Objective: The purpose of this review was to identify which descriptors of body size are most appropriate for the dosing of emergency cardiovascular medications in obese patients. Dosing recommendations are frequently assumed to mean total body weight in kg, unless otherwise stated. Other descriptors of body weight may be more appropriate for determining dosing requirements in obese patients based on the physiological changes associated with obesity.
Materials and Methods: An extensive review of the literature was conducted to identify studies examining the relationship between size descriptors, pharmacokinetic measures, and emergency medications which are dosed according to weight. Size descriptors examined were total body weight, adjusted body weight, ideal body weight, and lean body mass. Pharmacokinetic measures included volume of distribution and clearance. The drugs selected for review were the weight-based emergency medications recommended in the American Heart Association guidelines for advanced cardiac life support.
Results: There is limited research regarding the dosing of emergency medications in obese patients. A review of available research indicates that dosing according to general drug properties, such as lipophilicity or hydrophilicity, in correlation with different body descriptors, produced inconsistent results. Caution when administering procainamide is indicated, based on the available research.
Conclusion: Currently there are no reliable rules for weight-based dosing of emergency medications in obese patients. Dosing should be based on different body descriptors specific to individual drugs rather than general drug properties or classifications. Further research is needed. Patients should be closely monitored for desired effects and drug toxicity following the administration of weight-based emergency medications.
