What does it mean to be a CYP2D6 poor metabolizer?
What does it mean to be a CYP2D6 poor metabolizer?
Patientswho are poor metabolizers (individuals with no CYP2D6 activity) or ultrarapid metabolizers (individuals with genetically elevated CYP2D6 activity) can have markedly altered response to drugs that are CYP2D6 substrates. Note that ethnic differences exist in CYP2D6 activity.
What happens if you are a poor metabolizer?
Poor metabolizers – People in this group have little or no active CYP2D6 enzyme. People who are poor metabolizers break down some medicines slowly and are likely to need altered doses or even a different medicine in some cases.
How do you know if you are a poor metabolizer?
Poor metabolizers have significantly reduced or non-functional enzyme activity. Intermediate metabolizers have low or reduced enzyme activity. Extensive metabolizers have normal enzyme activity. Rapid or ultra-rapid metabolizers have high enzyme activity.
What medications are metabolized by CYP2D6?
Multiple tricyclic antidepressants, β blockers, haloperidol, sertraline, paroxetine, and thioridazine are among the common drugs metabolized by CYP2D6.
How do I know if I am a poor metabolizer?
Poor Metabolizer: Medication is broken down very slowly. May experience side effects at standard doses. Intermediate Metabolizer: Slow rate of metabolism. May have too much medication at standard doses, potentially causing side effects.
How do you know if you have a poor metabolizer?
What is a normal metabolizer?
Normal Metabolizer (NM) – This means there are two copies of a normal activity CYP2C19 gene. This results in normal CYP2C19 activity. About 4 out of 10 people have this gene status.
Why do I metabolize drugs so slowly?
Because of their genetic makeup, some people process (metabolize) drugs slowly. As a result, a drug may accumulate in the body, causing toxicity. Other people metabolize drugs so quickly that after they take a usual dose, drug levels in the blood never become high enough for the drug to be effective.
How many drugs are metabolized by CYP2D6?
CYP2D6 metabolizes around 25% of currently prescribed drugs, including various antidepressants, neuroleptics, beta-blockers, opioids, antiemetics, and antiarrhythmics.
What opioids are metabolized by CYP2D6?
Oral opiates (e.g. codeine, oxycodone, and hydrocodone) are metabolized by cytochrome CYP2D6 to metabolites of increased activity (e.g. morphine, oxymorphone and hydromorphone).
What are the activity scores of CYP2D6 metabolizers?
The CYP2D6 phenotype is defined by the sum of the 2 activity scores, which is usually in the range of 0 to 3.0: (22) An UM has an activity score greater than 2.25 A normal metabolizer phenotype (NM) has an activity score of 1.25–2.25 An intermediate metabolizer (IM) has an activity score of >0–<1.25
Which is the best description of the CYP2D6 function?
The CYP2D6 function in any particular subject may be described as one of the following: poor metabolizer – little or no CYP2D6 function intermediate metabolizers – metabolize drugs at a rate somewhere between the poor and extensive metabolizers extensive metabolizer – normal CYP2D6 function
Which is CYP2D6 allele lacks metabolic activity?
Most CYP2D6 polymorphisms result in an allele that lacks metabolic activity. However, the prevalence of poor metabolizer phenotypes varies by racial/ethnic group: Asians (∼1%), Caucasians (5–10%), and Africans (0–19%) [58].
Is the CYP2D6 enzyme an autosomal recessive trait?
A deficiency of the CYP2D6 enzyme is inherited as an autosomal recessive trait; these subjects (7% of Caucasians, about 1% of Orientals) are classified as poor metabolizers. Among the rest (extensive metabolizers), enzyme activity is highly variable, from extremely high in ultrarapid metabolizers, to markedly reduced in intermediate metabolizers.