Responses to hypercarbia induced by acetazolamide in panic disorder patients.

CO2 inhalation has been reported to induce panic attacks in panic disorder patients. State anxiety, somatic symptoms of anxiety, physiological changes, and cerebral blood flow (CBF) were monitored in panic disorder patients before and after intravenous injections of 1 g of acetazolamide (13 patients) and saline (10 patients), given under double-blind conditions. In spite of significant hypercarbia, as evidenced by increased CBF in the former group, only one subject reported panic and even that attack did not meet DSM-III-R criteria. There was only one significant difference between the drug and placebo groups; the acetazolamide group experienced significantly more dizziness.