title: Warfarin, St John's wort and INR.
authors.affiliation: Clinical pharmacists, Lismore Base Hospital, Lismore, NSW.
authors.forename: Angela
authors.initials: A
authors.lastname: Cattanach
authors.affiliation: Clinical pharmacists, Lismore Base Hospital, Lismore, NSW.
authors.forename: Siboniso
authors.initials: S
authors.lastname: Sibindi
keywords: Hypericum perforatum extract; international normalised ratio; warfarin