Objective: Antipsychotic-induced akathisia can be distressing and unendurab
le for prolonged periods. It has been shown that intramuscular biperiden is
a relatively rapid and effective treatment for akathisia. However, the int
ravenous administration of biperiden may provide a more rapid effect, altho
ugh this remains to be definitively proven. Method; The subjects obtained f
or this study met the diagnostic criteria for schizophrenia as defined by t
he Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The ther
apeutic effect of i.v. and i.m. biperiden was studied in an open clinical t
rial in twenty-three (12 male and 11 female) patients who developed antipsy
chotic-induced acute akathisia as defined by the research criteria of the D
SM-IV. Following the development of akathisia, 5 mg of biperiden was intrav
enously injected in seventeen patients and intramuscularly in six patients.
The therapeutic effect of biperiden on akathisia was clinically assessed b
y using the rating scale of Barnes. Results: Following i.v. administration
on biperiden, the meantime to onset and maximum effect occurred 1.6 (SD = 1
.9) and 9.2 minutes (SD = 6.0), respectively. Furthermore, at the time of m
aximal effect, akathisia was completely ameliorated in all patients. The si
de effects reported were mild and transient. Following i.m. administration,
the mean time to onset and maximum effect were 30.5 (SD = 5.9) and 50 minu
tes (SD = 7.4), respectively. Thus, the time to maximal effect was signific
antly less (40 minutes) alter i.v. compared to i.m. administration. Conclus
ion: These results suggest that i.v. administration of 5 mg of biperiden co
uld be used to provide a rapid and effective treatment for patients with se
vere akathisia.