Background A growing body of evidence suggests that proton pump inhibitors (PPIs) may adversely interact with clopidogrel, diminishing the antiplatelet effect. The potential for increased risk of thrombotic complications warrants cautious use of this drug combination. When concomitant clopidogrel and PPI treatment is considered necessary, pantoprazole or ranitidine may offer a safe choice.

Purpose To analyse the prescription profile and financial impact of an alert that was added to the assisted electronic prescription program (EPP) and is triggered by a prescription for concomitant clopidogrel and omeprazole treatment. A safer choice that is pantoprazole or ranitidine is suggested to assist health professionals.

Materials and methods Retrospective cohort study. Period A (before this alert was added) April–June 2010: pantoprazole was the only PPI included in the hospital's formulary and Period B (after this alert was introduced) April–June 2011: omeprazole and pantoprazole as the low cost and the alternative options respectively for prescribing PPIs. The authors looked at all the clopidogrel prescriptions in both periods of study. Patient code, age (years), gastric protector drug (none, omeprazole, pantoprazole, ranitidine), dose (mg/day) and treatment cost/day data were collected from the EPP. Main outcome and measures: number of patient with PPIs as the treatment for gastric protection and average treatment cost/day. Statistical analysis: OR with its 95% CI and t-test were used to compare the two periods.

Results A total of 360 patients were included in Period A (70% men) with a mean age of 72.2 (IC 95% 70.8 to 73.5) and 327 in Period B (68.9% men) with a mean age of 72.5 (IC 95% 71.2 to 73.8). The change from Period A to Period B was: the percentage of patients treated with a PPI fell from 68.9% to 24.7% (OR=0.15; IC 95% 0.11 to 0.21; p<0.05); the percentage of these patients treated with ranitidine rose from (26.1% to 65.7% OR=5.43; IC 95% 3.91 to 7.54; p<0.05). In Period B physicians ignored the alert in 11.6% of patients. Average cost/day per patient was higher in Period A: 0.21 (IC 95% 0.20 to 0.22) versus 0.05 (IC 95% 0.04 to 0.07; p<0.05)

Conclusions The prescription profile for PPIs was modified by the introduction of the alert. Fewer patients taking clopidogrel are now being prescribed a PPI and a safer drug is used more often. The cost per patient is now lower.