Boothe D M, Simpson G, Foster T
Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, Texas A&M University, College Station 77843-4466, USA.
Am J Vet Res. 1996 Sep;57(9):1299-303.
To characterize the effects of serum separation tubes (SST) on serum drug concentrations.
Clinically normal dogs (clorazepate, n = 7) or dogs with epilepsy (phenobarbital, n = 7) were studied in experiment 1, and samples submitted for therapeutic drug monitoring (n = 87) were studied in experiment 2.
In experiment 1, blood containing either drug was placed in 2 types of 4-ml SST (SST-A and SST-B) and in nonserum separation tubes (non-SST [control]). Samples were processed, then stored at 20 to 22 C (both drugs) or 10 C (phenobarbital only). Aliquots were collected for 96 hours. The rate constant of disappearance and the percentage decrease of each drug over time were determined for each tube. For experiment 2, paired samples were collected in non-SST and SST and submitted by mail for therapeutic drug monitoring. The SST samples were either decanted from SST prior to shipment (group 1; n = 30) or mailed in SST with serum in contact with the silica gel (group 2; n = 57). Drug concentrations and drug elimination half-life were compared between groups. For both experiments, drugs were detected in samples, using polarized immunofluorescence.
For experiment 1, the rate constant of drug disappearance for both drugs was greater in the 4-ml SST-A (P < 0.0001). This SST also caused the greatest percentage decrease (20% for phenobarbital and 35% for benzodiazepines) at 96 hours. Refrigeration reduced the mean decrease in phenobarbital at 96 hours to 11%. For experiment 2, phenobarbital concentration was lower for both SST, compared with non-SST (P < 0.0005). Phenobabital had decreased a mean 6.4 +/- 0.5% in group-1 and a mean 30.5 +/- 11.1% in group-2 (P < 0.0005) samples.
The SST should be avoided when collecting serum for monitoring of either phenobarbital or benzodiazepines.
The SST can falsely decrease serum drug concentrations and should be avoided when collecting blood for therapeutic drug monitoring.
描述血清分离管（SST）对血清药物浓度的影响。
实验1中研究了临床正常犬（氯氮卓，n = 7）或患有癫痫的犬（苯巴比妥，n = 7），实验2中研究了提交进行治疗药物监测的样本（n = 87）。
在实验1中，将含有任一药物的血液置于两种4毫升的SST（SST - A和SST - B）以及非血清分离管（非SST[对照]）中。对样本进行处理，然后在20至22℃（两种药物）或10℃（仅苯巴比妥）下储存。在96小时内收集等分试样。测定每个试管中每种药物随时间的消失速率常数和减少百分比。对于实验2，在非SST和SST中收集配对样本，并通过邮寄提交进行治疗药物监测。SST样本要么在装运前从SST中倒出（第1组；n = 30），要么装在SST中邮寄，血清与硅胶接触（第2组；n = 57）。比较两组之间的药物浓度和药物消除半衰期。对于两个实验，使用偏振免疫荧光法在样本中检测药物。
对于实验1，两种药物在4毫升SST - A中的药物消失速率常数更大（P < 0.0001）。该SST在96小时时也导致最大的减少百分比（苯巴比妥为20%，苯二氮卓类为35%）。冷藏将苯巴比妥在96小时时的平均减少量降至11%。对于实验2，与非SST相比，两种SST中的苯巴比妥浓度均较低（P < 0.0005）。在第1组样本中苯巴比妥平均降低了6.4±0.5%，在第2组样本中平均降低了30.5±11.1%（P < 0.0005）。
在收集用于监测苯巴比妥或苯二氮卓类药物的血清时应避免使用SST。
SST可错误地降低血清药物浓度，在采集血液进行治疗药物监测时应避免使用。
