see also:

• methylxanthines
• theophylline and methylxanthine poisonings and overdoses
• asthma
• paediatric asthma

• aminophylline is a one of the methylxanthines groupd of medications along with theophylline and caffeine.
• 400 mg theophylline is equivalent to 500 mg aminophylline
• ampoules: 250 mg /10 mL
• therapeutic serum levels: 55-110 umol/L (10-20 mcg/mL)
• each 1.25 mg/kg aminophylline results in a plasma theophylline increase of approximately 11 umol/L (2 mcg/mL)
• it's main usage is in severe asthma in extremis or not responding to iv salbutamol, and thus generally should be used in a resuscitation cubicle or similar with ECG monitoring
• it must be given in a separate iv line to iv salbutamol
• if the patient is not already taking theophylline, an iv loading dose is given.
• patients who have taken theophylline containing preparations in past 24 hours need the loading dose reduced by 50% or not given.
• elimination rates (and thus maintenance infusion dose needed), is dependent on age, weight, smoking status, hepatic function (and thus also cardiac function)

• Not suitable for IM admin; CHF; cardiac, renal, hepatic, circulatory impairment; cor pulmonale; acute pulmonary oedema, febrile illness, myocardial injury; hypertension; chronic alcoholism; pneumonia; influenza (incl vaccination); hyper/ hypothyroidism; hypertension; tachyarrhythmia; gastroesophageal reflux; angina; epilepsy; peptic ulcer; diabetes; glaucoma; COPD; rapid IV admin; elderly, pregnancy, lactation, children esp premature, neonates

• see methylxanthines

• incompatible with amiodarone, corticotropin, diltiazem, dobutamine, epinephrine, hyaluronidase, hydralazine, hydroxyzine, insulin, isoprenaline, levorphanol, meperidine, norepinephrine, ondansetron, prochlorperazine, verapamil, salbutamol
• compatible with magnesium sulphate, morphine, metoclopramide, methylprednisolone, potassium chloride, propofol, heparin

• add 25mg/kg aminophylline to 5% dextrose to make total of 50mls = 0.5mg/kg/ml

• 10mg/kg (max. 500mg) over 1 hour = 20ml/hr if weight < 50kg, otherwise 500mg/(0.5mg/kg x weight in kg) ml/hr

• age 1-9 years:
  • rate = 1.1mg/kg/hr = 2.2ml/hr if using 0.5mg/kg/ml infusion as above
• age 10 yrs and over:
  • rate = 0.7mg/kg/hr = 1.4ml/hr if using 0.5mg/kg/ml infusion as above

• 6mg/kg over 30min
• ie. Vd x 10mg/L theophylline and Vd = 0.5L/kg lean body mass

• Clearance x 10mg/L theophylline
• Clearance = 0.041 L/kg/h in normal adults but variable → monitor serum levels
• Clearance higher in children = 0.06-0.9 L/kg/h
  • BUT neonates & infants have the SLOWEST CLEARANCE

• children 9-12yrs: 0.8mg/kg/hr
• children 12-16yrs: smokers: 0.8mg/kg/hr non-smokers: 0.6mg/kg/hr
• adults:
  • smokers: 0.8mg/kg/hr
  • non-smokers: 0.5mg/kg/hr
  • impaired liver or cardiac function: 0.25mg/kg/hr¹⁾