Use of St. John's Wort in Potentially Dangerous Combinations

Abstract

Objectives:

The objective of this study was to assess how often St. John's wort (SJW) is prescribed with medications that may interact dangerously with it.

Design:

The study design was a retrospective analysis of nationally representative data from the National Ambulatory Medical Care Survey.

Settings:

The study setting was U.S. nonfederal outpatient physician offices.

Subjects:

Those prescribed SJW between 1993 and 2010 were the subjects.

Outcome Measures:

The outcome measures were medications co-prescribed with SJW.

Results:

Twenty-eight percent (28%) of SJW visits involved a drug that has potentially dangerous interaction with SJW. These included selective serotonin reuptake inhibitors, benzodiazepines, warfarin, statins, verapamil, digoxin, and oral contraceptives.

Conclusions:

SJW is frequently used in potentially dangerous combinations. Physicians should be aware of these common interactions and warn patients appropriately.