Download Preparation : Vials contain 250mg aminophylline in 10mL

Dosing Information for Intravenous (IV) Aminophylline
in Adults
Preparation: Vials contain 250mg aminophylline in 10mL
**PATIENTS ALREADY TAKING ORAL AMINOPHYLLINE/THEOPHYLLINE SHOULD NOT
RECEIVE A LOADING DOSE OF IV AMINOPHYLLINE**
Contraindications
 Hypersensitivity to aminophylline, ethylenediamine or those allergic to theophyllines, caffeine
or theobromine.
 Acute porphyria.
 Aminophylline should not be administered concomitantly with other
aminophylline/theophylline preparations.
Loading dose 5mg/kg to a maximum of 500mg based on ideal bodyweight(1,2).
Loading dose aminophylline infusion
Dilute required dose in 100mL of sodium chloride 0.9% or glucose 5%.
Maximum concentration 25mg/mL. Administer by intravenous infusion over
20-30 minutes using an infusion pump.
Maximum rate not to exceed 25mg/min.
Requires ECG and BP monitoring.
Note: Loading dose must be given with a doctor present.
How do I administer a
loading dose infusion
of aminophylline?*
*Refer
to Trust IV guide for further details
Maintenance dose for aminophylline
500 micrograms/kg/hr based on ideal body weight (2)
Dose may be lower in patients with heart failure, hepatic disease and in the elderly.
Consider:
Elderly or cor pulmonale a dose of 300 micrograms/kg/hr.
Congestive heart failure or liver impairment a dose of 100-200 micrograms/kg/hr.
Dilute 1mg aminophylline in 1mL (i.e. 500mg in 500mL) with sodium chloride
How do I administer 0.9% or glucose 5%* and administer by intravenous infusion over 24 hours
an intravenous
using an infusion pump. Maximum concentration 25mg/mL. Maximum rate
maintenance dose should not exceed 25mg/min.
of aminophylline?
Requires ECG and BP monitoring.
*
Refer to Trust IV guide for further details
Aminophylline Monitoring and Adverse Effects
 Requires ECG, blood pressure and electrolyte monitoring.
 Therapeutic drug level monitoring required to prevent toxicity (see below).
 Rapid administration may cause hypotension, headache, anxiety, arrhythmias, insomnia and
convulsions.
 Other possibly adverse effects – hypersensitivity reactions, rash, erythema, pruritis and
tachycardia.
 Monitor for extravasation – extreme pH (8.6-9). Extravasation very likely to cause tissue
damage.
Therapeutic Drug Monitoring
Refer to Guidelines for the Management of Common Medical Emergencies and the Use of Antimicrobial Drugs, current edition for further details.
Target aminophylline level is 10 – 20mg/L
Sampling Time
Monitor at 4 – 6 hours post loading dose then at 24 hourly intervals during IV
infusion or after 5 days following initiation of oral aminophylline/theophylline
to prevent toxicity.
Time to steady state 2 days (following infusion where loading dose has not been given), 3 days
(following oral loading).
(1) Trust guidance
(2) BNF 62 September 2011
December 2011
Interactions See BNF for full details
Aminophylline/ theophylline can interact with many drugs. All concurrent medications should be
assessed for potential interactions before aminophylline/theophylline is initiated. Some clinically
important interactions include:
Drugs/substances that increase
Drugs/substances that decrease
aminophylline/theophylline concentrations
aminophylline/theophylline levels leading to sub
leading to toxicity
therapeutic levels
Antiepileptics e.g. carbamazepine,
Antibacterials e.g. azithromycin
phenobarbitone
Antifungals e.g. fluconazole
Smoking
Antivirals e.g. aciclovir
Calcium-channel blockers e.g. verapamil
Oestrogens
Interferons
Converting IV aminophylline to oral aminophylline
1. Convert the hourly rate to the total amount administered in 24 hours by multiplying the hourly
dose by 24.
2. Divide this total amount by the dosing interval for oral administration, e.g. 2 for twice a day. It is
assumed that the oral product is completely absorbed, i.e. the bioavailability is 100%.
For example:
If the IV aminophylline dose is 35mg /hr and the dosing interval for oral aminophylline is every 12 hours, i.e. twice a day,
divide the total daily dose 840mg by 2. This gives the equivalent oral dose to be 420mg twice a day.
35mg x 24 = 420mg
2
A suitable aminophylline dosing regimen could be Phyllocontin Continus ® 225mg, 450mg (2x225mg tablets) twice a day.
Converting IV aminophylline to oral theophylline
Convert the hourly rate to the total amount administered in 24 hours by multiplying the hourly dose
by 24.
In order to calculate the equivalent theophylline dose, multiply this total aminophylline dose by 0.8,
which is the salt correction factor. It is assumed that the oral product is completely absorbed.
For example
If the IV aminophylline dose is 35mg/hr, then the total daily dose is 840mg. The oral theophylline dose is 840mg x 0.8 =
672mg daily
A suitable theophylline dosing regimen could be Uniphyllin Continus®, 300mg in the morning and 400mg in the evening.
Oral aminophylline and theophylline modified release preparations available
Brand
Phyllocontin Continus®
Brand
Nuelin SA®
Slo-Phyllin®
Uniphyllin Continus®
Aminophylline
Available strengths
225mg
Theophylline
Available strengths
175mg
60mg, 125mg, 250mg
200mg, 300mg, 400mg
Dosing frequency
Twice daily
Dosing frequency
Twice daily
Twice daily
Twice daily
December 2011