Xenobiotics are substances that are taken into the body and are found at higher than normal levels (or found when they should not be found at all).
Dealing with xenobiotics is a part of pharmacokinetics (the elimination; metabolism part) and it is done in two phases:
- Phase 1 reaction involves activation of the drug/metabolite by oxidation, hydration, reduction and hydroxylation. These reactions are carried out by CYP450
- Phase 2 reactions involve conjugation of the molecule to glucoronic acid,