Remifentanil for Labor Analgesia

Last updated: February 9, 2026

Rapid onset, peak 1-2 min. Context sensitive half-time (nonpregnant) = 3 minutes. Metabolism is by non-specific esterases; inactive metabolites.

Dosing: remifentanil 4 mg in 250 mL of 0.9% NaCl (16 mcg/mL).

Start IV at 0.05 mcg/kg/min. (For a 70 kg individual, this is about 13 mL/hr.) Rate adjustments of 0.02 mcg/kg/min may be made every 5-10 minutes.

Pain scores will be around 4-6 out of 10.

For a single bolus, consider 20-40 mcg (0.25-0.5 mcg/kg).

Epidural morphine → biphasic ventilatory depression; recommend monitoring for 24 hr.