title: Study of natural health product adverse reactions (SONAR): active surveillance of adverse events following concurrent natural health product and prescription drug use in community pharmacies.
abstract: BACKGROUND
  Many consumers use natural health products (NHPs) concurrently with prescription medications. As NHP-related harms are under-reported through passive surveillance, the safety of concurrent NHP-drug use remains unknown. To conduct active surveillance in participating community pharmacies to identify adverse events related to concurrent NHP-prescription drug use.
  
  
  RESULTS
  Participating pharmacists asked individuals collecting prescription medications about (i) concurrent NHP/drug use in the previous three months and (ii) experiences of adverse events. If an adverse event was identified and if the patient provided written consent, a research pharmacist conducted a guided telephone interview to gather additional information after obtaining additional verbal consent and documenting so within the interview form. Over a total of 112 pharmacy weeks, 2615 patients were screened, of which 1037 (39.7%; 95% CI: 37.8% to 41.5%) reported concurrent NHP and prescription medication use. A total of 77 patients reported a possible AE (2.94%; 95% CI: 2.4% to 3.7%), which represents 7.4% of those using NHPs and prescription medications concurrently (95%CI: 6.0% to 9.2%). Of 15 patients available for an interview, 4 (26.7%: 95% CI: 4.3% to 49.0%) reported an AE that was determined to be "probably" due to NHP use.
  
  
  CONCLUSIONS
  Active surveillance markedly improves identification and reporting of adverse events associated with concurrent NHP-drug use. Although not without challenges, active surveillance is feasible and can generate adverse event data of sufficient quality to allow for meaningful adjudication to assess potential harms.
authors.affiliation: Complementary and Alternative Research Program (CARE) for Integrative Health and Healing, Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada. CARE@med.ualberta.ca
authors.forename: Sunita
authors.initials: S
authors.lastname: Vohra
authors.forename: Kosta
authors.initials: K
authors.lastname: Cvijovic
authors.forename: Heather
authors.initials: H
authors.lastname: Boon
authors.forename: Brian C
authors.initials: BC
authors.lastname: Foster
authors.forename: Walter
authors.initials: W
authors.lastname: Jaeger
authors.forename: Don
authors.initials: D
authors.lastname: LeGatt
authors.forename: George
authors.initials: G
authors.lastname: Cembrowski
authors.forename: Mano
authors.initials: M
authors.lastname: Murty
authors.forename: Ross T
authors.initials: RT
authors.lastname: Tsuyuki
authors.forename: Joanne
authors.initials: J
authors.lastname: Barnes
authors.forename: Theresa L
authors.initials: TL
authors.lastname: Charrois
authors.forename: John T
authors.initials: JT
authors.lastname: Arnason
authors.forename: Candace
authors.initials: C
authors.lastname: Necyk
authors.forename: Mark
authors.initials: M
authors.lastname: Ware
authors.forename: Rhonda J
authors.initials: RJ
authors.lastname: Rosychuk
mesh_terms: D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems / Q000706:statistics & numerical data*; D000368:Aged; D001688:Biological Products / Q000009:adverse effects*; D002170:Canada; D005260:Female; D041743:Herb-Drug Interactions; D006801:Humans; D008297:Male; D008875:Middle Aged; D010594:Pharmacies; D010595:Pharmacists; D055553:Prescription Drugs / Q000009:adverse effects*; D062486:Public Health Surveillance; D011795:Surveys and Questionnaires
chemical_list: D001688:Biological Products; D055553:Prescription Drugs