Please note the dosage and dose time on the request slip to allow interpretation of results.
GENERAL NOTES
APPLICATION: Monitoring theophyline therapy in asthmatics.
INTERPRETATION: During acute illness, the half-life may be prolonged beyond the usual range of 3-9 hours; toxicity may develop if the dosage is not reduced. Toxicity may occur within the therapeutic interval in some patients. Cigarette smoking reduces the half-life and therefore decreases levels significantly. The apparent half-life is also prolonged when slow-release preparations are taken. Anti-asthmatic drug. For advice on collection times, contact the Therapeutic Advisory Service (beep 0282).