Matson Kelly L, Horton Evan R, Capino Amanda C
J Pediatr Pharmacol Ther. 2017 Jan-Feb;22(1):81-83. doi: 10.5863/1551-6776-22.1.81.
Approximately 31.8% of U.S. children ages 2 to 19 years are considered overweight or obese. This creates significant challenges to dosing medications that are primarily weight based (mg/kg) and in predicting pharmacokinetics parameters in pediatric patients. Obese individuals generally have a larger volume of distribution for lipophilic medications. Conversely, the Vd of hydrophilic medications may be increased or decreased due to increased lean body mass, blood volume, and decrease percentage of total body water. They may also experience decreased hepatic clearance secondary to fatty infiltrates of the liver. Hence, obesity may affect loading dose, dosage interval, plasma half-life, and time to reach steady-state concentration for various medications. Weight-based dosing is also a cause for potential medication errors. This position statement of the Pediatric Pharmacy Advocacy Group recommends that weight-based dosing should be used in patients ages < 18 years who are < 40 kg; weight-based dosing should be used in patients ≥ 40 kg, unless, unless the recommended adult dose for the specific indication is exceeded; clinicians should use pharmacokinetic analysis for adjusting medications in overweight/obese children; and research efforts continue to evaluate dosing of medications in obese/overweight children.
在美国，年龄在2至19岁的儿童中，约31.8%被认为超重或肥胖。这给主要基于体重（毫克/千克）给药的药物剂量确定以及预测儿科患者的药代动力学参数带来了重大挑战。肥胖个体通常对亲脂性药物的分布容积更大。相反，由于瘦体重增加、血容量增加以及总体水百分比降低，亲水性药物的分布容积可能增加或减少。他们还可能因肝脏脂肪浸润而导致肝清除率降低。因此，肥胖可能会影响各种药物的负荷剂量、给药间隔、血浆半衰期以及达到稳态浓度的时间。基于体重的给药也是潜在用药错误的一个原因。儿科药学倡导小组的这份立场声明建议，对于体重<40千克且年龄<18岁的患者应采用基于体重的给药；对于体重≥40千克的患者应采用基于体重的给药，除非特定适应证的推荐成人剂量被超过；临床医生应使用药代动力学分析来调整超重/肥胖儿童的用药；并且研究工作应继续评估肥胖/超重儿童的药物剂量。
