ICU · Pharmacology

Medication safety in ICU: prescribing errors, high-alert drugs, prevention, and drug interactions

Also known as Medication safety in ICU · Drug interactions in critical care · Pharmacovigilance in the ICU · Prescribing errors · High-alert medications · Therapeutic drug monitoring · Medication reconciliation · Computerised physician order entry · Barcode medication administration

Medication errors and adverse drug events are common and under-reported in the ICU — a systematic review found medication-error rates of 8.1 to 2344 per 1000 patient-days and adverse drug events of 5.1 to 87.5 per 1000 patient-days, varying widely with definitions and detection methods. Critically ill patients are uniquely vulnerable: 10-20+ concurrent drugs, altered pharmacokinetics (renal/hepatic dysfunction, augmented clearance, changed volume of distribution), organ support (ventilator, vasopressors, RRT), and restricted ability to report symptoms. Key interaction families: macrolides + statins (rhabdomyolysis), fluoroquinolones + QT-prolonging drugs (Torsades), warfarin + antibiotics (INR elevation/bleeding), linezolid + serotonergic drugs (serotonin syndrome), azoles + calcineurin inhibitors (CYP3A4 toxicity). High-alert medications (insulin, anticoagulants, opioids, sedatives, neuromuscular blockers, concentrated electrolytes, vasoactives) cause disproportionate harm when misused. Prevention is layered: computerised physician order entry (CPOE) with clinical decision support, barcode medication administration (BCMA), smart infusion pumps with drug libraries, standardised order sets and concentrations, tall man lettering, independent double-checks of high-alert drugs, pharmacist-led review and medication reconciliation, and therapeutic drug monitoring (vancomycin AUC-guided, aminoglycoside extended-interval, digoxin, antiepileptics).