Quetiapine Widely Used Off-Label in Psychiatric Inpatients in Single-Site Study

May 24, 2007 (San Diego) — A recent study found that among patients in a psychiatric hospital, the atypical antipsychotic quetiapine (Seroquel, AstraZeneca), which is approved for schizophrenia and bipolar disorder, was extensively used off-label. It was commonly used in lower-than-approved doses and for depression, agitation, or insomnia in patients without schizophrenia or bipolar disorder.

These findings were presented here in a poster at the American Psychiatric Association 2007 Annual Meeting.

Lead author Noah S. Philip, MD, from Brown University, in Providence, Rhode Island, told Medscape: "The majority of people who received off-label quetiapine were people with depressive disorders. . . . At the same time, what is interesting is that even among people who had schizophrenia or bipolar spectrum disorders, relatively few (around half) actually received the dose that the Food and Drug Administration [FDA] has established as the effective dose: 300 to 800 mg."

The group writes that quetiapine is generally well tolerated, with a low risk for extrapyramidal symptoms, and clinicians cite that they use it for its low abuse potential, mild sedation with low risk of confusion, and modest cardiovascular effects. They add that this drug, like other atypical neuroleptics, has been associated with weight gain and dyslipidemia and carries a black-box warning for stroke risk in the elderly.

Dr. Philip said that in his clinical experience, off-label use of quetiapine at low doses for agitation and insomnia is widespread, yet "there's no report in the literature showing either that it's efficacious or really that it's safe in those low doses."

He and colleagues hypothesized that quetiapine was extensively used for agitation, anxiety, and insomnia in a wide variety of diagnoses and in low-dose regimens. To investigate this, they conducted a retrospective utilization review of the prescribing practices of this drug at Butler Hospital, an acute-care psychiatric hospital.

They examined pharmacy dispensing records from October 2004 to March 2006 to find prescriptions for quetiapine — either standing orders or orders to give the drug as needed — for inpatients. The researchers collected information about daily dose and discharge diagnoses for the patients who had a standing order, and they noted the dose frequency and behavior indication for the patients who received as-needed dosing.

Standing Dose vs As-Needed Dose

During the study period, 738 patients (49% male) received a standing dose of quetiapine and 1335 patients (53% male) received as-needed doses. The most common diagnoses, in decreasing order of prevalence, were depression, substance-related abuse, bipolar disorder, and psychotic disorder.

Patients who had a standing order for quetiapine received a mean of 169 ± 154 mg/day (median, 200 mg/day), and only 29.8% received at least 300 mg/day. In the small proportion (28.5%) of patients receiving a standing dose of quetiapine who had an FDA-approved indication, less than half received at least 300 mg/day.

Patients who were prescribed quetiapine as needed most commonly received 50 mg every 1 to 2 hours for agitation, agitation/anxiety, or insomnia. Only 17.4% of the patients receiving the drug as needed had a diagnosis of bipolar or psychotic disorders.

Further Research Needed

The group writes that since the most prominent as-needed indication for quetiapine was agitation, the drug was likely being used when benzodiazepines and/or typical neuroleptics were contraindicated. They add that quetiapine was being ordered at bedtime probably for its sedative-hypnotic properties.

The investigators conclude that, as hypothesized, they did find extensive off-label use of quetiapine. They write that "further research is needed on the safety and range of efficacy of quetiapine in nonapproved doses and diagnoses." Dr. Philip added: "We need to take a closer look at some of these patients and what we are doing."

Two study authors received some support for this study from the National Alliance for Research on Schizophrenia and Depression. None received funding or support from AstraZeneca for this study, but 2 authors received honoraria from the company for educational activities unrelated to this study. This paper will be published in an upcoming issue of the Annals of Clinical Psychiatry.

American Psychiatric Association 160th Annual Meeting: Abstract NR36. May 19-24, 2007.

Medscape Medical News © 2007  Medscape

Cite this: Marlene Busko. Quetiapine Widely Used Off-Label in Psychiatric Inpatients in Single-Site Study - Medscape - May 24, 2007.