Table 1

A comparison of factors affecting prescription, administration and monitoring when using intravenous aminophylline and intravenous salbutamol infusions and boluses^W20—25

		Aminophylline	Salbutamol infusion	Salbutamol bolus
Administration details	Reconstitution	▸ No, solution	▸ No, solution	▸ No, solution
	Dilution	Yes: suggested concentrations 1 mg/mL Has been used neat (25 mg/mL) in fluid restriction (central line preferred as highly irritant)	Yes, suggested concentration of 200 µg/mL for central line and 10–20µg/mL for peripheral line Has been used neat (1 mg/mL) in fluid restriction (central line only)	Yes, suggested concentration of 200 µg/mL for central line and 10–20 µg/mL for peripheral line Has been used neat (1 mg/mL) in fluid restriction (central line only)
	Calculation complexity	▸ Yes: multistep calculation for dilution and rate	Yes: multistep calculation for dilution and rate Conversion between milligrams and micrograms Conversion between hours and minutes	Yes: multistep calculation for dilution and rate Conversion between milligrams and micrograms
	Therapeutic risk	▸ High: narrow therapeutic index drug	▸ High	▸ High
	Need to use part vials	Yes: for loading dose Yes/no: for maintenance infusion depending on house recommendations	Yes Also for larger patients need to use multiple vials to avoid multiple bag changes	▸ Yes
	Different strengths available	▸ No	▸ Yes	▸ Yes
	Need for infusion pump	▸ Yes	▸ Yes	▸ Yes
	Other	Loading dose and maintenance rate will have different rates and potentially different concentrations Stable for 24 h once dilutes	Protect from light Stable for 24 h once diluted	Protect from light Stable for 24 h once diluted
	Risk score	▸ Amber: moderate risk	▸ Amber: moderate risk	▸ Amber: moderate risk
Fluid compatibility	Additive	Sodium chloride 0.9% and 0.45% Dextrose 5% Combination of the above Combination of the above with up to 20 mmol/ 500 mL of potassium chloride	Sodium chloride 0.9% and 0.45% Dextrose 5% Combination of the above	Sodium chloride 0.9% and 0.45% Dextrose 5% Combination of the above
Fluid compatibility	Y-site	As above Aminophylline is alkaline (avoid acidic drugs)	As above Salbutamol is acidic (avoid alkaline drugs)	As above Salbutamol is acidic (avoid alkaline drugs)
Monitoring	Levels	Yes 30 min after completion of loading dose At least daily thereafter (6–12 h after rate changes)	No	No
	U&Es	▸ Yes: potassium at least daily	Yes: potassium, recommended twice daily Yes: blood glucose, recommended twice daily	Yes: potassium Yes: blood glucose
	ECG	Yes: during loading dose Often continues during maintenance infusion	▸ Yes	▸ Yes
	Other	HDU bed recommended if available (administration should not be delayed if unavailable) BP and heart rate	HDU bed recommended BP and heart rate	May be given in A&E BP and heart rate
Prescription ease	Dosage	Varies with age Use ideal body weight Calculate and prescribe different doses for loading dose and maintenance infusion: use standard concentration recommended 2 prescriptions, one for loading dose, one for maintenance infusion No blind loading dose recommended for patient on theophylline therapies at home or with renal/liver impairment Cap loading dose at 500 mg Adjust rates depending on levels and side effects	Varies with age Vast range of doses: 0.1–10 µg/kg/min. (Although note that when prescribing for children the maximum adult dose suggested in the BNF of 20 µg/min will often be surpassed. A total dose cap should be considered for larger children) Conversion mg-micrograms Conversion hours-minutes Difficult to use a standard concentration due to variability in doses Adjust rates depending on clinical picture and side effects	Set dose (may be repeated if needed) Cap dose at 250 µg Over 5–20 min
Drug particulars		High metabolic interaction risk – Aciclovir, azole antifungals, macrolides, quinolones, calcium channel blockers, etc., will raise theophylline concentrations – Some antiepileptics, rifampicin, tobacco smoke will reduce theophylline concentrations Additive hypokalaemia with common concomitant treatments (steroids, salbutamol) Pharmacokinetics vary greatly with age: – Neonates and infants under 6 months slower clearance than adults – Infants and children up to 9–10 faster clearance than adults – Gender different clearance in adolescents Requires pharmacy input for dosage adjustments, how long to stop, how much to re-load with etc.	Low metabolic interaction risk – Antidiabetic agents Additive hypokalaemia with common concomitant treatments (steroids, aminophylline)	Low metabolic interaction risk – Antidiabetic agents Additive hypokalaemia with common concomitant treatments (steroids, aminophylline)
Licensing		▸ Licensed in children older than 6 months	▸ Licensed for children older than 12 years	▸ Licensed for children older than 12 years

A&E, accident and emergency; BNF, British National Formulary; HDU, high-dependency unit; U&E, urea and electrolytes.