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A total of 10 epileptic mothers treated with ethosuximide (ES) as well as their 13 newborns were included in this study. At birth foetal/maternal serum concentration ratios were 0.97 +/- 0.02 (n = 7) and ES half-lives in three neonates were 32, 37 and 38 h. The breast milk concentrations of ES were similar to those in maternal serum (milk/serum: 0.86 +/- 0.08, n = 12) and the nursed infants maintained serum levels between 15 and 40 micrograms/ml. Two major malformations (bilateral clefting, hare-lip) were observed in two neonates whose mothers received either ES/PB or ES/PMD comedication. The number of minor anomalies was higher in the ES group (6.2, n = 12) than in the pair-matched control group of infants born to non-epileptic mothers (2.1, n = 10). Neonatal behaviour complications occurred in seven infants, two of them were severely affected. [ABSTRACT FROM AUTHOR]

The protein binding of diazepam (D) and its major active metabolite N- desmethyl diazepam (DD) was investigated in vitro in the serum of 14 mothers at birth, 21 foetuses at birth, in 100 neonates between 1 and 11 days of age and in 16 control subjects. The free (unbound) fractions of D and DD in the foetus were similar to those in the controls, but lower than those in the mothers. During the first day of life the free fractions of D and DD doubled in the neonates and subsequently declined slowly to reach near control levels at 1 week of age. The sharp increase and slow decrease of the free fractions of D and DD during the first postnatal week was closely paralleled by sharply increasing and decreasing free fatty acid (FFA) concentrations. Bilirubin and albumin levels were of lower importance in regard to the protein binding of D and DD. These results indicate that the greatly increased FFA levels shortly after birth result in increased free fractions of D and DD. Because of the known immaturity of the neonatal hepatic elimination capacity, these elevated free fractions may result in elevated free concentrations of the two compounds, which may help to explain the adverse effects observed clinically in some D-exposed neonates. [ABSTRACT FROM AUTHOR]

Objective: Contraception is recommended for female patients during ursodeoxycholic acid (UDCA) treatment for the potential teratogenic effect of this bile acid, and the aim of our study was to determine whether this treatment affects the bioavailability of ethinylestradiol (EE2)., Methods: In this double-blind, randomised study, we measured EE2 pharmacokinetics in eight healthy volunteers randomly allocated to receive oral contraceptive (30 microg EE2 and 75 microg gestodene) plus either UDCA (8-10 mg/kg per day) or placebo for 21 days during the first of three consecutive menstrual cycles. After a washout period during the second cycle, the subjects received the alternative treatment during the third menstrual cycle. Serum EE2 and UDCA were measured using radioimmunoassay and gas chromatography-mass spectrometry, respectively., Results: The profile for serum EE2 concentration was similar during UDCA (mean maximum serum concentration 177 pg/ml, SEM 59) and during placebo treatment (153 pg/ml, SEM 62), and mean area under the curve (AUC) was 1374 pg/h per ml (SEM 580) and 1320 pg/h per ml (SEM 551) during the two regimens, respectively. The point estimates and 90% confidence intervals of UDCA/placebo ratios for EE2 AUC and for maximum serum concentration were 1.1 (0.8-1.5) and 1.2 (1.0-1.4), respectively. Mean serum triglycerides concentration increased from 58.3 mg/dl (SEM 6.8) at enrolment to 91.4 mg/dl (SEM 10.7) during placebo (P < 0.01) and to 88.6 mg/dl (SEM 13.7) during UDCA treatment (P < 0.05). During UDCA treatment, serum enrichment with this bile acid and with the metabolite iso-UDCA was 29% (16%) and 3% (2%), respectively., Conclusion: Co-administration with UDCA does not affect the bioavailability of EE2 in healthy volunteers, indicating that contraceptive efficacy is not affected.

This study investigated the pharmacokinetics of a dose-reduced oral contraceptive containing 20 microg ethinylestradiol (EE) + 100 microg levonorgestrel (LNG) in 18 young, healthy females. Serum levels of EE and LNG were determined after single and repeated daily oral administration over three treatment cycles, each consisting of 21 treatment days followed by a 7-day treatment-free period. Additionally, the time courses of sex hormone-binding globulin (SHBG), corticoid-binding globulin (CBG) and total and free testosterone serum levels were analyzed. Both active ingredients were rapidly absorbed and maximum concentrations in serum were reached between, on average, 1 and 2 h after single and multiple administrations, respectively. Concentrations of EE increased during repeated daily administration. An approximate two-fold accumulation was calculated based on the comparison of EE area under the curve (AUC) (0-24 h) values determined after the first and the last tablet administration within a treatment cycle. LNG serum concentrations also increased during repeated daily administration, reaching steady-state levels after about 11 days. Based on the comparison of AUC (0-24 h) values determined after the first and the last tablet administration, LNG accumulated approximately by a factor of 3 within a treatment cycle. Steady-state pharmacokinetics of LNG were similar at the end of the first and the third treatment cycles, indicating no further accumulation of LNG beyond a treatment cycle under long-term use of this combined oral contraceptive. The clearance and volume of distribution of LNG decreased and the terminal half-life increased after repeated daily administration, compared with single administration. These effects have also been reported for other LNG/EE combinations. SHBG serum concentrations increased during repeated daily intake by, on average, 1.5-1.6-fold, and for CBG, an average increase of 1.4-1.8-fold was found. Although free testosterone concentrations declined during repeated daily administration by about 40%, total testosterone remained relatively unchanged at a low level. In conclusion, the pharmacokinetics of EE and LNG determined in the present study were in good agreement with those previously reported for 30 microg EE + 150 microg LNG, taking the 33% dose reduction into account.