"The incidence of allergic reactions to antipsychotic agents is not well known but would be expected to be low. However, pharmacy records at a large state psychiatric hospital indicated surprisingly high rates of such allergies," scientists in the United States report (see also Allergies).

"We hypothesized that these high rates of reported allergies in the pharmacy database would not be supported by clinical history, but rather that they represented other side effects or past uncritical acceptance of casual patient reports. listed as having experienced allergies to antipsychotic medications were interviewed by two psychiatrists and any clinical evidence that suggested an allergy was noted. Of 585 patients who were hospitalized on the day the data were reviewed, 138 patients (23.6%) were identified by the pharmacy as allergic to an antipsychotic medication, 79 of whom were available and consented to be interviewed. Of these 79 patients, 7 (8.9%) provided evidence of a true allergy and 12 (15.2%) provided evidence that suggested a remote possibility of an allergy. Of the 60 ''allergic'' patients who provided no evidence of an allergy, 57% reported a non-allergic adverse drug reaction (ADR) that may have accounted for the allergy assignment and 32% reported possible symptoms that might have done so. Length of stay was possibly associated with an unsupported allergy designation (p < 0.07). Reported allergies to other psychotropic agents (p < 0.02) or to nonpsychotropic agents (p < 0.07) were associated with evidence of a ''true'' allergy to an antipsychotic agent. Allergies to antipsychotic medications may be much less common than suggested by clinical records," wrote J.R. Nurenberg and colleagues.

The researchers concluded: "The examination of focused clinical histories from patients who have been reported to experience such ''allergies'' would likely expand the pool of available medications for many patients. (Journal of Psychiatric Practice 2009;15:489-492)."

Nurenberg and colleagues published their study in the Journal of Psychiatric Practice (Reported Allergies to Antipsychotic Agents in a Long-Term Psychiatric Hospital. Journal of Psychiatric Practice, 2009;15(6):489-492).

For more information, contact J.R. Nurenberg, Greystone Pk Psychiatry Hospital, 59 Koch Avenue, Morris Plains, NJ 07950, USA.

Publisher contact information for the Journal of Psychiatric Practice is: Lippincott Williams & Wilkins, 530 Walnut St., Philadelphia, PA 19106-3621, USA.