MCQ of the Day

A  27 years old female was suffering from palpitations.  On echocardiography she was suffering from mitral regurgitation.  An artificial valve was placed.  She needs life long costeffective anticoagulation.  Which of the following agents is recommended in her case?

 

 

1. Aspirin
2. Debigatran
3. Rivaroxaban
4. Unfractionated Heparin
5. Vitamin K antagonist
    
    
    

 

 

 

 

 

 

 

 

Answer:e

Explanation:

Vitamin K antagonist i.e Warfarin is the traditional and cost effective long term anticoagulant used in these cases. A number of anticoagulants are available. The traditional ones are warfarin, other coumarins and heparins. There are a number of new agents  that are collectively called the novel oral anticoagulants (NOACs) or directly acting oral anticoagulants (DOACs). They include inhibitors of factor IIa (dabigatran) and factor Xa (rivaroxaban, apixaban and edoxaban).  They are possibly better than the coumarins with less serious side effects. They are more expensive than the traditional ones and should be used with care in patients with kidney diseasis. There is no antidote for the factor Xa inhibitors, so it is difficult to stop their effects in the body in cases of emergency (accidents, urgent surgery). Idarucizumab was FDA approved for the reversal of dabigatran.

 Debigatran and rivaroxaban are a lot costlier compared to warfarin, after having taken into consideration the cost of frequent blood testing associated with warfarin.

(Choice a) Aspirin can have added benefit but is not used for long term anticoagulation in cases of valvular surgery.

(Choice b) Explained

(Choice c) Explained

(Choice d) Unfractioned Heparin is not recommended for longterm anticoagulation.

 

Educational Objective: 

Warfarin is the drug of choice. Debigatran and rivaroxaban have a rapid onset action and relatively short half-lives.  They are more rapid and effective and allow for drugs to quickly reduce their anticoagulation effects. Routine monitoring and dose adjustments of Debigatran and rivaroxaban is less important than for warfarin, as they have better predictable anticoagulation activity. Both Debigatran and rivaroxaban  and warfarin are equivalent in effect, but Debigatran and rivaroxaban are less influenced by diet and medications compared to warfarin. There is  no antidote for most NOACs.