Analgesic efficacy of inhaled morphine in patients after bunionectomy surgery.
BACKGROUND
The AERx Pain Management System (Aradigm Corporation, Hayward, CA) is a novel pulmonary delivery system for the systemic administration of morphine. The authors compared the relative analgesic efficacy and safety of the AERx Pain Management System with those of placebo and intravenous morphine in an orthopedic postsurgical pain model.


METHODS
Eighty-nine male and female PS-1 to PS-3 patients underwent standardized bunionectomy surgery and received multiple doses of inhaled or intravenous placebo, inhaled morphine (one inhalation [2.2 mg] or three inhalations [6.6 mg]), or intravenous morphine (4 mg) in a blinded fashion. Open-label rescue morphine (2 mg) was also available as needed. Pain intensity, pain relief, and time to pain relief were measured after the first dose. Global evaluation, morphine consumption, vital signs, and adverse events were monitored for 8 h after treatment. Blinded study personnel performed all treatment administrations and pain assessments.


RESULTS
Three inhalations of morphine and 4 mg intravenous morphine provided comparable single- and multiple-dose analgesia. One inhalation of morphine was statistically indistinguishable from placebo. Three inhalations of morphine and 4 mg intravenous morphine both consistently demonstrated significantly greater analgesic efficacy than did placebo and one inhalation of morphine.


CONCLUSIONS
Comparable analgesic efficacy was demonstrated between a carefully matched dose of inhaled and intravenous morphine in a postsurgical pain model.
Thipphawong
John B
JB
Aradigm Corporation, Hayward, California 94545, USA. ThipphawongJ@aradigm.com
Babul
Najib
N
Morishige
Richard J
RJ
Findlay
Hugh K
HK
Reber
Keith R
KR
Millward
Gary J
GJ
Otulana
Babatunde A
BA
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006215:Hallux Valgus / Q000601:surgery*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D009330:Nebulizers and Vaporizers; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*
D000701:Analgesics, Opioid; D009020:Morphine