Respiratory depression caused by low dose of olanzapine: A case report

Objective

Olanzapine is widely used throughout the world to treat patients with schizophrenia and bipolar disorder. Olanzapine has numerous side effects, but respiratory depression has not been reported with doses as low as 5 mg.

Clinical case

An elderly woman presented with severe hypercarbia, hypoxia, and impaired consciousness possibly due to low doses of oral olanzapine. There is no accepted antidote for the side effects of olanzapine, so we followed the patient with respiratory support and electrolyte correction. Symptoms improved after 2 weeks and did not recur.

Results and conclusions

Elderly patients, women, and non-smokers may have elevated olanzapine concentrations and may do better with lower than usual doses. If somnolence is observed in a patient taking olanzapine, a blood gas should be obtained and appropriate respiratory care should be provided. We expect that this case report will add to the existing body of literature on the appropriate use of olanzapine.