Clinical Significance

Lithium is used in the treatment of manic depressive psychosis. It acts on the neurotransmitters and produces a sedative effect on the CNS. Because lithium has a narrow therapeutic range, it should be monitored closely for toxicity. Elevated levels can cause toxicity. Early symptoms of toxicity include apathy, sluggishness, drowsiness, lethargy, speech difficulties, tremor, muscle weakness, and ataxia.

Long-term lithium therapy has been reported to cause hyperparathyroidism in some individuals, with resulting hypercalcemia.