toxicity
- Serum Li conc > 8 mmol/l in acute toxicity
Links
- TOXBASE (Check resuscitation room PC for login details) (Toxbase email)
- Phone at The National Poisons Information Service
- The BNF is also available on line
Content by - Dr Íomhar O' Sullivan. 12/01/2001. Reviewed by Dr ÍOS 08/02/2003, 10/04/2004, 18/05/2005, 13/05/2007. next review 13/05/2008