Drug interaction between oral contraceptives and St. John's wort: Appropriateness of advice received from community pharmacists and health food store clerks
Lord V. Sarino, PharmD; Kristy H. Dang, PharmD; Nahal Dianat, PharmD; Hera Djihanian, PharmD; Neda Natanian, PharmD; Karen Suchanek Hudmon, DrPH, MS, BPharm; Peter J. Ambrose, PharmD, FASHP
J Am Pharm Assoc (2003) 2007;47:42-47. doi:10.1331/1544-3191.47.1.42.Sarino


Objective  To estimate the extent to which community pharmacists and health food store clerks provide appropriate advice regarding a drug interaction between oral contraceptives and St. John's wort (SJW).

Design  Cross-sectional study.

Setting  Three community pharmacy chains and three health food store chains in four highly populated counties in California.

Participants  Community pharmacists (n = 99) and health food store clerks (n = 184).

Intervention  Investigators, posing as consumers, telephoned pharmacists and health food store clerks and asked the following question: “Is there a problem with taking SJW with birth control pills?”

Main outcome measures  Respondents were classified based on their ability to correctly identify the drug interaction (yes or no) and on the overall appropriateness (i.e., the absence of incorrect advice) of their advice. Comparisons were made between men and women respondents and between pharmacists and health food store clerks.

Results  Community pharmacists were more likely than health food store clerks to correctly identify the drug interaction (50.5% versus 10.9%; χ2(1 df) = 54.32, P < 0.001). Overall, 31.8% of respondents provided inappropriate advice that implied the absence of a drug interaction (26.3% of 99 pharmacists and 34.8% of 184 health food store clerks; χ2(1 df) = 2.15, P = 0.14). Appropriateness of advice varied significantly among the three pharmacy chains (P < 0.001) and the three health food store chains (P < 0.05). Responses did not differ by gender of respondents (P = 0.18).

Conclusion  Lack of awareness of the potentially serious drug interaction between SJW and oral contraceptives by those who sell these products places the public at risk. Training and education, more comprehensive product labeling, and policies to refer consumers to drug information centers are needed.

Sign In
APhA Members 
Welcome to JAPhA.org! Please log in below using your APhA username and password. Update your APhA profile.
Not a Subscriber
New to JAPhA? Become an APhA member to receive a full subscription to both the print and online editions.


Register for a FREE limited account to benefit from personalization features such as alerts.


Henderson L, Yue QY, Bergquist C, et al. St. John's wort (Hypericum perforatum): drug interactions and clinical outcomes.  Br J Clin Pharmacol.  2002;54:349–56.[PubMed][CrossRef]
Linde K, Ramirez G, Mulrow CD, et al. St. John's wort for depression: an overview and meta-analysis of randomised clinical trials.  BMJ.  1996;313:253–8.[PubMed]
Anonymous. St. John's wort. In: Jellin JM, ed.  Natural Medicines Comprehensive Database.7th ed. Stockton, Calif.:  Therapeutic Research Faculty;  2005:1167–74.
Zhou S, Chan E, Pan SQ, et al. Pharmacokinetic interactions of drugs with St John's wort.  J Psychopharmacol.  2004;18:262–76.[PubMed]
Bailey DG, Dresser GK.  Natural products and adverse drug interactions.  CMAJ.  2004;170:1531–2.[PubMed]
Schwarz UI, Buschel B, Kirch W. Unwanted pregnancy on self-medication with St. John's wort despite hormonal contraception.  Br J Clin Pharmacol.  2003;55:112–3.[PubMed]
Hall SD, Wang Z, Huang S, et al. The interaction between St. John's wort and an oral contraceptive.  Clin Pharmacol Ther.  2003;74:525–35.[PubMed]
Pfrunder A, Schiesser M, Gerber S, et al. Interaction of St. John's wort with low-dose oral contraceptive therapy: a randomized controlled trial.  Br J Clin Pharmacol.  2003;56:683–90.[PubMed]
Murphy PA.  St. John's wort and oral contraceptives: reasons for concern? J Midwifery Women's Health.  2002;47:447–50.
Hindmarch M, Oakeshott P. Interactions of the oral contraceptive pill with antibiotics and St. John's Wort: knowledge of female college students.  Fam Pract.  2002;19:708.[PubMed]
Welna EM, Hadsall RS, Schommer JC.  Pharmacists' personal use, professional practice behaviors, and perceptions regarding herbal and other natural products.  J Am Pharm Assoc.  2003;43:602–11.
Brown CM, Barner JC, Sonalee S. Community pharmacists' actions when patients use complementary and alternative therapies with medications.  J Am Pharm Assoc.  2005;45:41–7.
Nathan JP, Cicero LA, Koumis T, et al. Availability of and attitudes toward resources on alternative medicine products in the community pharmacy setting.  J Am Pharm Assoc.  2005;45:734–9.
 Yasmin [package insert]. Montville, N.J., Berlex Inc;  2005.
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).
Please read the other comments before you post yours. Comments are moderated and will appear on the site at the discertion of the editorial staff.
* = Required Field
(if multiple authors, separate names by comma)
Example: John Doe

Related Content

Customize your page view by dragging & repositioning the boxes below.

JAPhA Articles
Topic Collections
PubMed Articles
  • Print
  • PDF Download
  • Email
  • Share
  • Get Citation
  • Submit Comment
  • Article Alerts
    Please Wait... Processing your request... Please Wait.
    You must sign in to sign-up for alerts.

    Please confirm that your email address is correct, so you can successfully receive this alert.

  • Letters To Editor
  • Reprints