Does St. John's wort interfere with the antiandrogenic effect of oral contraceptive pills?
BACKGROUND
St. John's wort (SJW), a commonly used herbal remedy, has been shown to compromise the efficacy of drugs, including oral contraceptive pills (OCPs), by inducing cytochrome P-450. We investigated whether the simultaneous use of SJW with OCPs resulted in elevated serum androgen levels with implications of impaired OCP treatment of hirsutism and acne.


METHODS
Fifteen healthy women were treated with the low-dose OC Loestrin 1/20trade mark for 2 months and then additionally with SJW for 2 months. Androgen and sex hormone-binding globulin (SHBG) levels were measured in serum by immunoassay methods; free testosterone (fT) was calculated. Results were analyzed using the Wilcoxon signed-rank test.


RESULTS
There were no statistically significant differences in androgen levels after the addition of SJW in women using Loestrin 1/20trade mark. However, there were decreases in total testosterone and fT levels (10.7% and 15.8%, respectively) along with a small increase in SHBG levels (7.0%).


CONCLUSIONS
In women using OCPs and SJW simultaneously, it appears that SJW does not interfere with the antiandrogenic properties of OCPs.
Fogle
Robin H
RH
Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Women's and Children's Hospital, University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA. robinfogel@yahoo.com
Murphy
Patricia A
PA
Westhoff
Carolyn L
CL
Stanczyk
Frank Z
FZ
D000152:Acne Vulgaris / Q000188:drug therapy; D000293:Adolescent; D000328:Adult; D000726:Androgen Antagonists / Q000494:pharmacology*; D000728:Androgens / Q000097:blood; D003276:Contraceptives, Oral / Q000037:antagonists & inhibitors* / Q000494:pharmacology / Q000627:therapeutic use; D004338:Drug Combinations; D004347:Drug Interactions; D004997:Ethinyl Estradiol / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D006628:Hirsutism / Q000188:drug therapy; D006801:Humans; D020902:Hypericum / Q000009:adverse effects*; D009640:Norethindrone / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D016037:Single-Blind Method; D013739:Testosterone / Q000097:blood
D000726:Androgen Antagonists; D000728:Androgens; D003276:Contraceptives, Oral; D004338:Drug Combinations; D012738:Sex Hormone-Binding Globulin; C020416:norethindrone acetate, ethinyl estradiol, ferrous fumarate drug combination; D013739:Testosterone; D004997:Ethinyl Estradiol; D009640:Norethindrone