Term
| What is Biotransformation? |
|
Definition
The chemical alteration of a drug eirther
1. Drug - - Inactive metabolite - Morphine
2. Drug - - Active metabolite - imipramine – desipramine (much more active than parent compound)
3. Prodrug - Drug -
Levodopa - dopamine
codeine - morphine
|
|
|
Term
|
Definition
| Reduction, Oxidation or Hydrolysis of the drug in the liver |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
Phase 1 - –Local Ansthetic ..procaine..psudocholinesterase
|
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
Phase II biotransformation
|
|
Definition
Conjugation of a drug or Phase I metabolite which is easily excreted in urine
|
|
|
Term
|
Definition
| Phase II - chloramphenicol |
|
|
Term
|
Definition
| Phas II - Isoniazid, hydrallazine, procainamide |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
Gluathione(GSH) conjugation
|
|
Definition
|
|
Term
Pseudocholineesterase deficiency
1. Defect?
1. Test
2.results in |
|
Definition
1. Cannot metabolise Succinyl CoA
2. Dibucaine number - identifies people with defect
3.Succinyle CoA apnea - Prolonged neuromuscular paralysis
|
|
|
Term
Slow Acelyators
1. Defect
2. Drugs |
|
Definition
1.drug induces SLE (butterfly rash)
2. Isoniazide , procainamide, hydralazine |
|
|
Term
| WHat drugs increase synthesis of CYP450 in liver? |
|
Definition
1. Phenobarbitone
2. carbamezapine
3.phenytoin
4.rifampine
5. aromatic hydrocarbons (smoking) |
|
|
Term
Give an example of a drug that decreases duration and intensity of another drugs action
|
|
Definition
phenytoin with oral contraceptives
failure of contraception
|
|
|
Term
Example of a drug which demonstrates tolerance (the requirement of a higher dose to elicit the given response)
|
|
Definition
|
|
Term
CYP 450 enzyme inhibitors
examples...
|
|
Definition
cimetidine,grapefruit juice, erythromycin, azole antifungals- ketoconazole, HIV protease inhibitors
... leads to less enzyme thus it wont be metabolised and eliminated it accumilates thus more toxicity of drugs
|
|
|
Term
CYP 1A1
1. Drug substrate
2.Inducers
3.Inhibitors |
|
Definition
1. Theophylline & Acetaminophen
2. Smoke (aromatic hydrocarbons)
3. Quinolones & Macrolides
|
|
|
Term
CYP 2C9
1. Drug substrate
2. Inducer
|
|
Definition
1.Phenytoin & Warfarin
2. Phenobarbitone, Phenytoin & Rifampin
|
|
|
Term
CYP 2D6
1.Drug substrates
3. Inhibitors |
|
Definition
1. CVS & CNS drugs
2. Haloperidol & Quinidine |
|
|
Term
CYP 3A4
1. Drug substrates
2. Inducers |
|
Definition
1. 60% of drugs
2. Anticonvulsants & Rifampin
|
|
|
Term
Toxic Metabolism
give an example |
|
Definition
•Some drugs can be converted to its active/toxic forms after metabolism leading to tissue injury
•Eg: acetaminophen is converted to a reactive metabolite N-acetyl-p-benzoquinoneimine which is conjugated with glutathione (GSH)
•In overdoses the glutathione gets depleted, so the reactive metabolite combines with essential hepatic cell proteins- leads to cell death
•Rx: Administration of acetylcycteine which replenishes the glutathione
|
|
|
Term
Acetaminophen OD.. what happens?
how is it treated?
|
|
Definition
Toxic metabolism (hepatotoxicity)
- glutathione stores are depleted which conjugates it
-Administration of acetylcycteine which replenishes the glutathione
|
|
|
