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Dive into the research topics where Christine Klipping is active.

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Featured researches published by Christine Klipping.


Contraception | 2008

Suppression of ovarian activity with a drospirenone-containing oral contraceptive in a 24/4 regimen

Christine Klipping; Ingrid Duijkers; Dietmar Trummer; Joachim Marr

BACKGROUND This study was conducted to compare ovarian activity of an oral contraceptive containing drospirenone (drsp) 3 mg plus ethinylestradiol (EE) 20 mcg administered in 24/4 regimen compared with the conventional 21/7 regimen, during intended use and following predefined dosing errors. STUDY DESIGN Women aged 18-35 years who ovulated or had a follicular diameter of >or=15 mm on or before Day 23 during a pretreatment cycle were admitted into this double-blind, randomized study. Participants underwent 3 treatment cycles with drsp 3 mg/EE 20 mcg in a 24/4 (n=52) or a 21/7 (n=52) regimen. In the third treatment cycle, the initial three pills in both groups were replaced with placebos. Ovarian activity was classified using the Hoogland scale during pretreatment and during Cycles 2 and 3. RESULTS Suppression of ovarian activity was more pronounced with the 24/4 regimen--the odds ratio for a lower Hoogland score (i.e., greater ovarian suppression) with the 24/4 regimen compared with the conventional 21/7 regimen were 6.01 (95% CI: 2.29-17.94) and 3.06 (95% CI: 1.44-6.65) for Cycles 2 and 3, respectively. More women in the 24/4 regimen group had no ovarian activity 87.8% vs. 56.0% during Cycle 2 and 55.1% vs. 30.0% during Cycle 3. The 24/4 regimen was associated with a more consistent suppression (less fluctuation) of endogenous estradiol. CONCLUSION The drsp 3 mg/EE 20 mcg oral contraceptive in a 24/4 regimen was associated with greater ovarian suppression (despite intentional dosing error), which results in decreased hormonal fluctuations, and may increase contraceptive efficacy with the low-dose formulation.


Contraception | 2008

Ovulation inhibition with four variations of a four-phasic estradiol valerate/dienogest combined oral contraceptive : results of two prospective, randomized, open-label studies

Jan Endrikat; Susanne Parke; Dietmar Trummer; Werner Schmidt; Ingrid Duijkers; Christine Klipping

BACKGROUND Attempts to improve the tolerability of combined oral contraceptives (COCs) have included the substitution of ethinylestradiol (EE) with 17beta-estradiol (E2). However, this has proved unsatisfactory, specifically in terms of cycle control. To improve upon the poor cycle control seen previously, E2 [in the form of estradiol valerate (E2V); 1 mg of E2V contains 0.76 mg of E2] was combined with dienogest (DNG) in a novel four-phasic regimen. In the current studies, the ovulation-inhibition potency of four variations of this regimen was assessed. STUDY DESIGN Two randomized, open-label, Phase II studies were performed. The first study compared two regimens (Regimens 1A and 2A) with similar dosages of DNG but different lengths of application. Having established in Study 1 that the length of application of Regimen 2A was most suitable, but that the dosages of DNG were too low for effective ovulation inhibition, a second study, which compared two regimens (Regimens 2B and 2C) with similar lengths of application but with increased dosages of DNG, was undertaken. The primary efficacy variable in both studies was the proportion of women with a Hoogland score of 5 or 6 during Cycle 2. RESULTS The full analysis set comprised 192 and 203 women in Studies 1 and 2, respectively. In Study 1, 10 women (10.9%) in Regimen 1A and 6 women (6.4%) in Regimen 2A had a Hoogland score of 5 or 6. In Study 2, three women (3.1%) in Regimen 2B and one woman (1.0%) in Regimen 2C had a Hoogland score of 5 or 6. There were no safety concerns with any of the regimens. CONCLUSION The results of these studies identified a four-phasic COC preparation comprising E2V/DNG that provides efficient ovulation inhibition. It is expected that this regimen will lead to an innovative COC containing E2 instead of EE.


Gynecological Endocrinology | 2009

Polycystic ovaries, as defined by the 2003 Rotterdam consensus criteria, are found to be very common in young healthy women.

