Hypersensitive adverse drug reactions to glucosamine and chondroitin preparations in Australia between 2000 and 2011

Purpose of the study This study investigates spontaneous adverse drug reactions (ADRs) to glucosamine and chondroitin in the Australian population between 2000 and 2011, with a primary focus on hypersensitivity reactions. Study design Case reports of ADR to glucosamine and chondroitin sent to the Therapeutic Goods Administration between 2000 and 2011 were obtained and analysed. The demographic information and severity of the ADR were recorded for individual ADR cases. These reactions were classified according to the Brown et al grading system for generalised hypersensitivity reactions. This included mild hypersensitivity reactions (generalised erythema, urticaria and angioedema) through to moderate hypersensitivity reactions (wheeze, nausea, vomiting, dizziness (presyncope), diaphoresis, chest or throat tightness and abdominal pain), and more severe reactions (hypotension, confusion and collapse). Results In this study of 366 ADRs to glucosamine and chondroitin preparations, 71.85% of cases (n=263) were found to have hypersensitivity reactions. Of these 263 cases, 92 cases were classified as mild (eg, pruritus, urticaria and lip oedema), 128 cases classified as moderate (such as dyspnoea, nausea and abdominal pain), and 43 cases classified as severe (including amnesia, gait disturbance, somnolence and hypotension). It is not clear whether the patients involved had a known shellfish allergy or underlying atopy. Conclusion Results of this investigation support the need for clear labelling on glucosamine and chondroitin preparations to raise awareness of possible adverse events for those predisposed to allergy or atopy in response to shellfish.