To assess the efficacy and safety of glucosamine as a treatment for osteoarthritis.

MMEDLINE was searched from January 1965 to May 1997 using the keywords 'osteoarthritis', 'osteoarthrosis', 'gonarthrosis' and 'glucosamine'. In addition, the references cited in the retrieved articles were reviewed for additional studies.

Study designs of evaluations included in the review

Randomised controlled trials (RCTs), which were double-blind and parallel in design, with at least 30 participants were included.

Specific interventions included in the review

Glucosamine (400 mg intramuscular twice weekly for 6 weeks) or gluscosamine sulfate (250 mg capsules; 2 capsules taken three times daily before meals for up to 8 weeks), versus placebo (lactose capsules or sodium chloride) or ibuprofen (200 mg tablets; 2 tablets taken three times a day before meals).

Participants included in the review

Patients with either osteoarthritis of the knee, established osteoarthritis, or unilateral osteoarthritis. Only one study listed participants as aged at least 18 years.

Outcomes assessed in the review

The outcomes assessed were:

a change in the Lequesne severity index or a change in articular pain;

joint tenderness and swelling; and

restriction of active and passive movement, rated on a scale of zero to 4 before treatment and after 7, 14, 21 and 30 days of therapy; or

changes in articular pain, rated on a scale of zero to 3 before treatment and after 1, 2, 4 and 8 weeks of treatment.

How were decisions on the relevance of primary studies made?

The authors do not state how the papers were selected for the review, or how many of the authors performed the selection.

The authors do not state that they assessed quality.

The authors do not state how the data were extracted for the review, or how many of the authors performed the data extraction.

How were the studies combined?

The authors discussed the included trials in a narrative review with no statistical pooling of the data. The narrative review presented the details, results and observed deficiencies for each individual trial.

How were differences between studies investigated?

The authors do not state how differences between the studies were investigated.

Three RCTs with 275 participants (137 in the glucosamine group, 136 in the control group, and 2 participants unaccounted for) met the inclusion criteria for the efficacy review. Four studies (3 RCTs and 1 uncontrolled study) were used to extract the data for adverse effects.

The adverse effects from glucosamine appeared to be minimal and mainly consisted of minor gastrointestinal problems.

Each of the 3 critically evaluated studies reported a decrease in the symptoms of osteoarthritis (e.g. decreased Lequesne index, decreased pain severity, increased range of motion) for the glucosamine group, which was greater than that obtained in the control group.

The cost of a 30-day supply of glucosamine sulfate was approximately $35 to $45 for the 500 mg capsules, and approximately $30 to $40 for the 1,000 mg capsules. The prices varied according to the manufacturer, added ingredients, and the place of purchase.

Glucosamine may have a role in the management of osteoarthritis; however, its use cannot be recommended, based on the available scientific literature.

The authors clearly stated the research question and the inclusion criteria for the review. They conducted a limited review of the literature, and although it is unlikely that additional studies have been missed, they did not address issues of bias by searching for unpublished or non-English studies.

The primary trials were tabulated and the content of each of the individual trials was discussed in detail in the text of the review. The quality of the included trials was not assessed or scored, and it was not reported how judgements about the inclusion of studies were made. The criteria and methods used to extract the data were also not stated.

Pending additional research, the results should be viewed with caution since the results of the trials could only be pooled in a narrative review, without statistical analysis or measurement of the heterogeneity between the studies. In addition, the authors agreed that there were flaws in the original study designs.

Practice: The authors state that patients should be advised that although glucosamine may possibly improve the symptoms of osteoarthritis, claims of chondroprotection have not been substantiated.

Research: The authors state that further research is needed to assess long-term safety and to provide conclusive evidence for the effectiveness of glucosamine.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.