Comparable clinical outcomes between glucosamine sulfate-potassium chloride and glucosamine sulfate sodium chloride in patients with mild and moderate knee osteoarthritis: a randomized, double-blind study.

BACKGROUND: Glucosamine sulfate has been recommended for treatment of knee osteoarthritis in several published guidelines. However, there are various preparations of glucosamine that may result in different pharmacokinetic and clinical outcomes.

OBJECTIVES: Comparison of clinical outcomes of two different preparations of glucosamine sulfate (Sodium chloride salt and Potassium chloride salt) in patients with mild and moderate degree knee osteoarthritis. Laboratory tests to monitor drug safety were also studied.

MATERIAL AND METHOD: Patients with symptomatic mild and moderate degree knee osteoarthritis were randomly assigned to receive treatment with either glucosamine sulfate with potassium salt (GS-K) 1500 mg daily or glucosamine sulfate with sodium salt (GS-Na) 1500 mg daily. Types of treatments were blinded to both patients and evaluators. Clinical assessments were done two weeks prior to initiation of treatment and then every four weeks until the sixteen week of treatment. Standing knee radiographs were taken at the initial visit. Patients with Ahlback stage 1 to 4 were included in the current study. Clinical data included range of motion, presence or absence of joint effusion, WOMAC and SF36. Laboratory studies were also done to evaluate drug safety, including BUN, creatinine, electrolytes, and liver function test. Adverse drug reactions were also recorded.

RESULTS: Ninety patients with mild and moderate knee osteoarthritis (Ahlback grade 1-4) were randomized to two treatment groups, forty-five patients each. Demographic data and initial clinical assessment were similar in both groups. Both groups demonstrated improvement of WOMAC score and SF-36 at final follow-up but this did not reach statistical significance. Differences of WOMAC score and SF-36 between the two groups were not significant at any follow-up visit. Serum potassium level increased more significantly in the GS-K group but did not exceed normal value.

CONCLUSION: In this short-term randomized comparison, glucosamine sulfate with potassium salt (GS-K) is as effective in pain relief and as safe as glucosamine sulfate with sodium salt (GS-Na) for treatment of mild and moderate degree knee osteoarthritis.