Mechanism of action of lithium

The mechanism of action of lithium is not well defined. The drug inhibits several enzymes involved in the recycling of neuronal membrane phosphoinositides. This action may result in depletion of the second messenger source, phosphatidylinositol bisphosphate (PIP2), which, in turn, would decrease generation of (IP3) and (DAG). These second messengers are important in amine neurotransmission, including that mediated by central adrenoceptors and muscarinic receptors.