Theophylline

Test Code

THEO (NI)

Quest Code

878

CPT Codes
80198

Preferred Specimen

1 mL serum collected in a red-top tube (no gel)

Patient Preparation
Collect as a trough just prior to next dose

Minimum Volume

0.2 mL

Other Acceptable Specimens

Plasma collected in: Sodium heparin (green-top) tube, lithium heparin (green-top) tube, or EDTA (lavender-top) tube

Transport Container

Transport tube

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 6 days
Refrigerated: 7 days
Frozen: 90 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Serum separator tube (SST)

Methodology
Immunoassay (IA)

Setup Schedule

Mon-sat

Report Available

1-3 days

Reference Range

≤5 Months	5.0-10.0 mg/L
>5 Months	10.0-20.0 mg/L

Clinical Significance

Theophylline is used in the treatment of bronchial asthma as well as in the treatment of chronic obstructive pulmonary disease and episodes of prolonged apnea in pre-term infants. Theophylline levels are monitored to assure adequate therapeutic levels are achieved and to avoid toxicity.

Performing Laboratory

Quest Diagnostics-Lenexa

10101 Renner Blvd

Lenexa , KS 66219-9752

Last Updated: July 22, 2025

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.