85600
document
Pharmacokinetic study of RU 486 and its metabolites after oral administration of single doses to pregnant and non-pregnant women . RU 486 and three of its metabolites ( RU 42633-monodemethyl , RU 42848-didemethyl , and RU 42698-hydroxymetabolite ) were determined by HPLC in plasma from nine non-pregnant and 36 pregnant women . Each non-pregnant subject took an oral dose of RU 486 ( 25 , 100 , 400 and 600 mg consecutively ) once per menstrual cycle . Six of the nine women also received a dose of 200 mg . The 36 pregnant women were randomized into four groups which were given a single dose of 25 , 100 , 400 or 600 mg RU 486 . Blood samples were taken up to 120 h after dosing . Peak concentrations of RU 486 occurred on most occasions within 2 h. Plasma concentrations at 1 h and at 24 h increased in proportion to log dose . There was a wide variability ( up to ten-fold ) in the pharmacokinetic parameters within each dose group . Plasma concentrations of RU 42633 were similar to those of RU 486 but concentrations of RU 42848 and RU 42698 were much lower . As with RU 486 , the plasma concentrations of the metabolites were maintained at high levels for up to 48-72 h after dosing . The findings were consistent with a rapid metabolism of RU 486 to RU 42633 ; removal of the second methyl group leading to RU 42698 occurred much more slowly and to a much less extent than removal of the first . There appeared to be no significant differences between the non-pregnant and pregnant women in either the plasma concentrations or pharmacokinetic parameters of RU 486 and its metabolites .
85601
Intervention_Pharmacological
RU 486
85602
Intervention_Pharmacological
RU 486
85603
Intervention_Pharmacological
RU 42633-monodemethyl , RU 42848-didemethyl
85604
Intervention_Pharmacological
RU 42698-hydroxymetabolite
85605
Intervention_Pharmacological
RU 486
85606
Intervention_Pharmacological
RU 486
85607
Outcome_Physical
Blood samples
85608
Outcome_Physical
Peak concentrations of RU 486
85609
Outcome_Physical
Plasma concentrations
85610
Outcome_Physical
Plasma concentrations of RU 42633
85611
Outcome_Physical
plasma concentrations of the metabolites
85612
Outcome_Physical
RU 486 to RU 42633
85613
Participant_Condition
pregnant
85614
Participant_Condition
non-pregnant
85615
Participant_Sex
women
85616
Participant_Sample-size
nine
85617
Participant_Condition
non-pregnant
85618
Participant_Sample-size
36
85619
Participant_Condition
pregnant
85620
Participant_Sex
women
85621
Participant_Sample-size
36
85622
Participant_Condition
pregnant
85623
Participant_Sex
women
85624
Participant_Condition
non-pregnant
85625
Participant_Condition
pregnant
85626
Participant_Sex
women