Comparison of vaginal and oral administration of emergency contraception.
OBJECTIVE
To compare the physiologic effects of vaginally and orally administered emergency contraception.


METHODS
Prospective, open-label, crossover study.


METHODS
University research center.


METHODS
Nine regularly menstruating volunteers.


METHODS
Five subjects received 1,000 microg of levonorgestrel with 200 microg of ethinyl E2 (twice the standard Yuzpe regimen dose) vaginally, and the standard Yuzpe regimen dose orally 1 week later. Four subjects received 1,500 microg of levonorgestrel (twice the standard Plan B regimen dose) vaginally and received the standard Plan B dose orally 1 week later. Serum samples were obtained at baseline and at frequent intervals after each dose.


METHODS
Serum gonadotropin, hepatic globulin, and androgen levels measured at baseline, at the time of peak levonorgestrel, and 24 hours later.


RESULTS
Gonadotropin, hepatic globulin, and androgen levels were suppressed to a similar degree among the four regimens, with a return to baseline levels after 24 hours.


CONCLUSIONS
We conclude that high doses of levonorgestrel found in emergency contraception regimens lead to a transient direct suppression of gonadotropin, hepatic globulin, and androgen levels. This effect is similar after vaginal and oral administration of emergency contraception. Therefore, the vaginal route of administration of emergency contraception regimens may be as efficacious as the oral route.
Mor
Eliran
E
Department of Obstetrics and Gynecology, University of Southern California Keck School of Medicine, Los Angeles, California, USA. eliranmor@hotmail.com
Saadat
Peyman
P
Kives
Sari
S
White
Emily
E
Reid
Robert L
RL
Paulson
Richard J
RJ
Stanczyk
Frank Z
FZ
D000282:Administration, Intravaginal; D000284:Administration, Oral; D000328:Adult; D003280:Contraceptives, Oral, Synthetic / Q000008:administration & dosage; D003283:Contraceptives, Postcoital, Synthetic / Q000008:administration & dosage*; D018592:Cross-Over Studies; D004997:Ethinyl Estradiol / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D016912:Levonorgestrel / Q000008:administration & dosage*; D011446:Prospective Studies; D014621:Vagina / Q000187:drug effects* / Q000378:metabolism
D003280:Contraceptives, Oral, Synthetic; D003283:Contraceptives, Postcoital, Synthetic; D004997:Ethinyl Estradiol; D016912:Levonorgestrel