Nature and frequency of drug therapy alerts generated by clinical decision support in community pharmacy.

PURPOSE: The purpose of this study is to investigate the nature, frequency, and determinants of drug therapy alerts generated by a clinical decision support system (CDSS) in community pharmacy in order to propose CDSS improvement strategies. METHODS: This is a retrospective analysis of dispensed drugs and drug therapy alerts generated by a CDSS in community pharmacies. RESULTS: Data were extracted from the CDSS of 123 community pharmacies. After taking a 10% random sample of patients with a prescription in the period August 2013-July 2014, 1,672,169 dispensed prescriptions from 81,742 patients were included in the analysis. Of all processed prescriptions, 43% led to one or more drug safety alerts, most frequently drug-drug interaction alerts (15% of all prescriptions), drug-disease interaction alerts (14%), duplicate medication alerts (13%), and dosing alerts (7%). The majority of prescriptions with alerts (80%) were clustered in a minority of patients (16%). The therapeutic drug group of the prescribed drug was the most important determinant of alert generation. Prescriptions for antithrombotic agents accounted for 9.4% of all prescriptions with an alert, beta-blocking agents for 7.5% and angiotensin-converting-enzyme inhibitors for 6.1%. DISCUSSION AND CONCLUSION: The investigated CDSS in Dutch community pharmacy generated one or more drug therapy alerts in nearly half of the processed prescriptions. The majority of alerts were concentrated in a minority of therapeutic drug groups and patients. To decrease the alert burden, CDSS improvements should be directed at the prioritization and integration of drug therapy alerts for these therapeutic groups within patients.

NSAID-antihypertensive drug interactions: which outpatients are at risk for a rise in systolic blood pressure?

BACKGROUND: Management guidelines for drug-drug interactions between non-steroidal anti-inflammatory drugs (NSAIDs) and antihypertensives recommend blood pressure monitoring in hypertensive patients. We measured the short-term effect of initiating NSAIDs on systolic blood pressure (SBP) in users of antihypertensives, aiming to investigate which outpatients are at risk for an increase in SBP in daily clinical practice. DESIGN: A cohort study with a nested case-control design in Dutch community pharmacies. METHODS: Patients with a drug-drug interaction alert for a newly initiated NSAID and antihypertensive were interviewed and their SBP was measured at T0, after one week (T1) and after two weeks (T2). We evaluated risk factors for exceeding a predefined limit of change (PLoC) in SBP (≥ 10 mmHg to ≥ 140 mmHg) at T1 and T2 versus T0. RESULTS: For 112 patients the SBP at T0 was measured. Two patients were excluded (T0 SBP ≥ 180 mmHg). PLoC was exceeded in 10 patients (10.4%) at T1 and in seven patients (8.0%) at T2. Patients using etoricoxib (odds ratio (OR), 21.0; 95% confidence interval (CI), 3.7-120.6) and patients using >1 defined daily dose of an NSAID (OR, 3.3; 95% CI, 1.1-10.0) were at increased risk of a rise in SBP. CONCLUSIONS: A newly initiated NSAID has an immediate clinically relevant effect on SBP in some users of antihypertensives. Management guidelines for NSAID-antihypertensive drug-drug interactions should advise SBP monitoring before and after initiation of an NSAID or intensification of NSAID therapy. Monitoring is especially relevant in patients prescribed high dosages of NSAIDs. Etoricoxib should not be used in hypertensive patients.