lithium
n. an element of the alkali metal group whose salts are used in psychopharmacotherapy as mood stabilizers. Lithium salts were first used for the treatment of mania in the 1940s, but widespread use was limited by their toxicity. However, after further investigations into their role in treating bipolar depression and better appreciation of the appropriate dosage, lithium salts entered broader clinical practice in the 1970s. Although its primary indication is in managing bipolar disorder, lithium has some efficacy in managing acute manic phases and in reducing relapse. Its mechanism of action remains unclear; it may work via inhibition of the recycling of inositol from the inositol phosphates, which are second messengers in cellular signaling. Toxic doses are no more than two to three times the therapeutic dose, and serum monitoring is required. Symptoms of acute toxicity include tremors, diarrhea, vomiting, and incoordination; at higher doses,
disturbances of heart rhythm and neurological function leading to coma and death may occur. Long-term lithium use can cause thyroid and renal dysfunction in a small percentage of patients. Lithium has been associated with fetal cardiac malformation (Ebstein’s anomaly), and its use during pregnancy is not recommended. U.S. trade names (among others): Eskalith; Lithobid.