The FDA has approved Lybalvi (Alkermes), a fixed-dose combination of the second-generation antipsychotic olanzapine (Zyprexa, and generics) and samidorphan, a new opioid antagonist, for treatment of adults with schizophrenia or with manic or mixed episodes of bipolar I disorder. The addition of samidorphan is intended to mitigate the weight gain that occurs with olanzapine. This is the first FDA approval for samidorphan.

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 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).

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 oral second-generation antipsychotic drug lumateperone (Caplyta – Intra-Cellular Therapies), which was approved by the FDA in 2020 for treatment of schizophrenia, is now approved for use as monotherapy or as an adjunct to lithium or valproate for treatment of depressive episodes associated with bipolar I or II disorder in adults.

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.

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).

The FDA has approved a sublingual film formulation of the alpha-2 adrenergic receptor agonist dexmedetomidine (Igalmi — BioXcel Therapeutics) for acute treatment of agitation associated with schizophrenia or bipolar I or II disorder in adults. It is the first alpha-2 agonist and the only sublingual film to be approved for this indication. Dexmedetomidine has been available for many years in an injectable formulation (Precedex) for sedation in the intensive care unit and to facilitate procedures such as mechanical ventilation.

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.

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.