title: Influence of tramadol on the ventilatory response to hypoxia in humans.
abstract: We studied the effect of tramadol on the ventilatory response to 7 min acute isocapnic hypoxia (SpO2 85.1 (SD 0.4)%) during steady mild hypercapnia (PE'CO2 0.7 kPa above normoxic baseline) in 14 healthy volunteers (seven male). The acute hypoxic response was measured before and 1 h after oral placebo or tramadol (100 mg). After tramadol, ventilation during mild hypercapnia (mean 11.28 litres min-1) was significantly less (P < 0.05) than during placebo baseline (13.93 litres min-1), tramadol baseline (14.63 litres min-1), or after placebo (14.95 litres min-1), confirming that tramadol has a small depressive effect on the hypercapnic ventilatory response. There was no significant difference in the hypoxic ventilation/SpO2 response (1 min-1 %-1) measured during the placebo baseline (0.99), placebo (1.18), tramadol baseline (0.78) or tramadol (0.68) runs. These data suggest that tramadol does not depress the hypoxic ventilatory response.
authors.affiliation: Department of Medical and Radiological Science, University of Edinburgh, Royal Infirmary, UK.
authors.forename: P M
authors.initials: PM
authors.lastname: Warren
authors.forename: J H
authors.initials: JH
authors.lastname: Taylor
authors.forename: K E
authors.initials: KE
authors.lastname: Nicholson
authors.forename: P K
authors.initials: PK
authors.lastname: Wraith
authors.forename: G B
authors.initials: GB
authors.lastname: Drummond
mesh_terms: D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000188:drug therapy*; D000860:Hypoxia / Q000188:drug therapy*; D008297:Male; D012119:Respiration / Q000187:drug effects*; D014147:Tramadol / Q000627:therapeutic use*
chemical_list: D000701:Analgesics, Opioid; D014147:Tramadol