Drug interaction between oral contraceptives and St. John's Wort: appropriateness of advice received from community pharmacists and health food store clerks.
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).


METHODS
Cross-sectional study.


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


METHODS
Community pharmacists (n=99) and health food store clerks (n=84).


METHODS
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?"


METHODS
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%; Xchi(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; Xchi(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).


CONCLUSIONS
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.
Sarino
Lord V
LV
School of Pharmacy, University of California-San Francisco, CA 94143-0622, USA.
Dang
Kristy H
KH
Dianat
Nahal
N
Djihanian
Hera
H
Natanian
Neda
N
Hudmon
Karen Suchanek
KS
Ambrose
Peter J
PJ
D002140:California; D003276:Contraceptives, Oral / Q000009:adverse effects*; D019587:Dietary Supplements / Q000009:adverse effects*; D004347:Drug Interactions; D058870:Food, Organic; D006801:Humans; D020902:Hypericum / Q000009:adverse effects*; D010594:Pharmacies; D010595:Pharmacists
D003276:Contraceptives, Oral