Test ID: P_PB
Phenytoin, Total and Phenobarbital Group, Serum
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
See individual test descriptions for:
-PNY/8604 Phenytoin, Total, Serum
-PBAR/8252 Phenobarbital, Serum
Profile Information A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| PNY | Phenytoin, Total, S | Yes | Yes |
| PBAR | Phenobarbital, S | Yes | Yes |
Method Name A short description of the method used to perform the test
Immunoassay
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Dilantin (Do Phenytoin, Total unless Free specified)
Dilantin (Phenytoin)
Dilantin + Phenobarb ORDER 8643
Diphenylhydantoin
Diphenylhydantoin + Phenobarb ORDER 8643
DPH
Luminal (Phenobarbital)
PBR
Phenobarb + Mephobarbital ORDER 8637
Phenobarb + Phenytoin Total ORDER 8643
Phenobarb + Primidone ORDER 8621
Phenobarbital
Phenytoin (Dilantin)
Phenytoin Total + Phenobarb 8643
Phenytoin Total + Phenobarb ORDER 8643
Phenytoin, Free and Total ORDER 9993
Phenytoin, Total and Free ORDER 9993
Solfoton (Phenobarbital)
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube: Red top
Specimen Volume: 1 mL
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross reject |
| Lipemia | Mild OK; Gross reject |
| Icterus | Mild OK; Gross OK |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum Red | Refrigerated (preferred) | 14 days |
| Ambient | 14 days | |
| Frozen | 14 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
See individual test descriptions for:
-PNY/8604 Phenytoin, Total, Serum
-PBAR/8252 Phenobarbital, Serum
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
PHENYTOIN, TOTAL
Therapeutic concentration: 10.0-20.0 mcg/mL
Toxic concentration: > or =30.0 mcg/mL
PHENOBARBITAL
Therapeutic concentration
Infants and children: 15.0-30.0 mcg/mL
Adults: 20.0-40.0 mcg/mL
Toxic concentration: > or =60.0 mcg/mL
Interpretation Provides information to assist in interpretation of the test results
See individual test descriptions for:
-PNY/8604 Phenytoin, Total, Serum
-PBAR/8252 Phenobarbital, Serum
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
See individual test descriptions for:
-PNY/8604 Phenytoin, Total, Serum
-PBAR/8252 Phenobarbital, Serum
Supportive Data
See individual test descriptions for:
-PNY/8604 Phenytoin, Total, Serum
-PBAR/8252 Phenobarbital, Serum
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Phenytoin, Total:
1. Richens A: Clinical pharmacokinetics of phenytoin. Clin Pharmacokinet 1979;4:153-169
2. Moyer TP: Therapeutic drug monitoring. In Tietz Textbook of Clinical Chemistry. Fourth edition. Edited by CA Burtis, ER Ashwood. WB Saunders Company, Philadelphia, 2005, pp 1237-1285
Phenobarbital:
Foero O, Kastrup KW, Nielsen EL, et al: Successful prophylaxis of febrile convulsions with phenobarbital. Epilepsia 1972;13:279-285
Method Description Describes how the test is performed and provides a method-specific reference
Enzyme-multiplied immunoassay technique (EMIT) is performed using the Olympus analyzer. EMIT offers an alternative to the traditional spectroscopic and chromatographic method for quantitating blood concentrations of drugs. The technique for drugs is based upon an enzymatic assay for glucose-6-phosphate dehydrogenase, using spectral properties at 340 nm, in which the reduction of nicotinamide adenine dinucleotide (NAD) substrate is monitored. The basis of the drug detection technique is an immunological reaction between the drug and a specific antibody. The reagent contains the enzyme (glucose-6-phosphate dehydrogenase) to which the drug is covalently bound and antibody-specific to the drug. The antibody binds most of the drug-bound enzyme, rendering the enzyme inactive. This results in a baseline enzymatic activity. In the presence of free drug, antibody equilibrates between free drug and enzyme-bound drug leaving some of the drug-bound enzyme uncomplexed and able to catalyze the reaction. If more free drug is introduced, either as standard or sample, then competition for the antibody takes place between the drug in the sample and the drug attached to the enzyme. This results in more drug-bound enzyme being left uncomplexed and able to catalyze the enzyme reaction at a greater rate as compared to the baseline activity. The observed enzyme activity increases with the amount of total free drug in the sample.(Package inserts: EMIT 2000 Phenytoin Assay and EMIT 2000 Phenobarbital Assay. Olympus, Melville, NY. October 2005)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Sunday; Varies
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
80184-Phenobarbital
80185-Phenytoin, total
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| 8252 | Phenobarbital, S | 3948-7 |
| 8604 | Phenytoin, Total, S | 3968-5 |
External
link
PDF
document
Excel
document
Word
document