ON DEMAND THERAPY FOR HEARTBURN-DOMINANT UNINVESTIGATED DYSPEPSIA (HBDUD) IN PRIMARY CARE PRACTICE (PCP): THE CADET-HR STUDY

D Armstrong¹, AN Barkun², N Chiba¹, S Veldhuyzen van Zanten³, ABR Thomson⁴, SL Smyth⁵, B Chakraborty⁵, P Sinclair⁶ and CADET-HR Investigators

¹McMaster University, Hamilton, Ontario; ²McGill University, Montreal, Quebec; ³Dalhousie University, Halifax, Nova Scotia; ⁴University of Alberta, Edmonton, Alberta; ⁵AstraZeneca Canada, Mississauga, Ontario; ⁶INSINConsulting, Guelph, Ontario

AIM: To compare omeprazole (O) and ranitidine (R) 'on demand' therapy over 6-months in HBDUD patients whose symptoms had relapsed after initial, successful stepped acid antisecretory therapy ('Start PPI' - O: 20 mg od to O: 40 mg od vs. 'Start H²RA' - R: 150 mg bid to O: 20 mg od).
METHODS: A 6-month, double-blind, single-dummy RCT conducted at 46 Canadian PCPs. Inclusion: recurrent moderate-to-severe HB, score ³4 on ³2 days within a 7-day period. Patients kept a daily symptom diary and drug use was monitored monthly; data are presented as mean±SD.
RESULTS: 220 patients were randomised (O: 106, R: 114). By 6 months, the proportions (95% CI) of patients unwilling to continue were overall: O: 17.9% (10.6-25.2) and R: 21.1% (13.6-28.5) (p>0.05) and due to HB: O: 5.7% (1.3-10.1) and R: 15.8% (9.1-22.5) (p=0.02). The median proportions (95% CI) of symptom free days were: O: 47.8% (35.9-60.0) and R: 18.5% (8.8-28.5) (p < 0.001). HB symptom score in the 7 days before baseline and at 8, 16, and 24 Weeks were respectively: O: 3.8±1.1, 2.2±1.0*, 2.1±0.9, 2.1±1.2*, and R: 3.7±0.8, 2.8±1.1, 2.4±1.1, 2.5±1.2 (*p<0.05 O vs R). The mean daily tablet intake was - active + placebo: O: 0.81±0.59; R: 1.16±0.63 (p<0.001), and active only: O: 0.55±0.34; R: 1.16±0.63 (p<0.001).
CONCLUSIONS: 'On demand' therapy with O is superior to R for symptom relief, the proportion of patients willing to continue due to heartburn control, and the number of tablets taken. Thus, this therapy with O is an effective strategy for symptom control in primary care practice patients with heartburn-dominant uninvestigated dyspepsia.

This study was financially supported by AstraZeneca Canada.