Page 71 - 《中国药房》网络版 2018年6月第2期科普版

《中国药房》网络版 2018 年 6 月第 2 期科普版 Jun No.2 2018 China Pharmacy online Popular Science Edition

on the oral contraceptive alone, followed by 1 month of added St. John’s

wort 300 mg twice a day and then 1 month of added St. John’s wort 300

6
mg 3 times a day (hypericin content 0.3%). With the oral contraceptive
alone, 6 of the 17 women had breakthrough bleeding, but that increased

to 13 women with St John’s wort twice a day, and with St John’s wort

3 times a day, most of the women (15 of 17) had breakthrough bleeding.

CONCLUSION

The evidence suggests that St John’s wort taken with oral contraceptives

is likely to increase the risk of unin- tended pregnancy in at least some

women. The effect of St John’s wort on implants or other types of hormonal

contraceptives is not clear, but it would be prudent to assume that they

may interact as well. Women taking oral contraceptives should be advise

of the potential interaction with St John’s wort. Most would probably

choose to avoid St John’s wort, but if they decide it is necessary,
pharmacists could advised them about nonhormonal contraceptive methods

to replace oral contraceptives.

References

1. Choi S, Oh DS, Jerng UM. A systematic review of the pharmacokinetic

and pharmacodynamics interactions of herbal medicine with warfarin. PLoS

One. 2017;12(8):e0182794. doi: 10.1371/journal.pone.0182794.

2. Soleymani S, Bahramsoltani R, Rahimi R, Abdollahi M. Clinical risks

of St John’s wort (Hypericum perforatum) co-administration. Expert Opin

Drug Metab Toxicol. 2017;13(10):1047-1062. doi:

10.1080/17425255.2017.1378342.

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