Pharmacokinetics of three bioequivalent norethindrone/mestranol-50ug and three norethindrone/ethinyl estradiol-35ug oc formulations: Are “low-dose” pills really lower?

Brody, Steven A.; Turkes, A.; Goldzieher, Joseph W.

doi:10.1016/0010-7824(89)90092-9

Cited by 47 publications

(21 citation statements)

References 13 publications

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“…Similar find ings have already been described during clinical studies with other oral contraceptives [8]. The absolute AUC values observed in this study agree with corresponding values reported in the literature for these and other con traceptive formulations which contain EE2 at a dosage of 30 pg per pill [1,4,5,9,10]. There was no difference in either AUC (0-4 h) or AUC (0-24 h) or the change in AUC (0-4 h) values during the cycle between the two contraceptive formulations investigated in this study ( fig.…”

Section: Discussionsupporting

confidence: 81%

“…The serum levels of both the estrogenic and the progestogenic com ponents achieved in the individual woman are depen dent on the dose administered and a number of pharma cokinetic parameters like bioavailability, distribution and clearance, which all show a considerably high intraand intersubject variability, especially in the case of EE2 [1], Until recently, there was no evidence available from clinical studies to suggest that the pharmacokinetics of EE2 could be altered due to interactions with a coadmin istered progestin. Some time ago, however, it was re ported in a comparative study that women who received a combination of gestodene and EE2 (75 pg/30 pg) showed higher serum levels of EE2 than women who received a combination of desogestrel and EE2 (150 pg/30 pg), despite the fact that the EE2 dose was the same in both formulations [2], Subsequent clinical stud ies have failed to confirm the observation of different EE2 levels [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Concentration of Ethinyl Estradiol in the Serum of 31 Young Women following a Treatment Period of 3 Months with Two Low-Dose Oral Contraceptives in an Intraindividual Cross-Over Design

Kuhnz¹,

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Power

et al. 1991

Horm Res

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Two low-dose oral contraceptives, both containing the same dose of ethinyl estradiol (EE₂) but different progestins (gestodene and desogestrel, respectively), were compared with respect to the relative bioavailability of EE₂. The study was conducted with 31 women as an open intraindividual comparison with the ingestion of both preparations for 3 months, respectively. On days 1,10 and 21 of the 1 st, 3rd and 6th cycle, blood was sampled at 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 10 and 24 h following administration. The concentrations of EE₂ were determined in the serum samples of each individual and the area under the serum concentration versus time curves, AUC (0–4 h) and AUC (0–24 h), were calculated. Corresponding parameters obtained on days 1,10 and 21 of the 3rd and 6th month of treatment were compared on a statistical basis, and no differences were found. This result was in concordance with a previously performed study, where both formulations were administered to 18 women in a single-dose cross-over design. However, the results of the previous and the present study are at variance with the result of one other study, reporting higher EE₂ levels in the serum of women taking the gestodene-containing formulation as compared to those taking the desogestrel-containing formulation.

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Section: Discussionsupporting

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Concentration of Ethinyl Estradiol in the Serum of 31 Young Women following a Treatment Period of 3 Months with Two Low-Dose Oral Contraceptives in an Intraindividual Cross-Over Design

Kuhnz¹,

Back

Power

et al. 1991

Horm Res

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“…Both, inter-and intraindividual coefficients of variation for parameters, such as AUC (0-24h), were found to be in the range 47-57% and 41-42%, respectively, which is consistent with the observations of others (BRODY et al 1989;GOLDZIEHER 1989;FOTHERBY 1991). It was also shown in a clinical study that, in spite of adhering to the most stringent inclusion and exclusion criteria, no substantial reduction in the interindividual variability could be achieved (STADEL et al 1980).…”

Section: Pharmacokinetics In Humanssupporting

confidence: 90%

“…1990). It has also been pointed out that due to the large interindividual variation in the pharmacokinetics of EE, plasma levels generated by 35 flg EE in one person may be indistinguishable from those produced by 50 flg in another (BRODY et al 1989). …”

Section: Absorptionmentioning

confidence: 98%

Pharmacokinetics of Exogenous Natural and Synthetic Estrogens and Antiestrogens

Kuhnz¹,

Blode²,

Zimmermann³

1993

Handbook of Experimental Pharmacology

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“…We divided the preparations that fell in the intermediate oestrogen potency category (in the pharmacy text) into high-and low-potency groups for this analysis. Oral contraceptive formulations with 35 mg ethinyl oestradiol or 50 mg mestranol were classified as high potency since these doses are approximately biologically equivalent (Brody et al, 1989). Those with less than 35 mg ethinyl oestradiol or 50 mg mestranol were classified as low potency.…”

Section: Defining Oral Contraceptive Formulation and Potencymentioning

confidence: 99%

Hormonal content and potency of oral contraceptives and breast cancer risk among young women

Althuis

Brogan²,

Coates

et al. 2003

Br J Cancer

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Recent use of oral contraceptive pills is associated with a modest risk of breast cancer among very young women. In this US population-based case -control study, we evaluated whether the excess risk associated with recent oral contraceptive use is ubiquitous for all pill types or attributable to specific oral contraceptive preparations. Hormonal content and potency of combination oral contraceptives used for the longest duration within 5 years of interview for breast cancer cases aged 20 -44 years (N ¼ 1640) were compared with age-matched community controls (N ¼ 1492). Women who recently used oral contraceptives containing more than 35 mg of ethinyl oestradiol per pill were at higher risk of breast cancer than users of lower dose preparations when compared to never users (respective relative risks of 1.99 and 1.27, P trend o0.01). This relationship was more marked among women o35 years of age, where risks associated with high-and low-dose ethinyl oestradiol use were 3.62 and 1.91 (P trend o0.01), respectively. We also found significant trends of increasing breast cancer risk for pills with higher progestin and oestrogen potencies (P trend o0.05), which were most pronounced among women aged o35 years of age (P trend o0.01). Risk was similar across recently used progestin types. Our findings suggest that newer low-potency/low oestrogen dose oral contraceptives may impart a lower risk of breast cancer than that associated with earlier high-potency/high-dose preparations.

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Pharmacokinetics of three bioequivalent norethindrone/mestranol-50ug and three norethindrone/ethinyl estradiol-35ug oc formulations: Are “low-dose” pills really lower?

Cited by 47 publications

References 13 publications

Concentration of Ethinyl Estradiol in the Serum of 31 Young Women following a Treatment Period of 3 Months with Two Low-Dose Oral Contraceptives in an Intraindividual Cross-Over Design

Concentration of Ethinyl Estradiol in the Serum of 31 Young Women following a Treatment Period of 3 Months with Two Low-Dose Oral Contraceptives in an Intraindividual Cross-Over Design

Pharmacokinetics of Exogenous Natural and Synthetic Estrogens and Antiestrogens

Hormonal content and potency of oral contraceptives and breast cancer risk among young women

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