Below the range
Common causes of a low Theophylline Level
- Smoking (increases clearance)
- Nonadherence
Looking for the other direction? See what causes a high Theophylline Level.
All tests · Therapeutic Drug Levels · Theophylline Level
Below the range
What causes a low Theophylline Level?
Normal range 10-20 µg/mL (56-111 µmol/L SI). Specimen: Serum. See the full Theophylline Level reference page for critical values and nursing considerations.
What is the normal range for Theophylline Level?
The standard teaching reference range for Theophylline Level is 10-20 µg/mL in conventional units, or 56-111 µmol/L in SI units. This value is measured in serum.
| Specimen | Serum |
|---|---|
| Conventional range | 10-20 µg/mL |
| SI range | 56-111 µmol/L |
| Critical value | > 20 µg/mL (nausea, tachycardia, seizures) |
| Panel | Therapeutic Drug Levels |
Full details, including nursing considerations, on the Theophylline Level normal range page. Reference ranges vary by laboratory, method, age, sex, and population - always use the range printed on the actual result.
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