The Pharmaceutical Journal
Vol 269 No 7216 p423
21 September 2002

Society summary

Information sheet highlights interactions with St John's wort

The Royal Pharmaceutical Society has published an information sheet for pharmacists about interactions between St John's wort and various prescription medicines. Copies are being distributed to community and hospital pharmacists with this week's issue of The Journal.

The leaflet says that although St John's wort (Hypericum perforatum) may be effective in treating mild-to-moderate depression, it may reduce the therapeutic effects of warfarin, ciclosporin, digoxin, theophylline and anticonvulsants, increase the serotonergic effects of triptans and selective serotonin reuptake inhibitors, and lead to breakthrough bleeding or unintended pregnancy in women taking oral contraceptives. It may also affect HIV suppression in patients treated with protease inhibitors or non-nucleoside reverse transcriptase inhibitors,

The information sheet advises pharmacists to counsel patients appropriately and report any adverse reactions through the yellow card scheme.

The leaflet, entitled "Herb–medicine interactions: St John's wort", has been produced as part of the Society's "Scientist in the high street" campaign, which is designed to raise the public profile of the community pharmacist as a scientist. It was written by Dr Jo Barnes, MRPharmS, of the School of Pharmacy, University of London, with assistance from members of the Society's working group on complementary medicines.

Dr Nicola Gray, chairman of the Society's Science Committee, said that the information sheet highlights yet again how pharmacists can increase patient safety by offering professional advice that reflects the public's interest in both conventional and alternative remedies.

The information sheet is also available from the science section of the Society's website at www.rpsgb.org.uk/science or by telephoning 020 7572 2261.