Availability of Information for Dosing Injectable Medications in Underweight and Obese Patients

Abstract

OBJECTIVES: To evaluate the product information and pivotal studies of injectable medications to determine if a specific size descriptor was included and if information was provided for dosing patients with extremes of body weight (body mass index < 18.5 or > 40 kg/m2). METHODS: This is a descriptive study of medications that received an approved new drug application (NDA) by the FDA between 1 January 2004 and 30 January 2009. Any information related to size descriptors, or dosing of patients with extremes of weight, was extracted and evaluated with a dosing usefulness score that ranged from a low of 0 to a high of 3. A score of 2 or greater was considered at least minimally adequate for dosing patients with extremes of weight. RESULTS: Of the 84 medications evaluated, some reference to weight descriptors was found for 23 (27%). None of the medications had information that generated a usefulness score of 2 or greater. CONCLUSIONS: The product information and pivotal studies involving newly approved medications is inadequate for dosing patients with extremes of weight and further research is needed. The FDA should mandate that product information contain the size descriptor and extremes of body weight relative to age and height that were used to develop dosing recommendations.