About Lithium Antipsychotic, Lithium compounds , Anti manic, Mood stabilizer. Mechanism of Action of Lithium The exact mechanism of action of Lithium is not known. Proposed mechanism is 1. Lithium inhibits the formation of Inositol from Inositol phosphate. Inositol is the precursor for the synthesis of Phosphatidyl Inositol biphosphate (PIP2) which is used for the synthesis of Phospholipase C. Inhibition of Phospholipase C synthesis results in decrease brain Inositol triphosphate (IP3) and Diacyl glycerol (DAG) concentration and reduces the sensitivity of some neurons to the action of various neurotransmitters. 2. Lithium also inhibits second messenger system involving Adenyl cyclase. It alters sodium transport in nerve and muscle cells and increases the interneuronal metabolism of catecholamine and serotonin. 3. Modification of inhibitory neurotransmitter GABA concentrations in the brain 4. Decrease the function of brain protein kinase and alter the release of neurotransmit