Approved by Trust Drug and Therapeutics Committee: March 2021
Review Date: March 2024
INTRAVENOUS AMINOPHYLLINE TREATMENT (DBTH Formulary Guidance)
Therapeutic Range: 55 – 110 µmol/L
Signs of Toxicity:
Nausea, vomiting, diarrhoea, tremor, epigastric pain, headache, insomnia, hypotension, cardiac arrhythmias and convulsions
Plasma Clearance:
Theophylline clearance is reduced in patients with severe congestive heart failure, cor pulmonale, pulmonary oedema, severe liver
disease and hypoxaemic state. The dose may need to be lowered in these patients
Theophylline clearance is increased in smokers
Plasma Theophylline levels may be increased by
- macrolide antibiotics
- calcium channel blockers
- quinolone antibiotics
- cimetidine (see current BNF for complete listing)
Plasma Theophylline levels may be reduced by
- rifampicin
- lithium
- phenytoin
- carbamazepine (see current BNF for complete listing)
Is the patient obese?
Use Actual Weight (Kg)
For all calculations
Use Ideal Body Weight (Kg)
Men: 50 + (2·3) x (Height in inches >5ft)
Women: 45 + (2·3) x (Height in inches >5ft)
For all calculations
No
Yes
Is the patient prescribed oral Theophylline?
e.g. Uniphyllin
No
Yes:
Measure plasma
concentrations
Have they taken a dose in
the last 24 hours?
Give Loading Dose: 5mg/Kg
Add aminophylline loading dose to 100mls
N.Saline 0.9% and infuse over 30 minutes
No
Yes
Omit loading
dose
Give Maintenance Dose: 0.5mg/Kg/Hour
see chart for dose and infusion rates
Take plasma theophylline levels 6 hours after starting
maintenance dose infusion and adjust levels accordingly.
