M. Kellner et al., INFLUENCE OF CLONIDINE ON PSYCHOPATHOLOGICAL, ENDOCRINE AND RESPIRATORY EFFECTS OF CHOLECYSTOKININ TETRAPEPTIDE IN PATIENTS WITH PANIC DISORDER, Psychopharmacology, 133(1), 1997, pp. 55-61
The influence of clonidine pretreatment on psychopathological, endocri
ne and respiratory effects of cholecystokinin tetrapeptide (CCK-4) was
characterized. Patients with panic disorder (DSM-III-R) were given 50
mu g CCK-4 IV at 1100 hours on 2 separate study days. In a randomized
double-blind design they were additionally infused with 150 mu g clon
idine or placebo from 1040 to 1110 hours. After CCK-4 all patients exp
erienced symptom attacks. No effects of clonidine on panic psychopatho
logy or blood gas parameters were observed, After CCK-4, in the clonid
ine condition the pituitary release of adrenocorticotropin (ACTH) and
prolactin was seemingly enhanced compared to placebo, Our results sugg
est that CCK-4-induced panic attacks are not suppressible by presynapt
ic alpha-2 receptor stimulation. Moreover, they point to a synergistic
postsynaptic action of clonidine to CCK-4 upon pituitary hormone secr
etion. The diverging sites of action might possibly explain the discre
pancies of psychopathological alterations and stress hormone secretion
.