Three patients (4 percent) discontinued treatment
before the eight-week follow-up. One patient
each in the risperidone and placebo groups withdrew
consent. The third patient, who was in the
risperidone group, had a serious adverse event.
His mental status deteriorated over one to two
weeks, he required frequent restraint, and his
creatine kinase level was elevated (with no evidence
of fever, rigidity, or autonomic instability). He had
a history of neuroleptic malignant syndrome related
to haloperidol. Treatment with the study
medication was stopped, and the patient was admitted
to a medical ward. He subsequently recovered
fully, from a medical perspective, and his
mental status returned to the prestudy level of
symptoms. Two other serious adverse events were
reported, both during the extension phase of the
study, when clozapine plus open-label risperidonewas administered. One patient had an exacerbation
of auditory hallucinations and suicidal ideation,
requiring admission to the hospital. Poor adherence
with treatment was suspected, and these
symptoms had occurred before the patient entered
the trial. A second patient had a self-inflicted
scalp laceration that required stitches. There was
a history of similar behavior involving head banging
before the trial.