ADME Flashcards
What kinds of drugs can pass through the cell membrane readily?
Non-ionized, they are lipid soluble
Where do weak acids get readily absorbed?
Stomach
Where do weak bases get readily absorbed?
Small intestines
What are the two kinds of transport proteins that influence absorption of drugs?
- Uptake
2. Efflux
What is the main difference between the two kinds of proteins that influence absorption of drugs?
Uptake - promotes absorption
Efflux - limits absorption
What is the CYP enzyme that is relevant in the GI tract?
CYP3A4/5
How does the CYP enzyme affect absorption?
Can limit absorption of certain CYP3A4 substrate medications, like simvastatin
How do you calculate Systemic drug exposure?
AUC = ng*hr/mL
How do you calculate bioavailability?
AUC (po) x Dose (iv) / ( AUC (iv) x Dose (po) )
What affects drug distribution?
- Lipid solubility
- Uptake / Efflux proteins
- Plasma protein binding
- Molecular size
- Organ blood flow
(T / F) Half of the drugs are usually protein bound
False, 10-99% are protein bound
What kind of plasma protein binding drugs can enter cell membranes easily?
Free unbound ones
What kind of plasma protein binding drugs CANT enter cell membranes easily?
Highly protein bound
What are the reactions involved in phase I metabolism?
Oxidation, hydrolysis, reduction
What is the main purpose of metabolism?
To make drugs more water soluble and thus more easily renally excreted
