title: Comparing the pharmacokinetics of doxylamine/pyridoxine delayed-release combination in nonpregnant women of reproductive age and women in the first trimester of pregnancy.
abstract: Although Diclectin (doxylamine/pyridoxine delayed-released combination) is widely used in Canada, its pharmacokinetics (PK) during pregnancy has never been described. The objective of this study was to compare the PK of doxylamine/pyridoxine delayed-released combination in pregnant versus nonpregnant women. The apparent clearances (CL) of doxylamine and pyridoxal 5'-phosphate (PLP; the active metabolite of vitamin B(6) ) during the first-trimester pregnancy in women who participated in a Diclectin randomized trial were compared with those of healthy, adult, nonpregnant women who participated in a voluntary PK trial. Eighteen nonpregnant women were compared with 50 pregnant women who were treated with Diclectin. There was no difference in the apparent CL of doxylamine in women in their first trimester of pregnancy when compared with nonpregnant women on day 4 (median = 196.7 vs 249.5 mL/h/kg, respectively, P = .065), day 8 (median = 248.4 vs 249.5 mL/h/kg, respectively, P = .82), and day 15 (median = 200.9 vs 249.5 mL/h/kg, respectively, P = .55). No difference was found in the apparent CL of PLP on day 15 (median = 342.3 vs 314.7 mL/h/kg, respectively, P = .92). There was no pregnancy-induced effect in the apparent CL of either doxylamine or PLP in women during the first trimester of pregnancy despite the existence of morning sickness.
authors: University of Toronto, Toronto, Ontario, Canada.
authors: Ilan
authors: I
authors: Matok
authors: Shannon
authors: S
authors: Clark
authors: Steve
authors: S
authors: Caritis
authors: Menachem
authors: M
authors: Miodovnik
authors: Jason
authors: J
authors: Umans
authors: Gary
authors: G
authors: Hankins
authors: Gideon
authors: G
authors: Koren
mesh_terms: D000293:Adolescent; D000328:Adult; D000932:Antiemetics / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000493:pharmacokinetics; D004025:Dicyclomine; D004311:Double-Blind Method; D004319:Doxylamine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy / Q000378:metabolism*; D011261:Pregnancy Trimester, First / Q000378:metabolism; D011736:Pyridoxine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D055815:Young Adult
chemical_list: D000932:Antiemetics; D003692:Delayed-Action Preparations; D004338:Drug Combinations; C004454:dicyclomine, doxylamine, pyridoxine drug combination; D004025:Dicyclomine; D004319:Doxylamine; D011736:Pyridoxine