Atropine for the treatment of biliary tract pain: a double-blind, placebo-controlled trial.
OBJECTIVE
To compare the efficacy of IM atropine with placebo for the treatment of pain caused by biliary tract disease.


METHODS
Prospective randomized, double-blind, crossover study.


METHODS
Emergency departments of a university medical center and affiliated county hospital.


METHODS
Fifty-five adults with biliary tract disease.


METHODS
Subjects were randomized to receive either 0.6 mg (0.5 mL) IM atropine or normal saline placebo in a double-blinded manner. If pain relief with the initial injection was inadequate, patients received the alternate injection. Pain was assessed by visual analog scale (0 to 100 mm) before the initial injection and 30 to 40 minutes after each subsequent injection.


RESULTS
Relief of pain was complete after the initial injection in four of 28 (14%) who received atropine and four of 27 (15%) who received normal saline (P = .956). For subjects who received both injections, atropine and placebo resulted in similar pain relief (-12.0 mm versus -16.0 mm; P = .316). There also was no difference in pain relief between atropine and placebo for the subset of patients with biliary colic receiving both injections (-15.2 mm versus -17.0 mm; P = .658). This study had more than 80% power to detect a 7.5-mm difference in pain relief between atropine and placebo in all patients with biliary tract disease and a 12.5-mm difference in those with biliary colic.


CONCLUSIONS
Atropine is no better than placebo in the treatment of biliary tract pain.
Rothrock
S G
SG
Department of Emergency Medicine, Orlando Medical Center, Florida.
Green
S M
SM
Gorton
E
E
D000328:Adult; D001285:Atropine / Q000627:therapeutic use*; D001660:Biliary Tract Diseases / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy*; D010147:Pain Measurement; D011446:Prospective Studies
D001285:Atropine