Pharmacokinetics of vaginal versus buccal misoprostol for labor induction at term

• DOI: 10.1111/cts.13306
• Publication Date: 2022-05-19T08:14:51Z
• Authors: Yana Vorontsova; David M. Haas; Kathleen Flannery; Andrea R. Masters; Larissa L. Silva; Rebecca C. Pierson; Brittany Yeley; Graham Hogg; David Guise; Michael Heathman; Sara K. Quinney
• Keywords: NONMEM

The IMPROVE study (NCT02408315) compared the efficacy and safety of vaginal buccal administration misoprostol for full-term, uncomplicated labor induction. This report compares pharmacokinetics between routes. Women greater than or equal to 14 years age undergoing induction 37 weeks gestation without significant complications were randomized 25 μg followed by 50 doses every 4 h. Misoprostol acid concentrations determined using liquid chromatography-tandem mass spectrometry first 8 h in a subgroup participants. A population pharmacokinetic model was developed NONMEM. Plasma (n = 469) from 47 women fit one-compartment nonlinear clearance model. absorption rate constant (ka ) dependent on both route dose administration: 0.724 (95% confidence interval, 0.54-0.92) h-1 ; 0.531 (0.37-0.63) 0.507 (0. 2-1. 4) 0.246 (0.103-0.453) . Relative bioavailability 2.4 (1.63-4.77). There no effect body index apparent 705 (431-1099) L/h volume distribution 632 (343-1008) L. area under concentration-time curve following 16.5 (15.4-17.5) pg h/ml 34.3 (32.5-36.1) administration. two times faster that vaginal, whereas higher buccal. Decreased time delivery observed with dosing may be due exposure