Acenocoumarol - Sintrom

CYP2C9

Variant

Alleles

Activity

Wild type
430C>T
1075A>C
1076T>C
1080C>G
818delA

*1
*2
*3
*4
*5
*6

Normal
Decr.
Decr.
Decr.
Decr.
Null

VKORC1

Variant

Activity

Wild type
-1639G>A

Normal
Acenocoumarol sensitive

EM – IM – PM – UM

CYP2C9 Prevalences in Caucasian

Extensive metabolizers (EM) represent the norm for metabolic capacity. Genotypes consistent with the EM phenotype include two active forms of the gene producing the drug metabolizing enzyme and therefore posses the full complement of drug metabolizing capacity. Generally, extensive metabolizers can be administered drugs which are substrates of the enzyme following standard dosing practices.

67%

Intermediate metabolizers (IM) may require lower than average drug dosages for optimal therapeutic response. In addition, multiple drug therapy should be monitored closely.

30%

Poor metabolizers (PM) are at increased risk of drug-induced side effects due to diminished drug elimination or lack of therapeutic effect resulting from failure to generate the active form of the drug. Genotypes consistent with the PM phenotype are those with no active genes producing the drug metabolizing enzyme. These individuals have a deficiency in drug metabolism.

3%

Ultra-extensive metabolizers (UM) may require an increased dosage due to higher than normal rates of drug metabolism. Simultaneously treating with medication that inhibits metabolization has also proven effective. Genotypes consistent with UM phenotype include three or more active genes producing the drug metabolizing enzyme and therefore have increased metabolic capacity.

0%