Convert any Theophylline Level result between units on the unit converter.
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.
A commonly taught critical (panic) value is > 20 µg/mL (nausea, tachycardia, seizures). Critical results are reported to the provider immediately under your facility's policy.
Source: Adult reference values compiled from Pagana & Pagana, Mosby's Diagnostic and Laboratory Test Reference, and Fischbach & Dunning, A Manual of Laboratory and Diagnostic Tests. Reference ranges vary by laboratory, method, age, sex, and population — always use the range printed on the actual result.
Above the range
Common causes of a high Theophylline Level
Excess dosing
Liver disease
Heart failure
Interactions (cimetidine, ciprofloxacin)
Below the range
Common causes of a low Theophylline Level
Smoking (increases clearance)
Nonadherence
At the bedside
Nursing considerations
Watch for tachyarrhythmias, nausea, and seizures as levels rise; narrow therapeutic window.