ST LOUIS (MD Consult) - On September 15, 2010, the US Food and Drug Administration (FDA) issued a notification that the pediatric dosing recommendations for Valcyte (valganciclovir hydrochloride) oral tablets and oral solution are being updated. The purpose of the FDA action is to help prevent Valcyte overdosing in children.
Valganciclovir is an antiviral medication given to pediatric kidney or heart transplant recipients aged 4 months to 16 years as a means to prevent cytomegalovirus disease.
Under the previous dosing recommendations for Valcyte, pediatric patients with low body weight, low body surface area, and below-normal serum creatinine levels could have a high calculated Schwartz creatinine clearance measurement, resulting in a pediatric dose that approached the adult dose of 900 mg. Patients with these characteristics were not routinely observed in the clinical trials used to derive and confirm the pediatric dose, and they may have been overdosed using the existing dosing algorithm.
The new dosing algorithm specifies that when calculating the pediatric dose, a maximum value of 150 mL/min/1.73 m2 should be used in the formula, even if the calculated Schwartz creatinine clearance result exceeds 150 mL/min/1.73 m2. Furthermore, the updated dosing recommendations state that even if the calculated Valcyte dose exceeds 900 mg, a dose of 900 mg should be administered.
圣路易斯(MD Consult)——2010年9月15日，美国食品药品管理局(FDA)发表一则通告，内容为当局正在更新万赛维(盐酸缬更昔洛韦)片和口服液的小儿用药指南。FDA的此次行动旨在帮助预防儿童中万赛维过量的情况。
缬更昔洛韦是一种抗病毒药，可预防巨细胞病毒感染，用于4个月至16岁的肾或心脏移植受者。
新的剂量计算公式明确指出，当计算小儿剂量时，即使经Schwartz公式计算的肌酐清除率超过150 ml/ (min•1.73 m2) ，公式中也应该使用150 ml/(min•1.73 m2)，即最大值 。另外，更新后的用药指南强调，即使万赛维的剂量计算值超过900 mg，也应按900 mg的剂量给药。
根据以往的万赛维用药指南，低体重、低体表面积和血肌酐水平低于正常值的小儿科患者经Schwartz公式计算的肌酐清除率较高，这导致小儿的用量接近成人用量即900 mg。在推断和证实小儿剂量的临床试验中，未对这些特点的患儿进行常规观察，而采用现有的剂量计算公式可能使他们用药过量。
