Weight Gain | Diabetes | Dyslipidemias
The metabolic side effects of clozapine are prominent (Henderson 2001; D. A. Wirshing et al. 1998, 1999). Weight
gain has been observed in both premarketing and postmarketing trials
(Henderson 2001; Simpson and Varga 1974).
In patients observed in various clinical trials in our laboratory,
the average weight gain in a 6-month period with clozapine treatment
was 6.9 ± 0.8 kg. Allison et al. (1999) performed a meta-analysis of the weight-gain data
in short-term trials of medications. The average weight gain observed
with clozapine was 4.45 kg, which exceeded the weight gain observed
with all of the other medications in the study, including the conventional
agent thioridazine (3.19 kg), a medication known for its weight-gain
liability. The weight gain observed with clozapine seems to occur
for a prolonged period of time—up to 40 weeks. In one naturalistic
study, Henderson (2001) observed patients in a clozapine
clinic for 5 years and noted weight gain occurring for up to 46
months in some patients.