Rapid or Ultrarapid Metabolizers. These enzymes are very active, often breaking down drugs before they can have any effect. If you metabolize a drug in this way, you may require a higher dose in order for the drug to work properly.
Why do I metabolize medication so FAst?
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.
What does it mean to be a CYP2C19 rapid metabolizer?
Ultrarapid Metabolizer (UM) – This means there are two copies of a CYP2C19 gene with increased activity. This results in very high CYP2C19 activity. About 5 out of 100 people have this gene status. Certain drugs should be used with caution and patients may need to have their doses of some medications adjusted.
What is an extensive metabolizer?
Extensive metabolizer: Considered a “normal” rate of metabolism. Patients are likely to metabolize medication normally and medication is likely to work as intended. Ultrarapid metabolizer: Patients in this group metabolize medications too quickly to experience relief from symptoms of depression or other disorders.
What is a poor metabolizer mean?
Poor Metabolizer (PM) – This means there are two copies of low or no activity genes. This results in very little to no CYP2C19 activity. About 2 out of 100 people have this gene status. Certain drugs should be avoided and patients may need to have their doses of some medications adjusted.
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.
What happens if you inhibit cytochrome P450?
Cytochrome P450 enzymes can be inhibited or induced by drugs, resulting in clinically significant drug-drug interactions that can cause unanticipated adverse reactions or therapeutic failures. Interactions with warfarin, antidepressants, antiepileptic drugs, and statins often involve the cytochrome P450 enzymes.
What drugs are affected by CYP2C19?
Other drugs that are affected by CYP2C19 gene polymorphisms include proton pump inhibitors, used to treat stomach ulcers and other conditions; antidepressants, used to treat psychiatric disorders; anticonvulsants, used to treat seizure disorders; hypnotics and sedatives, used as sleep aids; antimalarial drugs, used to …
How common is CYP2C19?
The CYP2C19*2 allele frequencies are ~15% in Caucasians and Africans, and ~29–35% in Asians (2). Approximately 6–12% of the observed variability in antiplatelet effect of clopidogrel is thought to be attributed to CYP2C19*2 allele(s) (58).
What medications are metabolized by CYP2C19?
CYP2C19 catalyzes the metabolism of several drugs, including proton pump inhibitors (PPIs) (e.g., omeprazole, lansoprazole, pantoprazole), antidepressants (e.g., citalopram and amitriptyline), antiplatelet drugs (e.g., clopidogrel), antifungals (e.g., voriconazole), and anticancer compounds (e.g., cyclophosphamide).
Do poor metabolizers need higher doses?
Up to 7% of Caucasians are poor metabolizers of drugs metabolized by the CYP2D6 enzyme. People who cannot metabolize a drug will require a much lower dose than is recommended by the manufacturer, and those who metabolize it quickly may require a higher dose.
Is poor metabolizer a phenotype?
The poor metabolizer (PM) phenotype occurs when both alleles of either CYP2D6 or CYP2C19 carry inactivating mutations and give rise to synthesis of enzyme with impaired activity or no synthesis of enzyme at all.
How are drugs metabolised in the body?
Drugs can be metabolized by oxidation, reduction, hydrolysis, hydration, conjugation, condensation, or isomerization; whatever the process, the goal is to make the drug easier to excrete. The enzymes involved in metabolism are present in many tissues but generally are more concentrated in the liver.