The enzyme CYP2B6 (full name: Cytochrome P450 2B6) is involved in the metabolisation of xenobiotics, such as drugs. Around 5-10% of all drugs are metabolised in part by CYP2B6.
Drugs that can be metabolised by the enzyme CYP2B6 include:
- Antidepressants such as bupropion
- Antiviral drugs such as efavirenz and nevirapine
- Painkillers such as ketamine and methadone
- Cytostatics such as cyclophosphamide and ifosfamide
At present no specific dosing adjustments have been described on the basis of CYP2B6 genotyping.
Efavirenz and the enzyme CYP2B6
Efavirenz is processed within the body primarily by the enzyme CYP2B6. The activity of this enzyme can vary considerably depending on your genetic predisposition, which means the efficacy of efavirenz and the risk of side effects can also differ from person to person.
Information about your genetic predisposition may therefore provide grounds for extra vigilance in relation to a treatment with efavirenz.
Read more about Efavirenz »
The activity of the enzyme CYP2B6 varies from one individual to another.
As a result, the efficacy of a drug can differ from person to person, as can the risk of potential side effects. This variation can be partly explained by genetic variations in the CYP2B6 gene.
When a genotype is determined these variations in the CYP2B6 gene are indicated by two so-called alleles. Each allele has a name consisting of an asterisk (*) and a number. An example of a possible CYP2B6 genotype is CYP2B6*1/*4.
At iGene we determine the following variants (alleles) of the CYP2B6 gene:
CYP2B6*4, CYP2B6*5, CYP2B6*6, CYP2B6*7, CYP2B6*8, CYP2B6*12, CYP2B6*16, CYP2B6*18, CYP2B6*24, CYP2B6*28 and other (classified as CYP2B6*1).