Ingrid Duijkers; Christine Klipping

BACKGROUND The criteria for polycystic ovaries (PCO) as defined by the 2003 Rotterdam consensus are based on the follicle number and ovarian volume, which decrease with age. A study was performed to assess the influence of age on the PCO prevalence. In addition, the relation between follicle number and ovulation day was studied. METHODS Assessments were done in a spontaneous menstrual cycle in 171 healthy volunteers. The ovulation day and cycle duration were recorded. Transvaginal ultrasonography was performed between cycle day 6 and 9 to determine the follicle number and ovarian volume. RESULTS In the age groups between 18 and 22, 23 and 27, 28 and 32, 33 and 37, and 38 and 40 years, the prevalence of PCO was 83-84%, 66-84%, 42-79%, 19-33%, and 0-33%, respectively. Most PCO subjects had ovulatory cycles. The follicle number and ovarian volume decreased with age. There was a positive correlation between the follicle number and the ovulation day. CONCLUSIONS PCO were found to be very common in young women. The follicle number and ovarian volume decreased with age, and therefore also the PCO prevalence decreased with age. We believe the PCO criteria should be reconsidered and adapted to the womans age. Ovulation occurred later with increasing follicle number.


The European Journal of Contraception & Reproductive Health Care | 2010

Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17β-oestradiol on ovarian function in comparison to a monophasic combined oral contraceptive containing drospirenone and ethinylestradiol

Ingrid Duijkers; Christine Klipping; Paul Grob; Tjeerd Korver

Objective To compare the effects on ovarian activity of two oral contraceptives containing nomegestrol acetate (NOMAC)/17β-oestradiol (E2) or drospirenone (DRSP)/ethinylestradiol (EE). Methods In this open-label, randomised, six-cycle study, 32 subjects using NOMAC/E2 (2.5–1.5 mg; 24/4-day regimen) were compared to 16 subjects using DRSP/EE (3 mg–30 μg; 21/7-day regimen). Measurements included serum oestradiol, progesterone, follicle stimulating hormone (FSH) and luteinising hormone (LH), and ultrasonography of follicular diameter. Results No ovulations occurred during treatment. Progesterone was fully suppressed, with mean maximum values <2 nmol/l in both groups over all cycles. For NOMAC/E2, mean maximum follicular diameter decreased from 19.3 mm before treatment to between 6.9 and 8.2 mm during treatment, with no subject having a follicular diameter ≥15 mm. For DRSP/EE, a decrease from 19.6 to between 7.4 and 10.8 mm was observed, with two subjects (12.5%) having a maximum follicle diameter ≥15 mm. These findings were consistent with observed FSH reductions; full suppression of LH surges was observed in both groups. Post-treatment return of ovulation in both groups occurred on average 21 days after the last active tablet intake. Conclusions NOMAC/E2 achieves consistent ovulation inhibition, with suppressive effects on the ovaries at least similar to those of DRSP/EE.


Contraception | 2002

An open label, comparative study of the effects of a dose-reduced oral contraceptive containing 20 μg ethinyl estradiol and 100 μg levonorgestrel on hemostatic, lipids, and carbohydrate metabolism variables

Jan Endrikat; Christine Klipping; M. Cronin; Christoph Gerlinger; A. Ruebig; Werner Schmidt; B. Düsterberg

In this open label, randomized study we compared the influence of a dose-reduced oral contraceptive containing 20 microg ethinyl estradiol (EE) and 100 microg levonorgestrel (20 EE) with a reference preparation containing 30 microg EE and 150 microg levonorgestrel (30 EE) on hemostatic, lipids, and carbohydrate metabolism variables. Data from 48 volunteers were obtained. The direction of the change (increase or decrease) in most of the hemostatic variables were similar in both treatment groups. In particular, prothrombin fragment 1 + 2 increased during treatment, reaching a median percent change of 40% in the 20 EE group and of 17% in the 30 EE group after one year. D-Dimer fibrin split products remained virtually unchanged, with no change at Cycle 13. The median HDL2 cholesterol levels decreased by 26% in the 20 EE group and by 39.8% in 30 EE group (p = 0.0045 for group difference) after one year. The median one year change for LDL cholesterol was 3.23% in the 20 EE group, compared to 25% in the 30 EE group, for VLDL 11.1% compared to 38.8%, respectively, and for total triglycerides 10.0% compared to 37.5%, respectively. The median absolute change for the area under the curve (AUC)(0-3h) for glucose at treatment Cycle 13 was 41.25 mmol/L x min in the 20 EE group and 73.50 mmol/L x min in the 30 EE group. The AUC(0-3h) insulin at treatment Cycle 13 decreased in the 20 EE group by 1635.0 pmolL x min and increased in the 30 EE group by 11797.5 pmolL x min (p = 0.0491 for group difference). Both study treatments were safe and well tolerated by the volunteers. In conclusion, the balanced one-third dose reduction in this new oral contraceptive evoked similar effects on the hemostatic variables, but favorable results for the lipid and carbohydrate profiles.


