7/31/2019 Aminophylline Loading and Maintenance Dose v3
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Aminophylline/Theophylline: Loading and maintenance dose
Prepared by N Fong, ELHT Pharmacy Approved by ELHE Medicines
Management Board
Date: 12/09/2011 V1 Review Date:12/09/2013
Intravenous
(as
Aminophylline)
Note: Aminophylline is the soluble form of theophylline used for
injectable preparations. Doses are calculated based on measured
or
required theophylline serum levels, and therefore dosing needs
to be converted to aminophylline .
Theophylline 1mg is equivalent to Aminophylline 1.25mg for
dosing
Patients NOT already receiving xanthines (theophylline or
aminophylline)
Loading dose: 5mg/kg aminophylline (using ideal body weight)
slow bolus intravenous injection (20-30minutes)
Using 10mg/mL diluted solution centrally or peripherally Using
25mg/mL undiluted solution
centrally for patients with fluid
restriction
Ideal
bodyweight (kg)
Dose (mg) Volume of 10mg/mL
containing required
dose (mL)
Loading dose infusion
rate for 20 minutes
only (mL/hr)
Volume of 25mg/mL
(undiluted)
containing required
dose (mL)
Loading dose infusion
rate for 20 minutes
only (mL/hr)
Centrally only
40 200 20 60 8 24
45 225 22.5 67.5 9 27
50 250 25 75 10 30
55 275 27.5 82.5 11 3360 300 30 90 12 36
65 325 32.5 97.5 13 39
70 350 35 105 14 42
75 375 37.5 112.5 15 45
80 400 40 120 16 48
85 425 42.5 127.5 17 51
90 450 45 135 18 54
Ideal body weight- For men: 50kg + 2.3 for each inch over 5 ft
(for each 2.5cm over 1.52m)
For women: 49kg + 1.7 for each inch over 5ft (for each 2.5cm
over 1.52m)
Patient already receiving xanthine (theophylline or
aminophylline)
Note: Common practice at ELHT is to omit the loading dose step
and give the maintenance infusion
Loading dose: Use the current serum level to calculate a loading
dose based on the expectation that each 0.5mg/kg of
theophylline
administered will result in a 1 microgram/mL increase in serum
theophylline concentration.
e.g.if the current theophylline serum level is 9 micrograms/mL
and a target level of 15 micrograms/mL is desired , a loading dose
of
3.75mg/kg aminophylline is needed (6 x 0.5mg/kg = 3mg/kg
theophylline = 3.75mg/kg aminophylline).
7/31/2019 Aminophylline Loading and Maintenance Dose v3
3/3
Aminophylline/Theophylline: Loading and maintenance dose
Prepared by N Fong, ELHT Pharmacy Approved by ELHE Medicines
Management Board
Date: 12/09/2011 V1 Review Date:12/09/2013
For oral:
Steady state theophylline levels are generally attained 3-4 days
after dose adjustment. If a satisfactory clinical response is not
achieved,
serum theophylline should be measured 4 6 hours after the last
dose.References:
BNF 61 March 2011
Aminophyllin 250mg/mL Injection (Goldshield Plc) Summary of
Product Characteristic Apr 2011
Phyllocontin Continus Tablets (Napp Pharmaceuticals Ltd) Summary
of Product Characteristic Sep 2009
Slo-Phyllin Capsules (Merck Serono) Summary of Product
Characteristic Jan 2010
Uniphyllin Tablets (Napp Pharmaceuticals Ltd) Summary of Product
Characteristic Feb 2011
Injectable Medicines Guide (Medusa) accessed June 2011
Injectable Drugs Guide Pharmaceutical Press 2011
Injectable Medicines Administration Guide UCL 3 rd Edition
