Aripiprazole

The pharmacology, pharmacokinetics, clinical efficacy, adverse effects, interactions, and dosage and administration of aripiprazole are discussed. Aripiprazole is a third-generation antipsychotic agent indicated for use in the treatment of schizophrenia. Unlike other anti-psychotic agents, aripiprazole demonstrates mixed D-2, and serotonin (5-HT1A) receptor agonist-antagonist activity that is hypothesized to improve schizophrenia's positive and negative symptoms; the drug has been referred to as a dopamine-serotonin stabilizer. Aripiprazole is well absorbed, with peak plasma concentrations occurring within three to five hours after administration. The oral availability is 87%. The mean elimination half-life is about 75 hours for aripiprazole and 94 hours for its active metabolite. In controlled, randomized, multi-center trials, aripiprazole has demonstrated efficacy in the treatment of schizophrenia comparable to that of haloperidol and superior to placebo. In a single clinical trial, aripiprazole was superior to placebo in the treatment of acute mania. The most frequent adverse effects are headache, anxiety, insomnia; nausea, vomiting, and lightheadedness. Because aripiprazole is a substrate: of both cytochrome P-450 isoenzymes 3A4 and 2D6, there is a potential for other drugs to affect its metabolism. The recommended starting dosage is 10 or 15 mg daily, preferably administered with meals. Aripiprazole offers an alternative to second-generation antipsychotic agents in the treatment of schizophrenia.