Drugs in R & D | 2011

Hemostatic effects of a novel estradiol-based oral contraceptive: an open-label, randomized, crossover study of estradiol valerate/dienogest versus ethinylestradiol/levonorgestrel.

Christine Klipping; Ingrid Duijkers; Susanne Parke; Uwe Mellinger; Marco Serrani; Wolfgang Junge

AbstractBackground: A novel estradiol-based combined oral contraceptive (COC) is currently available in many countries worldwide, including Europe and the US. Based on previous studies, it is expected that this estradiol-based COC will have a reduced hepatic effect compared with COCs containing ethinylestradiol with regard to proteins controlling the hemostatic balance. Objective: The aim of this study was to compare the hemostatic effects of the estradiol valerate/dienogest COC with a monophasic low-estrogen dose COC containing ethinylestradiol/levonorgestrel. Study Design: Healthy women aged 18–50 years were randomized to receive a COC containing estradiol valerate/dienogest (2 days estradiol valerate 3 mg, 5 days estradiol valerate 2mg/dienogest 2 mg, 17 days estradiol valerate 2mg/dienogest 3 mg, 2 days estradiol valerate 1 mg, 2 days placebo) or ethinylestradiol 0.03mg/levonorgestrel 0.15mg in a crossover study design. Women received each treatment for three cycles, with two washout cycles between treatments. The primary efficacy variables were the intra-individual absolute changes in prothrombin fragment 1 + 2 and D-dimer from baseline to cycle three. Results: Data from 29 women were assessed. Intra-individual absolute changes in prothrombin fragment 1 + 2 and D-dimer from baseline to cycle three were less pronounced with estradiol valerate/dienogest than with ethinylestradiol/ levonorgestrel. Conclusion: The novel COC containing estradiol valerate/dienogest had similar or less pronounced effects on hemostatic parameters than ethinylestradiol/ levonorgestrel.


The Journal of Clinical Pharmacology | 2012

Ovulation‐Inhibiting Effects of Dienogest in a Randomized, Dose‐Controlled Pharmacodynamic Trial of Healthy Women

Christine Klipping; Ingrid Duijkers; Ageeth Remmers; Thomas Faustmann; Christian Zurth; Stefan Klein; Barbara Schuett

Dienogest offers pharmacological advantages for the effective treatment of endometriosis and for use in contraception and hormone replacement therapy. This pharmacodynamic study investigated the ovulation‐inhibiting effects of dienogest monotherapy in healthy women. Dienogest was administered at 0.5, 1, 2, or 3 mg daily for up to 72 days to women aged 18 to 35 years (n = 102). Ovarian activity was assessed pretreatment and during 2 treatment periods (days 0–36 and days 37–72) by the Hoogland score, based on follicle size and serum estradiol and progesterone levels. Additional hormonal parameters and endometrial thickness were assessed. Hoogland scoring indicated ovulation in all women pretreatment, decreasing to 3 of 21, 1 of 23, 0 of 20, and 0 of 23 women in the 0.5‐, 1‐, 2‐, and 3‐mg groups, respectively (per‐protocol set). Maximum serum estradiol concentrations were similar to pretreatment levels in the 0.5‐ or 1‐mg group and decreased moderately (within physiologic levels) in the 2‐ or 3‐mg group. Endometrial thickness was reduced by all dienogest doses. Hormonal changes during follow‐up indicated resumption of ovulation in most women, shortly after treatment cessation. Dienogest ≥2 mg daily provides moderate suppression of estradiol production and reliable ovulation inhibition, which reverses rapidly after treatment cessation.


Fertility and Sterility | 2001

Pharmacodynamic effects and plasma pharmacokinetics of single doses of cetrorelix acetate in healthy premenopausal women

Katharina Erb; Christine Klipping; Ingrid Duijkers; Birgit Pechstein; Armin Schueler; Robert Hermann

