[Hypersensitivity to oral anticoagulants: report of a case].
We report a case regarding a 71 year-old Caucasian man with NYHA functional class III congestive heart failure, who was under warfarin treatment due to left ventricular thrombosis. After a few days, although the drug was not overdosed, the INR increased up to 11.68. Normal values were reestablished only after a 20-day pharmacological wash-out. Surprisingly, no episode of major or minor bleeding occurred. Gene typing of cytochrome P450 CYP2C9, a liver enzyme responsible for warfarin metabolism, showed that the patient was a carrier of both the mutant alleles (CYP2C9*2/*3) of this enzyme. This genetic defect caused a reduced catabolism of S-warfarin and excessive anticoagulation.
Patella
M M
MM
Dipartimento di Science Medico-Chirurgiche Cardiologiche, Respiratorie e Toraciche, Napoli.
Russo
P E
PE
De Lucia
D
D
Margaglione
M
M
Colaizzo
D
D
Iacono
A
A
D000284:Administration, Oral; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D004342:Drug Hypersensitivity / Q000209:etiology*; D006801:Humans; D008297:Male
D000925:Anticoagulants