Pharmacokinetics of Ketamine Transfer Into Human Milk

Area of Science:

• Pharmacology
• Neonatal Medicine
• Lactation Studies

Background:

• Postpartum depression affects over 15% of deliveries.
• Ketamine is an N-methyl-D-aspartate (NMDA) antagonist used for treatment-resistant depression, suicidality, and postpartum depression.
• Limited research exists on ketamine's safety during lactation.

Purpose of the Study:

• To quantify ketamine and its metabolite norketamine levels in human milk.
• To assess the safety of ketamine use during lactation for infants.

Main Methods:

• Human milk samples from 4 participants treated with ketamine infusions were analyzed.
• Liquid chromatography-mass spectrometry was used to measure ketamine and norketamine concentrations.
• Absolute and relative infant doses (RID) were calculated.

Main Results:

• Ketamine absolute infant dose: 0.003–0.017 mg/kg/day.
• Norketamine absolute infant dose: 0.005–0.018 mg/kg/day.
• Relative infant doses (RID) for ketamine were 0.34%–0.57%, and for norketamine were 0.29%–0.95%.

Conclusions:

• Ketamine and norketamine transfer into human milk is minimal.
• Relative infant doses are below 1%, well within accepted safety thresholds.
• Findings suggest ketamine is likely safe for breastfeeding infants.