Saturday December 6, 2008
Dosing of Esmolol

Q: How much time does it take for esmolol to reach steady-state blood levels, if you don't use loading dose for esmolol infusion?

A: Using an appropriate loading dose, steady-state blood levels of Esmolol for dosages from 50-300 mcg/kg/min (0.05-0.3 mg/kg/min) are obtained within 5 minutes, otherwise it takes 30 minutes to reach steady-state without the loading dose. Steady-state blood levels of Esmolol increase linearly over this dosage range and elimination kinetics are dose-independent over this range.

Esmolol dosing guideline:

An initial loading dose of 0.5 milligrams/kg (500 micrograms/kg) infused over a minute duration followed by a maintenance infusion of 0.05 milligrams/kg/min (50 micrograms/kg/min) for the next 4 minutes is recommended. This should give a rough guide with respect to the responsiveness of ventricular rate.

After the 4 minutes of initial maintenance infusion (total treatment duration being 5 minutes), depending upon the desired ventricular response, the maintenance infusion may be continued at 0.05 mg/kg/min or increased step-wise (e.g. 0.1 mg/kg/min, 0.15 mg/kg/min to a maximum of 0.2 mg/kg/min) with each step being maintained for 4 or more minutes.

If more rapid slowing of ventricular response is imperative, the 0.5 mg/kg loading dose infused over a 1 minute period may be repeated, followed by a maintenance infusion of 0.1 mg/kg/min for 4 minutes. Then, depending upon ventricular rate, another (and final) loading dose of 0.5 mg/kg/min infused over a 1 minute period may be administered followed by a maintenance infusion of 0.15 mg/kg/min. If needed, after 4 minutes of the 0.15 mg/kg/min maintenance infusion, the maintenance infusion may be increased to a maximum of 0.2 mg/kg/min.

In the absence of loading doses, constant infusion of a single concentration of esmolol reaches pharmacokinetic and pharmacodynamic steady-state in about 30 minutes. Maintenance infusions (with or without loading doses) may be continued for as long as 24 hour.

Esmolol (Brevibloc) - rxlist.com