Rob MacLaren, BSc, PharmD, MPH, MCCM, FCCP, is a critical care pharmacist and professor at the University of Colorado Skaggs School of Pharmacy, renowned for his expertise in stress ulcer prophylaxis guidelines. He discusses the evolving landscape of stress ulcer prevention, including risk factors for critically ill patients and the distinction between H2RA and PPI treatments. Key studies, such as the REVISE trial, are examined for their impact on guidelines. MacLaren also emphasizes the importance of a targeted, evidence-based approach, raising critical questions about blanket medication use in ICUs.