Oral antipsychotic drugs used for treatment of schizophrenia, schizoaffective disorder, delusional disorder, and other manifestations of psychosis or mania are listed in Table 1. Parenteral antipsychotic drugs used for treatment of these disorders are listed in Table 2.

The FDA has approved two new long-acting injectable formulations of second-generation antipsychotics for treatment of schizophrenia: aripiprazole lauroxil (Aristada – Alkermes), which is given once every 4-6 weeks, and paliperidone palmitate (Invega Trinza – Janssen), which is given once every 3 months. Once-monthly injectable formulations of aripiprazole (Abilify Maintena) and paliperidone palmitate (Invega Sustenna) were approved earlier.

The FDA has approved an inhalation powder formulation of loxapine (Adasuve – Teva), a first-generation antipsychotic long available in an oral formulation, for treatment of acute agitation related to schizophrenia or bipolar I disorder in adults. Adasuve is the first inhaled drug to be approved for this indication.

Drugs are not the only treatment for psychiatric illness. Psychotherapy remains an important component in the management of these disorders, and cognitive behavioral therapy (CBT) can be used for many of them as well. Electroconvulsive therapy (ECT) has a long history of efficacy and safety when drugs are ineffective or cannot be used.

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 required the manufacturer of the secondgeneration antipsychotic quetiapine (Seroquel) to add a warning to the labeling saying that use of the drug should be avoided in combination with other drugs that prolong the electrocardiographic QTc interval (Table 1). The warning is based only on postmarketing reports of QT-interval prolongation in patients who overdosed on the drug, had concomitant illness, or were taking other drugs known to cause electrolyte imbalances or increase the QT interval. QT prolongation can lead to torsades de pointes, a potentially fatal cardiac arrhythmia.

Asenapine (Saphris - Schering-Plough), a dibenzo-oxepino pyrrole, has been approved by the FDA in a sublingual tablet formulation for acute treatment of schizophrenia and manic or mixed episodes associated with bipolar disorder. It is the sixth second-generation antipsychotic approved by the FDA for use in bipolar disorder.

Dronedarone (Multaq - Sanofi-Aventis) has been approved by the FDA for oral treatment of atrial fibrillation and flutter. Amiodarone (Cordarone, and others) is the most effective drug for this indication, but has considerable toxicity.

A recently published retrospective cohort study in patients 30-74 years old has led to headlines in the media warning that use of atypical antipsychotic drugs doubles patients’ risk of sudden cardiac death. Typical antipsychotics have long been associated with this risk. In this study, however, the incidence of sudden cardiac death was similar with typical and atypical antipsychotics: about 1 in 340 person-years among the patients who took typical (first generation) antipsychotics such as haloperidol (Haldol, and others) and 1 in 360 personyears among those who took atypical (second-generation) drugs such as olanzapine (Zyprexa), compared to 1 in 700 patient-years among otherwise similar nonusers of antipsychotic drugs. The risk increased with the dose of the drug and also with the age of the patient; the authors state that they did not include patients younger than 30 because sudden cardiac death is very rare in the younger age group.1

Second-generation drugs are less likely than first generation drugs to cause extrapyramidal symptoms, tardive dyskinesia and neuroleptic malignant syndrome, but more likely to cause weight gain and other metabolic abnormalities.2 Aripiprazole (Abilify)3 is least likely to prolong the QT interval, which is one of the mechanisms that could be responsible for the small increase in the absolute risk of sudden death among patients who take antipsychotic drugs.

In a patient with a good indication for its use, the consequences of not taking an antipsychotic drug may be greater than the risks of taking one.

1. WA Ray et al. Atypical antipsychotic drugs and the risk of sudden cardiac death. N Engl J Med 2009; 360:225.
2. Drugs for psychiatric disorders. Treat Guidel Med Lett 2006; 4:35.
3. Second-generation antipsychotics — aripiprazole revisited. Med Lett Drugs Ther 2005; 47:81.

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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.

