ADME Metabolism Flashcards
Metabolism means…
the chemical alteration of the drug by different body tissues, also called biotransformation
most drugs are changed in order so they can be eliminated by the kidney by..
made more water soluble, more polar, and more ionized, thus will not cross membranes and be reabsorbed easily.
bio-inactivation means
the process of making a drug inactive and easier to excrete
bio-activation means…
when an inactive substance “Prodrug” is convereted to an active metabolite (in the liver)
lethal synthesis is when
a nontoxic substance is converted to a toxic metabolite (organophosphates)
most drug metabolism occurs in the
live although some occurs at extrahepatic sites such as in the plasma, lungs, kidneys, skin and GI tract.
the liver is the??
main organ for drug biotransfermation differences in drug metabolic rate account for variation in drug activity and toxicity across species
phase 1 reactions includes
oxidative (most common) and reductive (rare) and hydrolytic reactions.
most phase 1 reactions take places in
the hapatocytes and are catalyzed by enzymes attached to the smooth endoplasmic reticulum. most important of these is cytochrome P450
Cytochrome P450 is also called
mixed function oxidase system this is a relatively nonspecific enzyme system
some intermediates of phase 1 reactions may be
more toxic than the parent drug
non-microsomal reactions are reactions not associated with
the smooth ER contribute to some phase 1 RXNs such as alcohol dehydrogenase
Phase 1 RXNs are considered
nonsynthetic
Phase 2 RNXs are considered
Synthetic
What happens in a Phase 2 rxn?
a molecule (endongenous susbance or parent drug or metabolite) with a reactive group conjugates with a substituent group rendering a final metabolite that is typically inactive and water soluble(polar)
