Intravenous Aminophylline (Adults)
Theophylline is a bronchial smooth muscle relaxant and bronchodilator. Intravenous (IV) theophylline is only
available as aminophylline, which is a pro-drug of theophylline.
Indication Intravenous Aminophylline may be used for ACUTE exacerbation of Chronic Obstructive Lung
Disease (COPD) - to be used as an adjunct to the management of exacerbations of COPD if there
is an inadequate response to nebulised bronchodilators.
Before using intravenous aminophylline for an exacerbation of COPD please consider
whether patient may be a suitable for Non Invasive Ventilation. (For example patients with
hypercapnic respiratory failure and a pH <7.35)
Please discuss use of intravenous aminophylline with a SpR or Consultant as potential side
effects may outweigh benefits and evidence of benefit in COPD is weak. Significant side effects
include arrhythmias and we would recommend avoiding its use in patients with any significant
arrhythmia such as Atrial Fibrillation.
The loading dose is given only if life threatening features are present and if the patient is
NOT already taking oral theophyllines.
IV Aminophylline should be the first line IV therapy in patients with COPD, whereas IV
aminophylline or IV salbutamol can be used for patients with asthma if they are not responding to
standard treatment.
We would recommend all patients with acute asthma who are ill enough to need aminophylline IV
are discussed with a SpR or consultant
Check the
drug
history
If the patient usually takes maintenance aminophylline or theophylline therapy, check the
theophylline serum level on admission and omit the loading dose.
For obese
patients
use IBW
for dosing
IBW = Ideal body weight
IBW (kg) for men = [(height (cm) – 154) x 0.9 ] + 50
IBW (kg) for women = [(height (cm) – 154) x 0.9 ] + 45.5
Loading
dose 5mg / kg aminophylline IV (max 500mg)- Write “LOADING DOSE” on the prescription
Add dose to 100mL of a compatible infusion fluid
Administer using a rate controlled infusion pump over 20 minutes
Monitoring
during the
bolus dose
If a patient experiences acute adverse effects i.e. palpitations, tachycardia, hypotension,
whilst the loading dose is being infused, the infusion may be stopped for 5-10 minutes or
administered at a slower rate. Ideally the patient should be cardiac monitored during the
loading dose for these reasons
Maintenance
dose 500 micrograms / kg / hour ( Elderly: 300 micrograms / kg / hour)
Add 500mg to 500mL or 250mg to 250mL of a compatible infusion fluid (1mg/mL).
Administer using a rate controlled infusion pump.
Prescribe as mg / hour NOT mL / hour
Maximum
concentration 25mg in 1ml Maximum rate of
administration 25mg per minute
Compatible infusion fluids Sodium chloride 0.9% or glucose 5%
Adverse
effects Arrhythmias, hypotension, tachycardia & convulsions. Signs of toxicity: nausea, palpitations,
twitching and convulsions (see BNF for full list of adverse effects)
Monitoring Heart rate and blood pressure monitoring should be recorded every hour for the first four hours
and then every two hours if stable
Management
and dose
reduction
Aminophylline infusions should be continued for at least 24 hours with review by medical staff at
agreed intervals, and may be continued for a further 24-48 hours. Tachyarrhythmias tend to be
the main reason for early discontinuation and therefore monitoring of potassium is essential. The
aim is to reduce the infusion over a 10-12 hour period of time once stable.
It is recommended that dose reduction begin in the morning, aiming to stop the infusion by mid to
late afternoon. This allows oral theophyllines (if appropriate) to be given that evening. The infusion
rate should be reduced every 2 hours with a medical review late in the afternoon prior to stopping
