Poll 4: Latent Errors and Systems Failures

After your colleague spent a difficult night on call, she paged you to discuss an awkward situation. You had seen an elderly patient in the office a week earlier and prescribed a diuretic for mild hypertension. Two days later, the patient was seen by another physician in the office and started on ibuprofen for mechanical back pain. The patient was admitted overnight with acute renal failure, attributed to the combination of diuretic and non-steroidal anti-inflammatory medication.

What factor do you think were the most important contributor to this adverse drug event?