Effect of ethinyl estradiol on the panic response to the panicogenic agent pentagastrin.

Panic disorder (PD) symptomatology has been reported to be altered by hormonal events or treatments which affect estrogen levels. Coryell et al. [Arch. Gen. Psychiatry, 39 (1982) 701-703; Am. J. Psychiatry, 143 (1986) 508-510] have suggested that the increased cardiovascular risk associated with PD is significantly greater in males, alluding to a potential cardioprotective effect of female hormones in the context of panic attacks. In the present study, we were, therefore, interested in elucidating the role of estrogen in modulating the behavioural and cardiovascular responses induced by the panicogenic agent pentagastrin, a cholecystokinin-B (CCK(B)) receptor agonist. A double-blind cross-over placebo-controlled design with randomization of the order of a 3-day pretreatment of ethinyl estradiol (EE) (50 microg/day) or placebo was used to assess the effect of a 30-microg i.v. bolus injection of pentagastrin on panic symptom intensity and on increases in heart rate (DeltaHR), systolic (DeltaSBP) and diastolic (DeltaDBP) blood pressure following each pretreatment. Subjects were 9 male healthy controls and 11 male PD patients. EE pretreatment did not significantly reduce the pentagastrin-induced panic symptom scale (PSS) scores and had no effect on DeltaDBP or DeltaSBP. EE did, however, attenuate the pentagastrin-induced increase in HR in both PD patients and healthy controls. Only male subjects were included in the present study; however, we are currently investigating the influence of female gonadal hormones on the panic response to pentagastrin in female PD patients and healthy controls. Our results suggest that estrogens may display cardioprotective effects in the context of panic attacks.