Drug interaction checking

Why it matters

Prescribing is where most preventable medication harm begins. A meta analysis of 81 studies in BMC Medicine found the highest share of preventable harm at the prescribing stage (58%) and at monitoring (47%) [1]. Interaction checking places a known safeguard at the moment of prescribing and repeats it when the pharmacist verifies the order.

Key points

• Checks run at order entry and again at verification. AHRQ PSNet describes clinical pharmacists checking for interactions and allergies before medication is released [2].
• Severity grading keeps serious interactions visible. A check that flags every minor interaction trains clinicians to dismiss alerts.
• Allergy checking uses the same mechanism against the allergies recorded for the patient, so the quality of allergy documentation sets the limit of what the check can catch.
• Explicit prescribing tools add value in high risk groups: a systematic review found that trials of tools such as STOPP/START showed clinical and economic impact in geriatric and internal medicine settings [3].
• An override should require a reason and be recorded for review.

In Moana

MOANA Pharmacy checks interactions and allergies with severity when a medicine is prescribed and again at pharmacist verification. Clinical rules raise the flag; the prescriber and the pharmacist review every flag.

Sources

1. Preventable medication harm across health care settings: a systematic review and meta analysis, BMC Medicine, 2020
2. Medication errors and adverse drug events: PSNet primer, Agency for Healthcare Research and Quality, accessed 2026
3. Clinical and economic impacts of explicit tools detecting prescribing errors: a systematic review, Agency for Healthcare Research and Quality, summarising the Journal of Clinical Pharmacy and Therapeutics, 2021