MRC-ICU score = 3 × number of 3-point items + 2 × number of 2-point items + number of 1-point items + parenteral-nutrition points.

Weight	Medication or support items
3 points each	Aminoglycosides; anticonvulsants; active inpatient chemotherapy; clozapine; digoxin; immunosuppressants; lithium; theophylline; intravenous vancomycin; warfarin.
2 points each	Argatroban; systemic azole antifungals; factor products or antithrombin III; continuous lidocaine; prostacyclins; therapeutic-dose heparins; neuromuscular blockade; continuous opioid or sedative infusions; each restricted antimicrobial or high-acuity device counted in the 2-point bundle (dialysis or continuous renal replacement therapy, extracorporeal membrane oxygenation, or mechanical ventilation).
1 point each	Amphotericin B; antiarrhythmics; direct oral anticoagulants or fondaparinux; ganciclovir or valganciclovir; hyperosmolar fluids; other continuous infusions; each prophylaxis or device component counted in the 1-point bundle (VTE prophylaxis, stress-ulcer prophylaxis, subcutaneous insulin, bowel regimen, chlorhexidine, intra-aortic balloon pump, or LVAD); scheduled or PRN opioids or sedatives; other systemic antimicrobials.
Parenteral nutrition	0 points if none; 1 point when managed by a non-pharmacist service; 3 points when managed by a clinical specialist pharmacist.

There is no fixed maximum score.

Medication Regimen Complexity–ICU (MRC-ICU) Score (39-item version)