Betahistine Lessens Olanzapine-Induced Weight Gain, Sleepiness
Administering betahistine along with olanzapine may help reduce medication-induced weight gain and sleepiness in patients with schizophrenia, suggests a study involving healthy participants in the March Journal of Psychopharmacology.
“Olanzapine is also a potent histamine-H1 antagonist that results in weight gain and somnolence,” researchers wrote. “Betahistine is a centrally acting histamine-H1 agonist, and therefore may reduce olanzapine’s effect on histamine receptors in the brain.”
Researchers investigated the safety and effects of betahistine-olanzapine coadministration in 48 healthy women. Participants were randomly assigned to receive either 144 milligrams per day of betahistine or placebo for 4 weeks. The high dose of betahistine was necessary, the researchers explained, due to “olanzapine’s high affinity for the histamine-H1 receptor.”
In light of the high dose of betahistine, researchers waited until the second week of the study to begin administration of olanzapine, titrating up to 10 milligrams per day. Coadministration of the medications continued for an additional 2 weeks.
At the end of the 4-week intervention, women who received betahistine gained an average 37% less than women who received placebo — 1.24 kilograms compared with 1.93 kilograms, researchers found. Increases in daytime Epworth Sleepiness Scale scores, meanwhile, were on average 60% lower among women who received betahistine compared with women who did not. The betahistine group averaged score increases of 1.82 units, while the placebo group averaged increases of 3.57 units.
Since the study found no significant differences in adverse events between the groups, researchers recommended betahistine-olanzapine coadministration be tested next in a patient cohort.
—Jolynn Tumolo
Reference
Psych Topics:
Schizophrenia & Psychotic Disorders