14.6 : Mania and Antimanic Drugs: Overview

Mania, a psychological condition characterized by elevated mood, increased energy, and reduced sleep need, is part of the bipolar disorder cycle. The exact cause of mania isn't entirely known, but it is thought to be a combination of genetic, environmental, and neurological factors. Bipolar disorder involves alternating manic and depressive episodes. Mood stabilizers like lithium, antipsychotics, and anticonvulsants help manage these episodes. Lithium carbonate is particularly effective as a prophylactic medication against manic and depressive episodes. Its mechanism of action involves inhibiting inositol monophosphatase, increasing IP₃ accumulation through the G_q-PLC-IP₃-Ca²⁺ pathway, impacting monoamines, and reducing arachidonic acid turnover. Despite its effectiveness, lithium has adverse effects such as fine hand tremors, dizziness, xerostomia, GI distress, sedation, and weight gain, especially when combined with antipsychotics. Furthermore, as lithium has a very narrow therapeutic index, lithium toxicity can occur at concentrations above 1.5 mEq/L. Hemodialysis is required for acute toxicity when the concentration is 3 mEq/L or higher.

Antipsychotic drugs like clozapine (Clozaril), olanzapine (Zyprexa), and lurasidone (Latuda) are also used to manage refractory and acute mania individually or as adjunctive therapy. Anticonvulsants such as valproic acid compounds (Depakote) help manage acute mania in pediatric bipolar disorder, while lamotrigine (Lamictal) helps in the maintenance treatment and the prevention of depressive episodes. These drugs, too, have their side effects and require careful administration and monitoring.