3.1.1 Tardive Dyskinesia
TD is an especially troublesome adverse
effect, in that it can frequently be irreversible.
In a prospective study of 118 FES patients who
were treated with typical APDs, the cumulative
incidence of TD in FES rose from 5% after 1 year
to nearly 16% after 4 years.[48] A purported advantage
of atypical APDs is that they confer less
risk of TD than typical APDs. A meta-analysis of
11 studies with patients taking atypical APDs
(n = 2769) and three studies of patients taking
haloperidol (n = 408) concluded that annualized
rates of TD were 0.8% for atypical APDs compared
with 5.4% for haloperidol.[8] In these studies,
higher relative doses of haloperidol (mean
>10 mg/day) may have contributed to the elevated
TD risk. Indeed, among five long-term
studies using risperidone, mean risperidone dosage
ranged from 1 to 4.9 mg/day and, similarly,
TD rates in risperidone-treated subjects varied
from 0% to 13.4%.[8]
Antipsychotic Drugs for
First-Episode Schizophrenia
A Comparative Review
CNS Drugs 2009; 23 (10): 837-855
1172-7047/09/0010-0837/$49.95/0