Pathology Handbook



Aminophylline, Nuelin

Clinical Indications

Theophylline levels are required if i.v. aminophylline is being considered for patients already taking oral theophylline preparations, as serious toxic side effects may occur. Measurement of theophylline levels may be helpful if no clinical improvement is seen on increasing doses, in confirming toxicity and management of the overdosed patient and in patients where compliance may be an issue.

Request Form

Request on ICE


Analysed if specific criteria met.
In management of theophylline overdose, levels may be measured urgently under the following circumstances (please contact Clinical Biochemistry)
(a) if there is doubt about the clinical severity of poisoning 
(b) in all patients with severity grades 3 and 4.

Specific Criteria

Patient on i.v theophylline(aminophylline) or on ITU/HDU
Requested by Consultant Physician for patients on oral theophylline where compliance may be an issue or if agreed with Consultant Biochemist
Management of theophylline overdose (see above)

Patient Preparation

Samples should preferably be collected pre-dose.

Turnaround Time



Serum in yellow top (SST) tube


2 ml


Vacutainer gold top

Causes for Rejection

Not meeting specific criteria for analysis.

Reference Range

Therapeutic range: 10 -20 mg/L


Healthy adults: 3 - 13 hours (reduced in smokers)