Side Effects of Antipsychotic Drugs

Estimates by David N. Osser, M.D. from analysis of the evidence, February 25, 2002. Estimates assume use of full antipsychotic doses.

Item  Typical AD's Clozapine  Risperidone Olanzapine Quetiapine Ziprasidone
EPS some - +++  0  + ( less if <4mg)  0-+ (if <10mg)  0  0 - +
Tardive Dyskinesia ++ - +++  0 - rare  rare  rare rare rare
Seizures rare - 0.3%  2-10%  ~0.3%  ~0.9%   ~0.8%  ~0.4%
Sedation some - +++  +++  +  ++  ++  0-+
Orthostasis  some - +++  +++  ++  +  +++  + - ++
Cardiac Conduction  + - +++  + - ++  +  +  + - ++  ++
Increased LFT's  some - ++  ++  0 - +  ++  ++  0 - +
Anticholinergic  some - +++  +++  0  0 - +  0  0
 Agranulocytosis  ~1 in 50,000 4 in 1000  ~ 1 in 50,000  ~1 in 50,000  ~1 in 50,000  ~1 in 50,000
 Prolactin Elevation  ++ - +++  transient  +++  0 - +  0  0 - +
 Weight Gain  some - ++  12lbs. avg./10wks  4 lbs. avg./ 6wks  12lbs. avg./12wks  6lbs. avg./6wks  0
Focal Cataracts   0?  0?  0?  0?  some risk  0?
 Metabolized by CYP...  various  1A2, 2D6, 3A4  2D6  1A2, 2D6 3A4 3A4
 Diabetes Exacerbation  + - ++  +++  +  +++  ++  0
 Hypertriglyceridemia  + - ++  +++  +  +++  ++  0