title: Antagonism of the respiratory and analgesic effect of fentanyl produced by aminophylline.
abstract: Low-dose aminophylline may reverse the respiratory depression caused by morphine and fentanyl. High-dose aminophylline may decrease an animal's tolerance to painful stimulation. We postulated that fentanyl combined with low-dose aminophylline could result in adequate analgesia without the side-effect of respiratory depression. Twelve healthy volunteers were randomly divided into group A and group B each consisting of six persons. Group A received fentanyl 3 ug/kg and group B received fentanyl 3 ug/kg plus aminophylline 3 mg/kg iv. Arterial carbon dioxide tension (PaCO2) was taken as an index of respiratory status and the analgesic effect of fentanyl was estimated by measuring changes in maximum pain tolerance (MPT) using a pressure clamp device. The results showed that 3 mg/kg of aminophylline significantly alleviated the respiratory depression effect of fentanyl 15 and 25 min post-injection (P less than 0.05), without attenuation of its analgesic effect. The severe hemodynamic disturbance and acute reversal of analgesia, which may be induced by naloxone, were not observed. Our results suggest that aminophylline safely reverses the respiratory depression caused by fentanyl.
authors.forename: R T
authors.initials: RT
authors.lastname: Ho
authors.forename: B
authors.initials: B
authors.lastname: Jawan
authors.forename: S T
authors.initials: ST
authors.lastname: Fung
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000628:Aminophylline / Q000097:blood / Q000494:pharmacology*; D000698:Analgesia; D005283:Fentanyl / Q000037:antagonists & inhibitors*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D012119:Respiration / Q000187:drug effects*
chemical_list: D000628:Aminophylline; D005283:Fentanyl