What do systematic reviews say?

Antacids vs placebo or no prophylaxis

Antacids showed no clear difference in number of participants requiring blood transfusions compared with placebo or no prophylaxis (low certainty).

• Interventions for preventing upper gastrointestinal bleeding in people admitted to intensive care units 2018 · Cochrane Headline outcomes only
  RR 0.94 [0.3, 2.96]
  2 studies · 226 participants
  Low