The FDA has approved Cobenfy (BMS), an oral fixed-dose combination of the muscarinic agonist xanomeline and the peripheral muscarinic antagonist trospium chloride, for treatment of schizophrenia in adults. It is the first antipsychotic drug to be approved in the US for treatment of schizophrenia that does not block dopamine receptors. This is the first approval for xanomeline; trospium has been available for many years for treatment of overactive bladder.

Gabapentin enacarbil (Horizant – GlaxoSmithKline), a new extended-release (ER) tablet formulation of gabapentin, has been approved by the FDA for treatment of moderate-to-severe restless legs syndrome (RLS). The immediate-release (IR) formulation of gabapentin (Neurontin,and others), which is approved for treatment of epilepsy and postherpetic neuralgia, has been used for many years to treat RLS. Another ER tablet formulation of gabapentin (Gralise) has been approved by the FDA for treatment of postherpetic neuralgia.

The FDA has approved Inbrija (Acorda), an orally inhaled dry-powder formulation of levodopa, for intermittent treatment of "off" episodes in patients with Parkinson's disease (PD) being treated with carbidopa/levodopa (Sinemet, and others).

The FDA has approved the monoamine oxidase type B (MAO-B) inhibitor safinamide (Xadago – US Worldmeds) as an adjunct to levodopa/carbidopa for management of "off" episodes in patients with Parkinson’s disease (PD). It is the first reversible MAO-B inhibitor to be approved for this indication. Selegiline (Eldepryl, and others) and rasagiline (Azilect, and generics), two irreversible MAO-B inhibitors, have been used alone and as adjuncts to levodopa/carbidopa for many years. Safinamide is not approved for use as monotherapy.

The FDA has approved a sublingual fi lm formulation of the nonergot dopamine agonist apomorphine (Kynmobi – Sunovion) for acute, intermittent treatment of "off" episodes in patients with Parkinson's disease (PD). A subcutaneous formulation of apomorphine (Apokyn) has been available for years for the same indication in patients with advanced PD.

View the Comparison Table: Drugs for Parkinson's Disease

The FDA has approved deutetrabenazine (Austedo – Teva), a vesicular monoamine transporter 2 (VMAT2) inhibitor, for treatment of chorea associated with Huntington's disease and, more recently, for treatment of tardive dyskinesia in adults. It is the second VMAT2 inhibitor to be approved for each of these indications; tetrabenazine (Xenazine, and generics) was approved earlier for Huntington's chorea and valbenazine (Ingrezza) was recently approved for treatment of adults with tardive dyskinesia.

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.

Since the introduction of fluoxetine (Prozac - Medical Letter, 30:45, 1988), bupropion (Wellbutrin - Medical Letter, 31:97, 1989), sertraline (Zoloft - Medical Letter, 34:47, 1992) and paroxetine (Paxil - this issue), the choice of an antidepressant has become more difficult. Should these widely prescribed new drugs replace tricyclic antidepressants such as amitriptyline (Elavil, and others), imipramine (Tofranil, and others), or nortriptyline (Aventyl, and others) for treatment of most patients with depression?

Interest in surgical treatment of Parkinson's disease has increased as the limitations of medical treatment have become apparent (Medical Letter, 35:31, 1993). Two approaches have been used. The first is transplantation of dopamine-producing cells into the patient's brain. The second is stereotactic surgery in areas of the brain that modify movement.