With barbiturates, an interaction with anticoagulants often results in what effect?

• A. The anticoagulant is less effective due to this medication.
• B. The anticoagulant becomes more effective.
• C. Platelet count increases.
• D. No interaction occurs.

Answer: (A)

Barbiturates act as enzyme inducers in the liver, speeding up the metabolism of many drugs, including anticoagulants like warfarin. When their metabolism is increased, the anticoagulant’s blood levels fall, reducing its ability to prevent clotting. So the anticoagulant becomes less effective due to this medication. This interaction does not increase the anticoagulant’s effect, does not raise platelet counts, and there is indeed an interaction to consider.