Hyperventilation associated with quetiapine.
OBJECTIVE: To describe a case of hyperventilation associated with the administration of quetiapine. CASE SUMMARY: A 69-year-old African-American woman admitted to a psychiatric hospital for treatment of major depression with psychotic features was treated and successfully discharged with quetiapine, along with metronidazole and miconazole to treat bacterial/monilial vaginitis. Three days after discharge, the patient presented to a community hospital with shortness of breath and hyperventilation. The patient was admitted and treated for tachypnea and acute respiratory alkalosis. During this hospitalization, the patient was noted to have increased respiratory rate following the administration of quetiapine. DISCUSSION: Hyperventilation was reported during the clinical trials of quetiapine; however, this is the first published report to date. Serotonin is involved both centrally and peripherally in the regulation of respiration. A contributing factor in this case may have been the concomitant administration of metronidazole, which inhibits the cytochrome P450 enzyme (CYP3A4) also responsible for the metabolism of quetiapine. CONCLUSIONS: The development of hyperventilation and respiratory alkalosis was associated with the administration of quetiapine.