Effects of an oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg dienogest on thyroid hormones and androgen parameters: conventional vs. extended-cycle use.
BACKGROUND
This study was conducted to investigate the effects of an oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg dienogest on thyroid hormones and androgen parameters.


METHODS
Thyroid and androgen parameters were measured in 59 women treated with a monophasic combined oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg dienogest (EE/DNG) either conventionally (13 cycles with 21 days of treatment+7 days without hormones) or according to an extended-cycle regimen (four extended cycles with 84 days of continuous administration of EE/DNG, followed by a hormone-free interval of 7 days). Blood samples were taken on Days 21-26 of the preceding control cycle and on Days 19-21 of the 3rd and 13th conventional cycle, or on Days 82-84 of the first and fourth extended cycle.


RESULTS
At both time points, the serum concentrations of thyroxine-binding globulin were elevated by about 65% in both treatment regimens. Likewise, both groups showed an increase in total triiodothyronine (T3) and total thyroxine (T4) by 30-40%, and no change in free T4. Until the 12th month of conventional treatment, the level of free T3 remained unchanged but decreased slightly during the extended-cycle regimen. In both groups there was a rise of sex hormone-binding globulin by 210-230% after 3 months and by 220-250% after 12 months. The levels of total testosterone were reduced by about 40% and those of free testosterone by 55-65% after 3 and 12 months.


CONCLUSIONS
The results suggest that, during conventional and extended-cycle treatment with EE/DNG, a steady state in the effects on thyroid hormones and androgen parameters was reached within 3 months and that the changes in the various hormonal parameters did not substantially differ between conventional and extended-cycle regimen.
Sänger
Nicole
N
Center of Obstetrics and Gynecology, University Hospital of Frankfurt, Germany.
Stahlberg
Skadi
S
Manthey
Torsten
T
Mittmann
Katrin
K
Mellinger
Uwe
U
Lange
Evelyn
E
Kuhl
Herbert
H
Wiegratz
Inka
I
D000328:Adult; D000728:Androgens / Q000378:metabolism*; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004334:Drug Administration Schedule; D004967:Estrogens / Q000008:administration & dosage / Q000493:pharmacokinetics; D004997:Ethinyl Estradiol / Q000008:administration & dosage* / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D009277:Nandrolone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D011446:Prospective Studies; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013739:Testosterone / Q000097:blood; D013963:Thyroid Hormones / Q000378:metabolism*; D013975:Thyroxine-Binding Proteins / Q000378:metabolism
D000728:Androgens; D003277:Contraceptives, Oral, Combined; D004967:Estrogens; D012738:Sex Hormone-Binding Globulin; D013963:Thyroid Hormones; D013975:Thyroxine-Binding Proteins; D013739:Testosterone; D004997:Ethinyl Estradiol; C023635:dienogest; D009277:Nandrolone