Influence of clonidine on psychopathological, endocrine and respiratory effects of cholecystokinin tetrapeptide in patients with panic disorder

Psychopharmacology (Berl). 1997 Sep;133(1):55-61. doi: 10.1007/s002130050371.


The influence of clonidine pretreatment on psychopathological, endocrine and respiratory effects of cholecystokinin tetrapeptide (CCK-4) was characterized. Patients with panic disorder (DSM-III-R) were given 50 micrograms CCK-4 i.v. at 1100 hours on 2 separate study days. In a randomized double-blind design they were additionally infused with 150 micrograms clonidine or placebo from 1040 to 1110 hours. After CCK-4 all patients experienced symptom attacks. No effects of clonidine on panic psychopathology or blood gas parameters were observed. After CCK-4, in the clonidine condition the pituitary release of adrenocorticotropin (ACTH) and prolactin was seemingly enhanced compared to placebo. Our results suggest that CCK-4-induced panic attacks are not suppressible by presynaptic alpha-2 receptor stimulation. Moreover, they point to a synergistic postsynaptic action of clonidine to CCK-4 upon pituitary hormone secretion. The diverging sites of action might possibly explain the discrepancies of psychopathological alterations and stress hormone secretion.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adrenergic alpha-Agonists / therapeutic use*
  • Adrenocorticotropic Hormone / blood
  • Adult
  • Clonidine / therapeutic use*
  • Double-Blind Method
  • Female
  • Growth Hormone / blood
  • Humans
  • Hydrocortisone / blood
  • Male
  • Middle Aged
  • Panic Disorder / chemically induced
  • Panic Disorder / drug therapy*
  • Panic Disorder / psychology
  • Prolactin / blood
  • Respiration / drug effects*
  • Tetragastrin / adverse effects*


  • Adrenergic alpha-Agonists
  • Tetragastrin
  • Adrenocorticotropic Hormone
  • Prolactin
  • Growth Hormone
  • Clonidine
  • Hydrocortisone