GlaxoSmithKline (GSK) has recently issued a Dear Healthcare Professional letter to notify healthcare professionals of new safety information regarding products containing rosiglitazone.

Rosiglitazone is a thiazolidinedione antidiabetic agent used as an adjunct to diet and exercise in the management of type II diabetes mellitus. It is available as Avandia® (rosiglitazone) and Avandamet® (rosiglitazone and metformin).

GSK has received very rare post-marketing reports in other countries of new onset and worsening macular oedema in patients receiving rosiglitazone. In the majority of these cases, the patients also reported concurrent peripheral oedema. In some cases, the macular oedema resolved or improved following discontinuation of therapy and in one case, macular oedema resolved after dose reduction.

According to the Dear Healthcare Professional Letter issued by GSK, macular oedema is known to occur in association with diabetic retinopathy, especially when this condition progresses. Risk factors for macular oedema include duration of diabetes, presence of retinopathy, hypertension, and poor glycaemic control. Patients with macular oedema may complain of blurred or distorted vision, decreased colour sensitivity, and decreased dark adaptation.

HSA has not received any local reports of macular oedema associated with rosiglitazone. Physicians are encouraged to report any suspected adverse drug reactions to the Pharmacovigilance Unit of the HSA.