77.謝先生身高170 cm，體重100 kg，理想體重63 kg，預計30 mg/kg/day，每天分2次給，vancomycin每次劑 量多少最為適當？
(A)1,500 mg
(B)1,000 mg
(C)1,200 mg
(D)945 mg

資料來自UpToDate(符合該病人情況的部分已用螢光筆標示)：

Obese patients — There is no well-validated, universally accepted nomogram to guide the approach to vancomycin dosing in obese patients [10,23-25]. Our approach is as follows:

●Loading dose – The loading dose, if given, is based on actual body weight (up to a single maximum dose of 3 grams) in all patients who are overweight or obese. (See 'Loading dose' above.)

●Initial maintenance dose – For patients with body mass index ≥25 kg/m2 (calculator 2), we calculate an ideal body weight (calculator 3) and, depending on the result, proceed as follows:

•For patients with actual body weight ≤125 percent of ideal body weight, the initial maintenance dose is based on actual body weight, according to the nomogram (table 1).

•For patients with actual body weight is >125 percent of ideal body weight, our approach to determining the initial maintenance dose depends on whether the patient weighs up to 100 kg or more than 100 kg:

-For patients ≤100 kg, the initial maintenance dose is based on a calculated "dosing weight" according to the nomogram (table 1). (Note that the ideal body weight calculator (calculator 3) also calculates the "dosing weight"; refer to the right side of the calculator to locate the dosing weight result.)

-For patients >100 kg, we favor use of individualized dosing regimens based on pharmacokinetic calculations performed by clinical pharmacists. If such services are not available, it is reasonable to use an initial maintenance dose of approximately 30 to 45 mg/kg per day, based on actual body weight, in two or three divided doses for normal renal function [26]. The initial single maintenance dose should not exceed 2 g, irrespective of body weight. Further information on vancomycin dosing in the setting of obesity and renal impairment is included separately in the vancomycin drug information monograph.

Subsequent dose adjustments in obese patients are based on clinical response, kidney function, and serum trough concentration assessments as in nonobese patients [27,28]. (See 'Dose adjustments' above.)

結論：題目問的應該是Initial maintenance dose的部分，應該用實際體重計算，且單一劑量不超過2g。

我在猜想是這樣

1. 用實際體重計算
2. 最大日劑量眾說紛紜，2-3g都有
3. 但不大應該用實際體重就無限上綱劑量，舉本題30 mg/kg/day來說
   若為超重到150 kg，劑量就變成可觀的4.5g
4. 至於上限到底為多少，可能就參考我在8F貼的資訊，
   Clinically, this dose may be capped at a specific weight (eg, 120 kg) or dose (eg, 2500 mg), although this practice has not been prospectively studied.
   

104-1 藥治

4.有關vancomycin用來治療methicillin-resistant Staphylococcus aureus（MRSA）感染之心內膜炎的敘述，下列何者正確？ 
(A)Vancomycin主要依據病人肝功能來調整劑量 
(B)肥胖的病人應該用實際體重計算vancomycin給藥劑量，不受每日最高劑量2g之限制 

what??? 要改成理想劑量嗎？

(C)根據vancomycin谷濃度（trough concentration）調整劑量來確保療效 
(D)Vancomycin谷濃度（trough concentration）須大於25 mg/L 

C

by applied handbook 9th ＱＱ

by applied 11th

若肥胖病人用實際體重給藥，血中濃度會較高...

是要改成調整劑量（ABW）來計算嗎＠＠

求阿摩大神～