Dose Rate in Medical Practice

Introduction to Dose Rates

• The American Heart Association recommends expressing medication administration rates in terms of dose rates, such as mcg/min, when describing medication administration protocols 1, 2
• The American College of Cardiology guidelines describe esmolol administration as "50-mcg/kg/min infusion" with incremental increases in "50-mcg/kg/min" to a maximum of "200 mcg/kg/min" 3, 4

Medication Administration

• In hypertensive emergencies, sodium nitroprusside is dosed at "0.3-0.5 mcg/kg/min" with incremental increases of "0.5 mcg/kg/min" to achieve blood pressure targets 1, 2
• Pediatric medications like epinephrine are administered at "<0.3 mcg/kg per minute" for β-adrenergic effects and ">0.3 mcg/kg per minute" for α-adrenergic effects 5, 6

Calculating Infusion Rates

• The formula to determine the actual infusion rate (volume/time) from a dose rate is: Infusion rate (mL/h) = [weight (kg) × dose (mcg/kg/min) × 60 (min/hour)] ÷ concentration (mcg/mL) 6

Clinical Applications

• The American Heart Association suggests that dose rates are particularly important for medications with narrow therapeutic windows, such as vasoactive drugs and inotropes 5, 2
• When titrating medications to effect, clinicians adjust the dose rate (mcg/min) rather than the infusion rate (mL/hr) to achieve the desired clinical response 1, 3