Test Code THEO Theophyllin
Specimen and Container/Tube
Specimen Type: Serum
Preferred Specimen: Red Top
Other Acceptable specimens: Plasma/Li or Sodium-Heparin Dark Green Top (No Gel Separator),Plasma/Lavendar K2 Top
Specimen Stability
Storage Temperature |
Stability |
Room temperature |
Not acceptable |
Refrigerated |
7 days |
Frozen |
60 days |
Collection Instructions
Collect specimen per standard laboratory collection procedures. Specimens representing the trough level should be collected just before the next scheduled dose at steady state.
Specimen Handling and Transport Instructions
UCMC Onsite Instructions:
- Collect specimen per standard collection procedure and send to laboratory immediately. Specimens representing the trough level should be collected just before the next scheduled dose at steady state.
UCMC Offsite and UC MedLab Outreach Instructions:
- Specimens representing the trough level should be collected just before the next scheduled dose at steady state.
- Samples should be centrifuged within 2 hours of collection.
- Centrifuge specimens at >2500 x g for 10 minutes at room temperature.
- Aliquot sample into plastic transport tube containing a minimum of 0.2 mL of specimen.
- Samples must be sent refrigerated at 2-8oC.
Rejection Criteria
- Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits.
- Specimens that are clotted or grossly hemolyzed.
- Specimens that were transported unspun/whole blood and draw time is greater than 6 hours.
Reference Values
Test |
Age |
Sex |
Reference Range |
Theophylline |
All |
All |
10 - 20 μg/mL |
Critical Values
Analyte |
Unit |
Low |
High |
Age |
Theophylline |
μg/mL |
N/A |
> 25 |
All |
Turnaround Time
Turnaround times are relative to the time the specimen is received in the test laboratory.
STAT Turnaround Time: 1 hour
Routine Turnaround Time: 4 hours
Testing Schedule: 24/7
Clinical Indications
- Monitoring of theophylline concentrations in serum is useful, since rates of individual theophylline clearance can vary and severe toxicity has been observed without prior occurrence of minor side effects.
Test Components
Theophylline
Methodology
Kinetic Interaction of Microparticles in solution (KIMS) (Roche Diagnostics)
CPT Codes
80198
LOINC Codes
4049-3
Synonyms/Keyword Search
Theo-24, Elixophylline, Theochron
Additional Information
- Results should always be assessed in conjunction with patient's medical history, clinical examination and other findings.
- Some therapeutic drug concentrations are reduced when the sample is stored in a seperator tube for a prolonged period of time (>2 hours).
Last Review Date
1/26/2023
Volume
Preferred Volume: 0.5 mL
Minimum Volume: 0.2 mL