- Lithium, oral, 250 mg 12 hourly.
- Usual dose range: 200–500 mg/dose 12 hourly.
- May be given as a single total daily dose at night to improve adherence and to protect renal function.
- Measure serum concentrations at steady state (i.e. after 5 days) at about 12 hours after the last dose.
- Lithium has a narrow therapeutic window. The therapeutic range is 0.4–0.8 mmol/L for maintenance therapy, and 0.8–1.0 mmol/L in mania.
- If levels are sub-therapeutic and the patient is adherent increase the daily dose by 250 mg and repeat trough plasma levels after 5 days.
- Maintain therapeutic blood levels of lithium for as long as the patient is on lithium. Monitor lithium levels and renal function at least monthly for the first 3 months of therapy.
- Monitor lithium levels 6 monthly once stable levels have been achieved, together with serum creatinine, sodium and potassium.
- Check TSH (for lithium-induced hypothyroidism) and serum calcium (for lithium-induced hyperparathyroidism) before starting treatment and annually thereafter.
- Beware of combining lithium with ACE-inhibitors, NSAIDs and thiazide diuretics, as they all potentiate the risk for lithium toxicity.
Pregnancy - Lithium has been associated with congenital abnormalities in the newborn with first trimester exposure. Risk-benefit assessment required for indication of maternal use during pregnancy.