The oral second-generation antipsychotic drug iloperidone (Fanapt – Vanda) has been approved by the FDA for acute treatment of manic or mixed episodes associated with bipolar I disorder in adults. First approved in 2009 for treatment of schizophrenia, iloperidone is the eighth second-generation antipsychotic to be approved for acute treatment of manic or mixed episodes of bipolar I disorder (see Table 1).

Paliperidone (Invega - Janssen) has been approved by the FDA in an extended-release formulation for treatment of schizophrenia. It is the primary active metabolite of the second-generation antipsychotic risperidone (Risperdal - Janssen), which is scheduled to lose its patent exclusivity in December 2007.

The FDA has approved the oral, once-daily, second-generation antipsychotic brexpiprazole (Rexulti – Otsuka/Lundbeck) for treatment of schizophrenia and as an adjunct to antidepressants for treatment of major depressive disorder (MDD). Aripiprazole (Abilify), a structurally similar second-generation antipsychotic also comarketed by Otsuka (with BMS), recently became available generically.

The FDA has reported that 5106 elderly patients with dementia treated with atypical (second generation) antipsychotics in 17 randomized controlled trials had a higher mortality rate (4.5% vs. 2.6%) than those receiving placebo. Most of the deaths were due to cardiovascular and infectious causes (such as pneumonia). The drugs used in the trials were aripiprazole (Abilify), olanzapine (Zyprexa), quetiapine (Seroquel), and risperidone (Risperdal). As the increase in mortality was considered a class effect, the FDA advisory also included ziprasidone (Geodon), clozapine (Clozaril) and the...

The FDA has approved lumateperone (Caplyta — Intracellular Therapies), an oral second-generation antipsychotic, for once-daily treatment of schizophrenia in adults. It is the 13th second-generation antipsychotic drug to be approved by the FDA for this indication.

An extended-release injectable formulation of the second-generation antipsychotic aripiprazole (Abilify) has been approved by the FDA (Abilify Maintena – Otsuka/Lundbeck) for once-monthly treatment of schizophrenia. It is the fourth second-generation antipsychotic to become available in a long-acting parenteral formulation. Long-acting parenteral antipsychotics, given at intervals of 2-4 weeks, are generally used for patients with a history of relapse due to poor adherence to oral maintenance therapy.

The FDA has approved cariprazine (Vraylar – Actavis), an oral, once-daily, second-generation antipsychotic, for treatment of schizophrenia and for acute treatment of manic or mixed episodes associated with bipolar I disorder.

An extended-release formulation of carbamazepine, available since 1997 for treatment of epilepsy, has now been approved under a new name, Equetro, for acute mania and mixed episodes of bipolar disorder. Although the drug was effective in some patients for up to 6 months, it has not been approved for maintenance treatment. Carbamazepine has not been shown to be more effective than lithium or valproate, and it can cause serious adverse effects.

Tetrabenazine (Xenazine - Ovation Pharmaceuticals), an old drug first synthesized 50 years ago for treatment of schizophrenia, was recently approved by the FDA for the treatment of chorea associated with Huntington's disease. It has been available in other countries for decades.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.