Three extended-release injectable formulations of second-generation antipsychotic drugs — two of risperidone (Rykindo, Uzedy) and one of aripiprazole (Abilify Asimtufii) — have been approved by the FDA for treatment of schizophrenia in adults. Rykindo and Abilify Asimtufii are also approved for maintenance treatment of bipolar I disorder in adults. Other extended-release injectable formulations of risperidone and aripiprazole have been available in the US for years (see Table 1).

Bipolar disorder is characterized by episodes of mania, hypomania, and depression. Recurrences of manic or (more frequently) depressive symptoms are common. About 15-20% of patients with bipolar disorder die by suicide.

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.

Invega Hafyera (Janssen), a long-acting, extended-release (ER) formulation of the second-generation antipsychotic paliperidone palmitate, has been approved by the FDA for twice-yearly IM treatment of schizophrenia in adults who have been adequately treated with another injectable ER formulation of the drug (Invega Sustenna or Invega Trinza). It is the first drug to become available in the US for twice-yearly treatment of schizophrenia.

The FDA has approved the second-generation antipsychotic drug cariprazine (Vraylar — Abbvie) for adjunctive treatment of major depressive disorder (MDD) in adults. Cariprazine was previously approved for treatment of schizophrenia and bipolar depression, and for acute treatment of manic or mixed episodes associated with bipolar I disorder.

The FDA has approved the oral second-generation antipsychotic drug brexpiprazole (Rexulti – Otsuka/Lundbeck) for once-daily treatment of agitation associated with dementia due to Alzheimer's disease (AD). Brexpiprazole is the first drug to be approved in the US for this indication. It is also approved for treatment of schizophrenia and as an adjunct to antidepressants for treatment of major depressive disorder.

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).

A selective serotonin reuptake inhibitor (SSRI) is generally used for initial treatment of major depressive disorder (MDD). A serotonin-norepinephrine reuptake inhibitor (SNRI), bupropion (Wellbutrin SR, and others), and mirtazapine (Remeron, and others) are reasonable alternatives. Improvement in symptoms can occur within the first two weeks of treatment with these drugs, but a substantial benefit may not be achieved for 4-8 weeks.