OBJECTIVE To investigate the pharmacodynamic effects and plasma pharmacokinetics of single subcutaneous doses of cetrorelix acetate in healthy premenopausal women. SETTING Phase I clinical research unit. PATIENT(S) Healthy, premenopausal women aged 19 to 35 years. INTERVENTION(S) Single subcutaneous morning doses of cetrorelix acetate (1, 3, or 5 mg peptide base) were investigated in a randomized, single-blind, placebo-controlled, parallel-group design. After a control cycle, 36 women received cetrorelix acetate (12 per dose) and 12 received placebo on the eighth individual cycle day. Transvaginal ultrasound was performed, and blood samples for LH, FSH, E2 were collected during both cycles and for pharmacokinetics up to 168 hours after dosing. The serum hormone levels were determined by electrochemicoluminescence immunoassay and plasma cetrorelix concentrations by radioimmuno assay. RESULTS Cetrorelix acetate administration led to a rapid, marked, and reversible suppression of serum LH, E2, and to a lesser extent FSH concentrations. The median intra-individual shifts between treatment and control cycle were -1.0, 4.0, 8.0, and 9.5 days for serum LH maximum and -1.0, 4.5, 7.0, and 10.0 days for ovulation following placebo or 1, 3, and 5 mg cetrorelix acetate, peptide base, respectively. The area under the concentration-time curve (AUC) and peak cetrorelix concentrations in plasma (Cmax) increased proportionally with dose. CONCLUSIONS Cetrorelix acetate showed pronounced and reversible LH and E2 suppression and a dose-dependent postponement of LH surge and ovulation after single subcutaneous administrations to healthy premenopausal women. Dose proportionality over the range of 1 mg to 5 mg cetrorelix acetate, peptide base was demonstrated.


The Journal of Clinical Pharmacology | 2003

Pharmacokinetic/Pharmacodynamic Modeling of Luteinizing Hormone (LH) Suppression and LH Surge Delay by Cetrorelix after Single and Multiple Doses in Healthy Premenopausal Women

Nelamangala V. Nagaraja; Birgit Pechstein; Katharina Erb; Christine Klipping; Robert Hermann; Mathias Locher; Hartmut Derendorf

Cetrorelix (CET) is a potent luteinizing hormone—releasing hormone (LH‐RH) antagonist and is used to prevent premature ovulation in IVF (in vitro fertilization) procedures. The objective of the present study was to develop a pharmacokinetic/pharmacodynamic (PK/PD) model for the LH suppression and LH surge delay after single doses (SD) and multiple doses (MD) of CET in healthy premenopausal women without ovarian stimulation. CET was given by subcutaneous route (SD, 0.25, 0.5, or 1 mg) on cycle day 3 and as similar multiple once‐a‐day doses from cycle day 3 to day 16 in two consecutive menstrual cycles. The concentration‐time data of CET and LH were used for PK/PD modeling. A two‐compartment model described the PK of CET with median terminal half‐life estimates of 9.2 and 54.5 hours after SD and MD, respectively. An indirect‐response Emax model was used to describe the LH suppression and the LH surge delay. LH suppression was linked to plasma concentrations of CET, while the delay in the LH surge was linked to the PK of CET through a hypothetical effect compartment. Since the SD regimen on day 3 did not cause significant delay, these values were used as controls in the analysis of surge delay in MD data. The IC50 (for suppression) estimate was 0.73 ng/ml for SD, and EC50 (surge delay) was 1.42 ng/ml for MD. The PK/PD model adequately described the LH suppression and the surge delay.


Gynecological Endocrinology | 2005

Length of the menstrual cycle after discontinuation of oral contraceptives

Ingrid Duijkers; Lonneke Engels; Christine Klipping

Objective To investigate whether the first cycle after stopping oral contraceptive (OC) intake had a normal duration. Methods A retrospective study was performed in 680 women, 300 non-OC users and 380 women discontinuing OC intake. The length of one or two menstrual cycles was recorded. Results In the non-user group, the median duration of both the first and second cycle was 29 days (range 18–97 and 20–56 days, respectively). In the OC user group the median duration from withdrawal bleeding until next menstruation was 30 (15–82) days. The second cycle lasted 29 (17–122) days. The duration of the first post-treatment cycle was not significantly different from the next cycle or the cycle length in non-users. When the subjects were divided into different age categories, a significantly longer first post–treatment cycle was observed in the group aged 18–24 years, but a shorter first post-treatment cycle in the group aged 25–29 years. No differences were seen in the higher age groups. The ethinyl estradiol dose of the OC preparation did not influence the results. Conclusions The first cycle after OC discontinuation had a normal duration.

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Joachim Marr

Bayer Schering Pharma AG

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Jan Endrikat

Bayer HealthCare Pharmaceuticals

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Susanne Parke

Bayer HealthCare Pharmaceuticals

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Christoph Gerlinger

Bayer HealthCare Pharmaceuticals

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