Thus, the drug metabolism may be reduced through inhibition by another drug or compound. Version B. Briefly describe the types of reactions involved in Phase I metabolism. These reactions include oxidation, reduction, and hydrolysis. Oxidation is the addition of oxygen or removal of a hydrogen atom. Examples might include formation of alcohols or phenols.
Reduction is the removal of oxygen or addition of hydrogen.
Examples include the reduction of a nitro to amine group. Hydrolysis is the addition of water to a molecule usually resulting in the subsequent breakdown of the molecule. Examples might include the hydrolysis of esters and amides. Version C. Briefly describe enterohepatic recycling. Drugs are extensively excreted into bile may be subject to enterohepatic recycling.