Phase I biotransformation reactions are integral to drug metabolism, predominantly involving oxidative, reductive, and hydrolytic transformations. Chief among these are oxidative reactions, which enhance the hydrophilicity of xenobiotics and introduce polar functional groups to facilitate their elimination from the body.

Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into hydroxyphenobarbital. This reaction exemplifies how aromatic carbon atoms undergo oxidation, and other drugs like phenytoin undergo similar processes.

Aliphatic carbon-containing systems also undergo oxidation reactions; p-hydroxy phenytoin is a product of the hydroxylation of phenytoin. This exemplifies the oxidation of aliphatic carbon atoms, a process also witnessed in drugs such as hexobarbital.

Oxidation reactions also occur in benzylic and allylic carbon atoms and carbon atoms alpha to carbonyl and imines. An illustration of this is the conversion of codeine to morphine, which involves oxidation at the benzylic carbon atom. Other drugs, like diazepam, also undergo comparable reactions. However, it's important to underscore that oxidative reactions can sometimes produce reactive metabolites, potentially leading to the toxicological activation of drugs. A classic example is acetaminophen (paracetamol), whose conversion to reactive metabolites can instigate hepatic necrosis.

Oxidative reactions play a pivotal role in phase I metabolism. They act as a detoxifying mechanism, transforming lipophilic drugs into polar metabolites that the body can readily excrete. The complexity of these reactions underscores their importance in drug metabolism, highlighting the need for continued research and understanding in this field.

Z rozdziału 5:

article

Now Playing

5.3 : Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems

Pharmacokinetics: Drug Biotransformation

50 Wyświetleń

article

5.1 : Biotransformacja leków: przegląd

Pharmacokinetics: Drug Biotransformation

33 Wyświetleń

article

5.2 : Faza I Reakcje utleniania: Przegląd

Pharmacokinetics: Drug Biotransformation

148 Wyświetleń

article

5.4 : Faza I reakcji: utlenianie heteroatomów węgla i układów różnych

Pharmacokinetics: Drug Biotransformation

14 Wyświetleń

article

5.5 : Faza I reakcji: reakcje redukcyjne

Pharmacokinetics: Drug Biotransformation

114 Wyświetleń

article

5.6 : Faza I reakcji: Reakcje hydrolityczne

Pharmacokinetics: Drug Biotransformation

8 Wyświetleń

article

5.7 : Faza II reakcji koniugacji: przegląd

Pharmacokinetics: Drug Biotransformation

18 Wyświetleń

article

5.8 : Faza II reakcje: glukuronidacja

Pharmacokinetics: Drug Biotransformation

19 Wyświetleń

article

5.9 : Faza II reakcji: siarczanowanie i koniugacja z α-aminokwasami

Pharmacokinetics: Drug Biotransformation

28 Wyświetleń

article

5.10 : Faza II reakcji: koniugacja glutationu i tworzenie kwasu merkapturowego

Pharmacokinetics: Drug Biotransformation

24 Wyświetleń

article

5.11 : Faza II Reactions: Reakcje acetylacji

Pharmacokinetics: Drug Biotransformation

41 Wyświetleń

article

5.12 : Faza II reakcje: Reakcje metylacji

Pharmacokinetics: Drug Biotransformation

27 Wyświetleń

article

5.13 : Faza II Reactions: Różne reakcje koniugacji

Pharmacokinetics: Drug Biotransformation

7 Wyświetleń

article

5.14 : Czynniki wpływające na biotransformację leków: właściwości fizykochemiczne i chemiczne leków

Pharmacokinetics: Drug Biotransformation

11 Wyświetleń

article

5.15 : Czynniki wpływające na biotransformację leków: biologiczne

Pharmacokinetics: Drug Biotransformation

17 Wyświetleń

JoVE Logo

Prywatność

Warunki Korzystania

Zasady

Badania

Edukacja

O JoVE

Copyright © 2025 MyJoVE Corporation. Wszelkie prawa zastrzeżone