Actigraphic measurement of the effects of single-dose haloperidol and olanzapine on spontaneous motor activity in normal subjects.
OBJECTIVE
To quantitatively examine the effects of haloperidol and olanzapine on spontaneous motor activity in normal subjects.


METHODS
Randomized, double-blind, placebo-controlled medication study.


METHODS
Normal volunteers (n = 30).


METHODS
Subjects received 1 dose of either haloperidol 2 mg (n = 9), olanzapine 10 mg (n = 10) or placebo (n = 10) and were admitted to hospital for the next 24 hours.


METHODS
Subjects wore an actigraphic monitor, which recorded movement in 15-second epochs. The Simpson-Angus Extrapyramidal Side Effect Scale (SAS) and the Barnes Akathisia Scale (BAS) were administered before and 7 and 24 hours after medication was given.


RESULTS
Compared with placebo, total motor activity was decreased by 41% with olanzapine (p = 0.004) and by 12% with haloperidol (NS). There were significantly more epochs with zero movement with olanzapine than with haloperidol or placebo. For non-zero epochs, the mean activity count and the distribution of activity counts did not differ significantly among groups. There were no positive findings on the SAS or the BAS.


CONCLUSIONS
Olanzapine decreased total motor activity by increasing the amount of time during which subjects were immobile, rather than by affecting the magnitude of movement during periods in which there was activity. This effect occurred at a dose of olanzapine low enough not to cause clinically observed extrapyramidal side effects. Our results suggest that actigraphy is useful as a sensitive, noninvasive tool for measuring the effect of antipsychotics on spontaneous motor activity.
Kiang
Michael
M
Schizophrenia Division, Centre for Addiction and Mental Health, Department of Psychiatry, University of Toronto, Toronto, Ont.
Daskalakis
Z Jeff
ZJ
Christensen
Bruce K
BK
Remington
Gary
G
Kapur
Shitij
S
D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology*; D001569:Benzodiazepines; D004311:Double-Blind Method; D006220:Haloperidol / Q000009:adverse effects / Q000494:pharmacology*; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity / Q000187:drug effects*; D009127:Muscle Rigidity / Q000139:chemically induced; D000077152:Olanzapine; D010890:Pirenzepine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology*; D011569:Psychiatric Status Rating Scales
D014150:Antipsychotic Agents; D001569:Benzodiazepines; D010890:Pirenzepine; D006220:Haloperidol; D000077152:Olanzapine