Question

A CYP2C19 poor metabolizer patient on clopidogrel while also on lansoprazole therapy. this patient:

A) will have a CYP2C19*1/CYP2C19*2 genotype

B) should be considered for prasugrel therapy

C) will have a high concentration of the drug active metabolite

D) should be considered for increased clopidgrel doses

Answer 1

Clopidogrel is an anti-platelet drug which is an ADP inhibitor. It is a prodrug and requires activation by the enzyme CYP2C19. This enzyme converts clopidogrel into its active metabolite. This enzyme is inhibited by the lansoprazole. Therefore, clopidogrel cannot be combined with lansoprazole as it reduces its conversion into active metabolite.

A	wrong	*1/*2 genotype means intermediate metabolizer. As the patient is poor metabolizer, he may have*2/*2, *2/*3 or *3/*3.
B	right	Prasugrel is derivative of clopidogrel. It is not a prodrug. It doesn't require activation by enzyme CYP2C19. Therefore it can be given in this patient.
C	wrong	Wrong. He would have further decreased concentration of active metabolite.
D	wrong	Clopidogrel in Increased doses will not do any work as the patient is already a poor metabolizer and also getting lansoprazole along with.