Which statement about DOACs versus warfarin is NOT true?

• A. DOACs require routine INR monitoring
• B. DOACs have fewer drug interactions
• C. DOACs have no dietary considerations
• D. DOACs have predictable pharmacodynamics

Answer: (A)

DOACs do not require routine INR monitoring, which is the key point being tested. Unlike warfarin, which needs regular INR checks to ensure the dose keeps the patient in the therapeutic window (due to variable metabolism, diet, and many drug interactions), DOACs are given in fixed doses with more predictable effects. This makes routine lab monitoring unnecessary for anticoagulation level, though kidney function and other clinical factors should still be monitored because they can affect DOAC levels.

The other statements align with how DOACs are typically viewed: they generally have fewer drug interactions than warfarin, they leave dietary vitamin K considerations behind, and their effects are more predictable pharmacokinetically and pharmacodynamically.