EFFECT OF CI-988 ON CHOLECYSTOKININ TETRAPEPTIDE-INDUCED PANIC SYMPTOMS IN HEALTHY-VOLUNTEERS

A randomized, placebo-controlled double-blind, three-way crossover des ign was used to evaluate the effectiveness of single oral 100 mg doses of CI-988, a cholecystokinin B (CCKB) antagonist in attenuating panic symptoms induced by intravenous injection of cholecystokinin-tetrapep tide (CCK-4). Thirty healthy men received the following treatments on three separate occasions: placebo capsules/placebo, placebo capsules/C CK-4, or CI-988 capsules/CCK-4. There was no marked difference in the number time to onset, or duration of panic symptoms between CI-988/CCK -4 and placebo/CCK-4. There was, however, a 14% difference in sum inte nsity scores between these treatments that was statistically significa nt (p = 0.039). The symptoms most affected by CI-988 were cold chills/ hot flushes, chest pain/discomfort, and anxiety/fear/apprehension. Pan ic attack frequency also decreased following CI-988 treatment (8/30 vs . 16/30; p = 0.035). This decrease, amid otherwise modest effects, cou ld be explained by a preferential effect of CI-988 on the subjective e xperience of anxiety/fear/apprehension. Possible reasons for the relat ively modest effects of CI-988 on CCK-4-induced panic symptoms are dis cussed.