ADME Flashcards
What is absorption?
movement of the drug from the site of administration into the blood
What is the rate limiting step of absorption?
dissolution
What is Bioavailability?
- the fraction of a given dose that ends up in systemic circulation
- IV administration considered to be 100%
In what part of the body does most absorption take place?
The least?
- most in the small intestine
- least in the esophagus and aglandular stomach
What is enterohepatic recycling?
a drug is absorbed into portal circulation, metabolized and excreted in bile, then reabsorbed from the small intestine again
What is First-Pass Metabolism?
an oral drug is absorbed into portal circulation, and a portion of that drug is metabolized by the liver before it reaches systemic circulation
What is distribution?
the transfer of drugs from the bloodstream to tissues around the body
What is metabolism?
the chemical alteration of the drug by different body tissues
What is bioinactivation?
the process of making a drug inactive and easier to excrete
What is bioactivation?
when an inactive substance is converted to an active metabolite
What are some enzyme inducers?
- Phenobarbital
- Kale
- Rifampin
What are some enzyme inhibitors?
- Chloramphenicol
- Cimetidine
- Ketoconazole
- Grapefruit juice
What reactions are involved in Phase 1 liver metabolism?
- Oxidation
- Reduction
- Hydrolysis
What happens to a drug that undergoes phase 1 reactions?
- It may be inactivated
- It may be converted to an active metabolite
- It may be converted to a toxic metabolite
- It may produce a product that undergoes a phase 2 reaction
What happens in Phase 2 liver metabolism?
combination of a molecule with a reactive group capable of attaching a substituent group
