Biomaterial Database

Effects of serum separation tubes on serum benzodiazepine and phenobarbital concentrations in clinically normal and epileptic dogs. 1996

D M Boothe, and G Simpson, and T Foster

Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, Texas A&M University, College Station 77843-4466, USA.

OBJECTIVE To characterize the effects of serum separation tubes (SST) on serum drug concentrations. METHODS 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. METHODS 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. RESULTS 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. CONCLUSIONS The SST should be avoided when collecting serum for monitoring of either phenobarbital or benzodiazepines. CONCLUSIONS The SST can falsely decrease serum drug concentrations and should be avoided when collecting blood for therapeutic drug monitoring.

UI	MeSH Term	Description	Entries
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D001800	Blood Specimen Collection	The taking of a blood sample to determine its character as a whole, to identify levels of its component cells, chemicals, gases, or other constituents, to perform pathological examination, etc.	Blood Specimen Collections,Collection, Blood Specimen,Collections, Blood Specimen,Specimen Collection, Blood,Specimen Collections, Blood
D004283	Dog Diseases	Diseases of the domestic dog (Canis familiaris). This term does not include diseases of wild dogs, WOLVES; FOXES; and other Canidae for which the heading CARNIVORA is used.	Canine Diseases,Canine Disease,Disease, Canine,Disease, Dog,Diseases, Canine,Diseases, Dog,Dog Disease
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004827	Epilepsy	A disorder characterized by recurrent episodes of paroxysmal brain dysfunction due to a sudden, disorderly, and excessive neuronal discharge. Epilepsy classification systems are generally based upon: (1) clinical features of the seizure episodes (e.g., motor seizure), (2) etiology (e.g., post-traumatic), (3) anatomic site of seizure origin (e.g., frontal lobe seizure), (4) tendency to spread to other structures in the brain, and (5) temporal patterns (e.g., nocturnal epilepsy). (From Adams et al., Principles of Neurology, 6th ed, p313)	Aura,Awakening Epilepsy,Seizure Disorder,Epilepsy, Cryptogenic,Auras,Cryptogenic Epilepsies,Cryptogenic Epilepsy,Epilepsies,Epilepsies, Cryptogenic,Epilepsy, Awakening,Seizure Disorders
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000927	Anticonvulsants	Drugs used to prevent SEIZURES or reduce their severity.	Anticonvulsant,Anticonvulsant Drug,Anticonvulsive Agent,Anticonvulsive Drug,Antiepileptic,Antiepileptic Agent,Antiepileptic Agents,Antiepileptic Drug,Anticonvulsant Drugs,Anticonvulsive Agents,Anticonvulsive Drugs,Antiepileptic Drugs,Antiepileptics,Agent, Anticonvulsive,Agent, Antiepileptic,Agents, Anticonvulsive,Agents, Antiepileptic,Drug, Anticonvulsant,Drug, Anticonvulsive,Drug, Antiepileptic,Drugs, Anticonvulsant,Drugs, Anticonvulsive,Drugs, Antiepileptic
D001569	Benzodiazepines	A group of two-ring heterocyclic compounds consisting of a benzene ring fused to a diazepine ring.	Benzodiazepine,Benzodiazepine Compounds
D016903	Drug Monitoring	The process of observing, recording, or detecting the effects of a chemical substance administered to an individual therapeutically or diagnostically.	Monitoring, Drug,Therapeutic Drug Monitoring,Drug Monitoring, Therapeutic,Monitoring, Therapeutic Drug