The FDA recently cleared the AmpliChip CYP450 Test (Roche), which analyzes blood-derived DNA to detect genetic variations in the activity of cytochrome P450 (CYP) enzymes CYP2D6 and CYP2C19 and determines the metabolizer status of the patient. The test is intended to help guide clinicians in prescribing individualized drug therapy. About 25% of all drugs, including many antidepressants and antipsychotics, are substrates of either CYP2D6 or CYP2C19. The test is being promoted initially to psychiatrists.

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 olanzapine/fluoxetine combination (Symbyax). The manufacturers of all of these drugs will be required to add a "black box" warning to their labeling.

A recent supplement to the Journal of Clinical Psychiatry, titled "The Expert Consensus Guideline Series: Optimizing Pharmacologic Treatment of Psychotic Disorders," concluded that most experts endorsed use of second-generation (atypical) antipsychotics rather than first-generation drugs, with risperidone (Risperdal - Janssen) the top choice for first episodes, multiple episodes or switches from another drug (JM Kane et al, J Clin Psychiatry 2003; 64 suppl 12:5). The supplement was sponsored by Janssen.

The number of drugs marketed for psychiatric indications has increased sharply in recent years. The recommendations in this article are based on the results of controlled trials and on the experience and opinions of Medical Letter consultants. Interactions with other drugs can be found in The Medical Letter Handbook of Adverse Drug Interactions, 2003.

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.

Aripiprazole (Abilify - Bristol-Myers Squibb/Otsuka), a quinolinone derivative, has been approved by the FDA for treatment of schizophrenia.

Quetiapine (Seroquel - Zeneca), a dibenzothiazepine derivative, has been approved by the FDA for treatment of schizophrenia and other psychotic disorders. It is a new addition to the 'atypical' antipsychotics, which include olanzapine (Zyprexa - Medical Letter, 39:5, 1997), risperidone (Risperdal) and clozapine (Clozaril). Atypical antipsychotic drugs generally are less likely to cause extrapyramidal symptoms than older drugs such as haloperidol (Haldol, and others) or the phenothiazines.

The number of new drugs marketed for psychiatric indications has increased sharply in recent years. The recommendations in this article are based on the results of controlled trials and on the experience and opinions of Medical Letter consultants. Interactions with other drugs can be found in The Medical Letter Handbook of Adverse Drug Interactions, 1997.

Olanzapine (Zyprexa - Lilly), a thienobenzodiazepine that structurally resembles and binds to many of the same receptors as clozapine (Clozaril), is now available in the USA for treatment of schizophrenia and other psychotic disorders.

Risperidone (Risperdal - Janssen), a benzisoxazole derivative, is now available in the USA for treatment of schizophrenia and other psychotic disorders.

Zolpidem (Ambien - Searle), an imidazopyridine hypnotic available in Europe for several years, was recently approved by the US Food and Drug Administration for short-term treatment of insomnia.

In the short time since fluoxetine (Prozac - Lilly) first became available in the USA (Medical Letter, 30:45, 1988), it has become the most frequently prescribed of all antidepressants. Some recent reports, however, have questioned its safety.

Clozapine (Clozaril - Sandoz), a dibenzodiazepine antipsychotic drug that has been available in Europe for many years, was recently approved for marketing by the US Food and Drug Administration. Because of its toxicity, the labeling for clozapine recommends using the drug only for schizophrenic patients who have not responded adequately to standard antipsychotic drugs or have had intolerable adverse effects.

Nabilone (Cesamet - Lilly), a synthetic cannabinoid chemically related to tetrahydrocannabinol (THC), the main active ingredient in marijuana, was recently marketed in the USA for oral treatment of nausea and vomiting associated with cancer chemotherapy. Oral THC itself, known generically as dronabinol (Marinol), is also commercially available as an antiemetic for cancer patients (Medical Letter, 27:97, 1985). Other drugs used for this purpose include metoclopramide (Reglan - Medical Letter, 24:67, 1982), prochlorperazine (Compazine; and others), haloperidol (Haldol; and others), and corticosteroids. Benzodiazepines, such as lorazepam (Ativan; and others), are used to treat anticipatory nausea and vomiting that occurs before chemotherapy begins.