| Ordering Code | 443 |
|---|---|
| Test Name | Theophylline |
| Alias | THEO Aminophylline Elixophylline Theochron Theo-24 Uniphyl |
| Preferred Specimen | Plasma |
| Preferred Container | Lithium Heparin PST (Green) |
| Other Specimen/Container | Plasma in EDTA, K2 (Lavender), Serum in Plain (Red), Serum in SST (Gold) |
| Optimum Volume | 1 mL |
| Collection Instructions | Pharmacokinetic factors influence the correct time of sample collection after the last drug dose Extended-release tablet: 4-12 hours after administration Recheck levels 1-2 days after any dosage change (adults). |
| Handling Instructions | All specimen types must be centrifuged within 2 hours of collection. If no gel separation present in tube and testing is delayed, plasma/serum is aliquoted from cells within 2 hours of collection Send aliquot if transport time >24 hours. |
| Transport Requirements | Oahu: Refrigerated Airline: Refrigerated (Aliquot) |
| Specimen Stability | Refrigerated: 24 Hours (Centrifuged, unaliquoted gel separator tubes), 1 Month (Aliquot) Frozen: 3 Months (Aliquot) |
| Rejection Criteria | Grossly hemolyzed, Insufficient quantity, Specimen older than stability limits, Uncentrifuged gel separator tube specimens >2 hours old, Unaliquoted gel separator tube specimens >24 hours old |
| Avail. Stat | YES |
| Analytic Time | 1 Day |
| Methodology | Homogenous Enzyme Immunoassay (EMIT) |
Reference range(s)
The reference ranges listed below are valid on this date of March 10, 2026.
| Component | Age | Male Norm | Male Critical Low | Male Critical High | Female Norm | Female Critical High | Female Critical Low | Units | Add'l info |
|---|---|---|---|---|---|---|---|---|---|
| Theophylline | ALL | 10.0-20.0 | >= 20.1 | 10.0-20.0 | >= 20.1 | ug/mL |