Glucosamine sulfate in the treatment of knee osteoarthritis symptoms: a randomized, double-blind, placebo-controlled study using acetaminophen as a side comparator.
OBJECTIVE
To assess the effects of the prescription formulation of glucosamine sulfate (1,500 mg administered once daily) on the symptoms of knee osteoarthritis (OA) during a 6-month treatment course.


METHODS
Three hundred eighteen patients were enrolled in this randomized, placebo-controlled, double-blind trial in which acetaminophen, the currently preferred medication for symptomatic treatment of OA, was used as a side comparator. Patients were randomly assigned to receive oral glucosamine sulfate 1,500 mg once daily (n = 106), acetaminophen 3 gm/day (n = 108), or placebo (n = 104). The primary efficacy outcome measure was the change in the Lequesne index after 6 months. Secondary parameters included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and response according to the Osteoarthritis Research Society International criteria. These outcome measures were assessed using an intent-to-treat analysis.


RESULTS
At baseline, the study patients had moderately severe OA symptoms (mean Lequesne index approximately 11 points). Glucosamine sulfate was more effective than placebo in improving the Lequesne score, with a final decrease of 3.1 points, versus 1.9 with placebo (difference between glucosamine sulfate and placebo -1.2 [95% confidence interval -2.3, -0.8]) (P = 0.032). The 2.7-point decrease with acetaminophen was not significantly different from that with placebo (difference -0.8 [95% confidence interval -1.9, 0.3]) (P = 0.18). Similar results were observed for the WOMAC. There were more responders to glucosamine sulfate (39.6%) and acetaminophen (33.3%) than to placebo (21.2%) (P = 0.004 and P = 0.047, respectively, versus placebo). Safety was good, and was comparable among groups.


CONCLUSIONS
The findings of this study indicate that glucosamine sulfate at the oral once-daily dosage of 1,500 mg is more effective than placebo in treating knee OA symptoms. Although acetaminophen also had a higher responder rate compared with placebo, it failed to show significant effects on the algofunctional indexes.
Herrero-Beaumont
Gabriel
G
Rheumatology Department, Fundación Jiménez Díaz-Capio, Madrid, Spain. gherrero@fjd.es
Ivorra
José Andrés Román
JA
Del Carmen Trabado
María
M
Blanco
Francisco Javier
FJ
Benito
Pere
P
Martín-Mola
Emilio
E
Paulino
Javier
J
Marenco
José Luis
JL
Porto
Armando
A
Laffon
Armando
A
Araújo
Domingos
D
Figueroa
Manuel
M
Branco
Jaime
J
D000082:Acetaminophen / Q000627:therapeutic use*; D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005944:Glucosamine / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000188:drug therapy*; D011446:Prospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome
D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen; D005944:Glucosamine