Factors Affecting Metabolism of Anthelmintics

Nowadays, anthelmintic therapy is the main method in the fight with parasitic worms. Anthelmintics, as well as other xenobiotics, undergo structural changes by effect of biotransformation enzymes, when lipophilic substances are transformed to polar substances more easily eliminable from the organism. Generally, biological effects of metabolites and parent compound are different. Activity of biotransformation enzymes is thus the fundamental factor influencing velocity of detoxification and elimination of the compound from the body and duration of drug effect as well. Modulation of biotransformation enzymes' activities can lead to changes in pharmacokinetic parameters of drug itself as well as other xenobiotics and thus to the risk of decrease in desired effect and/or increase in adverse effects with corresponding impact on the quality of drug therapy. In addition, possible risk of drug residues' presence in animal products has to be considered in farm animals. Biotransformation of xenobiotics is affected by many physiological as well as pathological factors. These factors can be divided into inter-individual (species, gender, genetic polymorphism) and intra-individual (age, diet, medication, disease, etc.). All these factors cause wide variability in occurrence and activity of biotransformation..