FDA Internal Review To Evaluate Potential Symlin Dosing Confusion
This article was originally published in The Pink Sheet Daily
Executive Summary
Agency evaluation follows a medication safety alert for the adjunctive diabetes therapy issued by the Institute for Safe Medication Practices. Watchdog group cites confusion in dosage instructions that could result in overdose/underdose of Symlin.
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FDA is beginning an internal review of the dosage instructions for Amylin's diabetes agent Symlin to determine if modifications are needed to limit patient and practitioner confusion, the agency said. FDA's internal review comes after a medication safety alert was issued for Symlin (pramlintide) by the Institute for Safe Medication Practices June 16. According to the alert, the current recommended method for measuring doses of Symlin could result in an overdose that "is likely to cause serious harm, perhaps even death." ISMP's concern is based on potential confusion between the manufacturer's recommended microgram dosing schedule and the unit dosing used on insulin syringes. "Users who require a 30 mcg dose, for instance, would withdraw Symlin to the 5 unit level of an insulin syringe. But, despite education, it's predictable that a patient or practitioner will use an insulin syringe and withdraw 30 units when 30 mcg is intended," the alert states. The current dosing format also has the potential to result in under-dosing, the watchdog group warned. Additionally, the dosing chart in the patient medication guide for Symlin lists only the "dosage prescribed" and the "increment using a U-100 syringe," not "volume," ISMP said. "This could lead to errors if prescribers recognize that Symlin doses can be measured in a tuberculin syringe and subsequently order these syringes to reduce confusion with the patient's insulin syringes," the group states. The ISMP alert also cites a risk of confusion with insulin products, the use of "dangerous" abbreviations and dose designations in packaging, and the dosing chart among its safety concerns. For example "µg" could be misinterpreted as a "u" for units, a more familiar diabetic term, the alert notes. ISMP notified Amylin of its concerns and recommended the company change the dosing expression used in the package insert, medication guide and vial label for Symlin to micrograms rather than µg. The group also suggested Amylin make Symlin available in its own delivery device, "such as a pen injector that is capable of delivering 15 to 120 mcg per dose with 15 mcg dosing increments." Another alternative would be to make Symlin less concentrated to allow for easier use of tuberculin syringes, ISMP said. FDA approved Symlin as an adjunct therapy for type 1 and type 2 diabetes in March (1 (Also see "Amylin’s Symlin Diabetes Therapy Gets FDA Nod" - Pink Sheet, 16 Mar, 2005.)). - Jessica Merrill |