From the FDA Drug Label
DOSAGE AND ADMINISTRATION Acute Mania: Optimal patient response to lithium carbonate usually can be established and maintained with 600 mg t.i.d.. Dosage must be individualized according to serum levels and clinical response. The maximum recommended dose of lithium is not explicitly stated in the drug label.
- Key points:
- The dose of 600 mg t.i.d. is mentioned for acute mania.
- Dosage must be individualized. 1
From the Research
The maximum recommended dose of lithium should not exceed 1300 mg per day for adults, with serum levels maintained between 0.6-0.8 mEq/L for maintenance therapy, as higher doses and levels are associated with increased risk of thyroid dysfunction and chronic kidney disease. Lithium dosing is highly individualized and requires regular blood monitoring, as the therapeutic window is narrow and toxicity can occur at levels above 1.5 mEq/L 2. Patients should have their lithium levels checked every 3-6 months once stabilized, and more frequently when initiating treatment or adjusting doses. Factors affecting lithium levels include kidney function, age, pregnancy, sodium intake, and interactions with medications like NSAIDs and diuretics.
Some key points to consider when prescribing lithium include:
- The usual maintenance daily dose is 25-35 mmol (lithium carbonate 925-1300 mg) for patients aged <40 years; 20-25 mmol (740-925 mg) for those aged 40-60 years; and 15-20 mmol (550-740 mg) for patients aged >60 years 3.
- Lithium serum levels greater than 0.5028 mEq/L, greater than 0.5034 mEq/L, and greater than 0.5865 mEq/L represent thresholds associated with hypothyroidism, hyperthyroidism, and CKD3+, respectively 2.
- Valproate, olanzapine, quetiapine, and risperidone generally exhibit reduced likelihood of thyroid dysfunction and CKD3+ compared with lithium, without any difference in advanced CKD 2.
- A single daily dose of lithium can be a viable method to reduce the side effects of lithium, which may lead to better patient compliance 4.
Signs of lithium toxicity include tremor, confusion, vomiting, diarrhea, and ataxia. Lithium works by modulating neurotransmitter systems and stabilizing neuronal membranes, making it effective for bipolar disorder, but its narrow therapeutic index necessitates careful monitoring and individualized dosing 3, 2.