Antipsychotic Drug May Be Linked to Pituitary Tumors

As seen in this press release

A link may exist between the development of pituitary tumors and the use of some drugs commonly used to treat schizophrenia, according to research from Duke University Medical Center and the U.S. Food and Drug Administration (FDA). Although a connection has been suspected for more than 20 years, this is the first systematic study to document an association between specific antipsychotic medications and adverse reports of pituitary tumors in humans.

Of seven antipsychotic medications, risperidone (trade name Risperdal), was linked to 70 percent of pituitary tumors reported to the FDA's Adverse Events Reporting System database. Risperidone is the most widely used medication within the class of drugs called atypical antipsychotics, which are used to treat schizophrenia, paranoia and manic-depressive disorders, according to the study authors.

The findings appear in the June 2, 2006 issue of Pharmacotherapy. The study was funded by the author's respective research departments. Coauthors include lead author Ana Szarfman, Joseph Tonning and Jonathan Levine, all of the FDA. [...]

The team chose six atypical antipsychotics and one typical antipsychotic to examine in a "data mining" analysis using a sophisticated software algorithm. The algorithm, called the Multi-item Gamma Poisson Shrinker (MGPS), was used to "mine" data contained in the FDA's Adverse Event Reporting System (AERS) database. Using the algorithm software, the researchers looked for disproportionate reporting patterns of pituitary tumors linked to use of risperidone, aripiprazole, clozapine, olanzapine, quetiapine, ziprasidone and haloperidol, the typical antipsychotic.

They found 77 reports of pituitary tumors associated with the seven antipsychotics. Risperidone was associated with 54 (70 percent) of those reports and had the highest adjusted reporting ratio for pituitary tumors, followed by haloperidol and ziprasidone. Complications included nine reports of visual problems, two reports of convulsions, four reports of headaches, three reports of cerebrovascular events and seven reports of patients who needed surgical intervention. [...]

All reported side-effects were most strongly associated with risperidone, which also accounted for 82 percent of all reported occurrences of side-effects in children and adolescents. The researchers are concerned that development of pituitary tumors following chronic use of potent antipsychotics may pose a problem in mentally ill patients, particularly children.