Phase I detoxification is the first step in the body’s process of metabolizing and eliminating toxins, drugs, and other harmful substances. This phase primarily takes place in the liver and involves a group of enzymes known as the CYP450 (cytochrome P450) family.
The CYP enzymes work to modify the chemical structure of the toxins to make the toxins more polar and reactive, preparing them for Phase II detoxification and elimination. However, in some cases, Phase I reactions can lead to the formation of intermediate metabolites that are more toxic than the original compounds.
CYP enzymes are important in how well medications work for people. For some medications, a slow or fast CYP enzyme can drastically change the effect.
The CYP2B6 enzyme is part of the body’s first line of defense in detoxifying and breaking down certain and important for metabolizing several medications. Genetic variants of this enzyme can either speed up or slow down its function.
Several popular drugs, such as omeprazole, esomeprazole, and clopidogrel are metabolized by the CYP2C19 enzyme. There are important genetic variants in the CYP2C19 gene that changes how fast or slowly these drugs are broken down. Learn how these variants might affect their efficacy.
The CYP2C8 gene is important in the metabolism of several chemotherapy drugs as well as playing a role in the metabolism of NSAIDs. Genetic variants that alter how this enzyme works can impact your reaction to a medication.
The CYP1A2 gene breaks down caffeine, several major prescription drugs, and interacts with smoking. Learn how your genes influence caffeine metabolism and more.
The CYP2D6 enzyme is responsible for metabolizing about 25% of commonly used medications. There are several fairly common genetic variants in CYP2D6 that affect how quickly you will break down a drug.
The CYP2E1 enzyme is part of the phase I detoxification system. Discover how variants might affect your alcohol metabolism and more.
The CYP3A family of genes is involved in metabolizing about half of the drugs on the market today. Check your genes to see if you carry variants that impact the speed at which you metabolize medications.
Have you ever wondered why certain medications don’t work well for you? Genetic variants can change how fast or how slow the medication is broken down in your body. Learn how the CYP2C9 variants impact quite a few prescription medications.
How many cigarettes a day a person smokes – and how hard it is for them to quit – is at least partly dependent on the CYP2A6 gene. This enzyme also metabolizes several important cancer drugs.
This phase I detoxification gene is important in the breakdown of the hydrocarbons produced in smoke and air pollution. It also affects the metabolism of estrogen.