Lithium Toxicity

Excerpt

The drug of choice for recurrent bipolar illness management remains to be lithium. Lithium, a monovalent cation similar to sodium with an unknown mechanism, was first approved by the U.S. Food and Drug Administration (FDA) as a mood-stabilizing medication for the treatment of mania in the 1970s. Lithium is a very powerful, antimanic medication with a narrow therapeutic index.

PharmacodynamicsLithium's physiologic role is unknown, and its mechanism is not well understood; however, some proposed mechanisms include:

1. Producing brain inositol depletion, leading to reduced responsiveness to alpha-adrenergic stimulation .

2. Reducing neuronal responsiveness to neurotransmitters due to inhibitory effects on adenylate cyclase and G proteins vital for ion channel opening.

3. Stimulating serotonin release from the hippocampus .

4. Being a cation, acting similar to potassium and sodium, thus affecting ion transport and cell membrane potential .