Clinical Use: Trough or 2-4 hours post dose (consistent)
Background: Theophylline is a drug used for treating asthma by relaxing bronchial smooth muscle and lessening the chance of bronchospasm. Theophylline can also be administered to decrease chances of apnoea in premature babies. The drug is rapidly, consistently and completely absorbed and transformed by the liver into relatively inactive metabolites that are excreted in the urine. As the rate of hepatic biotransformation is dependent on age, diet, illness and the symptoms of toxicity unreliable, then determination of the serum levels is important as part of a TDM programme for the individual. Theophylline measurements are used in the diagnosis and treatment of theophylline overdose and in monitoring its levels in patients to ensure appropriate therapy.
Reference Ranges: Therapeutic Range: 10 – 20 mg/L
Associated Diseases:
Patient Preparation:
Specimen Requirements: Sample type:

  • Serum and Plasma (Lithium Heparin)

Sample identification:

  • Three patient identifiers from
    • Name
    • D.O.B.
    • Address
    • N.H.S. number
    • Unit Number

    should match on the specimen and request form. This check may be performed prior to centrifugation by the Central Sort department.

Turnaround Time: 4 weeks
Additional Information:
Referred Test: