Flecainide excretion in human breast milk

Abstract

Healthy human volunteers who intended not to breast feed were placed on a regimen of 100 mg oral flecainide every 12 hours for 5 1/2 days beginning 1 day after parturition. Milk and blood samples were collected during the dosing period and for 2 days after the last dose. Concentrations of flecainide in milk and plasma were assayed by HPLC. Apparent steady-state levels of flecainide in both milk and plasma were achieved in most cases by day 4 of the study. Highest daily average concentration of flecainide in milk ranged from 270 to 1529 ng/ml for the 11 subjects. Mean +/- SD milk to plasma flecainide ratios were 3.7 +/- 3.5, 3.2 +/- 2.3, 3.5 +/- 2.1, and 2.6 +/- 0.7 on study days 2, 3, 4, and 5, respectively. After the last dose of flecainide, peak milk levels of the drug occurred at 3 to 6 hours and then declined monoexponentially. The half-life for elimination of flecainide from milk was 14.7 +/- 3.5 hours and is very similar to the plasma elimination half-life of flecainide in healthy human subjects. The mean milk to plasma ratios for flecainide after the last dose were 2.3 +/- 1.0 and 2.9 +/- 1.1 at 24 and 48 hours after the dose, respectively. Based on the pharmacokinetics of flecainide in infants, the expected average steady-state plasma concentration of flecainide in a newborn infant consuming all of the milk production of its mother (approximately 700 ml/day) would not be expected to exceed about 62 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Maternal, fetal, neonatal and breastmilk flecainide concentration during maternal therapy and lactation: A case report

“…The RID is often used to evaluate the effect of maternal medication use on the breastfed infant, and an RID below 10% is considered safe (5). Two previous studies estimated the RID instead of ecainide quanti cation in neonatal blood and found proportions of 3.6% and 4.5% (3,4). Our RID was 5.6%, which is quite comparable with the previous studies.…”

Prediction of Milk/Plasma Concentration Ratio of Drugs

“…The m/p ratios for these drugs are presented in Table 1. 9–74 The empiric m/p ratio ranged from 0.005 (implying very scarce transfer into milk) and up to 5.7 (meaning that milk level was almost sixfold higher than in maternal blood).…”

“…Table 2 9,11–20,22–32,34–56,58,60,61,65,67,71 presents the 3 values included in Atkinson's predictions for which there were sufficient literature values. Table 3 9–20,22–32,34…”

Medications and Breast-Feeding: A Guide for Pharmacists, Pharmacy Technicians, and other Healthcare Professionals Part II

“…2 Digoxin used by breast-feeding mothers results in undetectable infant serum concentrations (Table 3). [13][14][15][16][17][18][19][20][21][22][23][24][25][26]…”