Drug Metabolism Flashcards
____________ is a drug that reduces the intestinal absorbtion of cholesterol.
Ezetimibe
NOTE: It interferes with the sterol transporter system
What is known about elimination, in zero order kinetics, when clearance is constant?
When clearance is constant, the rate of drug elimination is directly proportional to drug concentration
How is creatine clearance calculated?
[(140-age) x (weight in kg)]/ (72 x serum creatinine in mg/dL)
NOTE: For women, the result should be multiplied by 0.85
What are the metabolites of atropine?
Tropic acid and tropine
What are the metabolites of propranolol?
Hydroxypronolol, which is an active metabolite
What are the results of metabolism of acetaminophen by CYP450?
Acetaminophen is converted to the reactive metabolite N-acetylbenzoquinoneimine, which can cause liver necrosis
What are the cellular sites of drug metabolism?
Cytosol
Mitochondria
Lysosomes
SER
What are the genetic variants of CYP2C9? What is the significance of each variation?
CYP2C9*2
- Impaired functional interactions with the flavoprotien
CYP2C9*3
- Decreased metabolic activity for warfarin
What are the common substrates of CYP2D6?
Codein
What are the common substrates of CYP2C9?
Warfarin, phenytoin
What are the common substrates of CYP2C19?
S-mephenytoin
What are the common substrates of CYP1A1?
Polycyclic hydrocarbons
What is the major metabolite of morphine?
morphine 3- glucoronide (inactive)
NOTE: Morphine-6-glucoronide is also a metabolite and is active
What are the major substrates of CYP1A2 enzymes?
Theophylline
Acetaminophen
Glucuronidation is decreased in neonates. What is the clinical significance of this?
Can lead to gray baby syndrome, due to the accumulation of chloramphenicol
