F/CL - 6 Flashcards
absolute vs relative bioavailability
absolute is when we are comparing to IV. Relative is when we are comparing to another doage form
example: if the absolute bioavailability is 0.59, that means that 41% of the dose is…
lost before the dose reaches systemic circulation
ORAL BIOAVAILABILITY (F) – AUC
Larger ___ means that the body is exposed to a larger amount of drug.
AUC
Thus, low bioavailability is usually due to poor intestinal ___ and/or high hepatic ___
absorption
metabolism
T or F: Drugs that are poorly absorbed from the intestine are expected to show low F values.
True
T or F: Drugs that experience significant first pass effect are expected to have low F values.
True
Assuming hepatic metabolism and renal excretion are major elimination pathways, urinary excretion accounts for ___ % of total drug elimination.
20%
what is fe
fraction excreted unchanged into the
urine
fe is equal to
CLrenal/CL
___ and ___ bind to RBC significantly. For these drugs, concentrations are typically measured using blood (not plasma) samples.
tacrolimus and cyclosporine
T or F: When a drug is distributed mainly in the plasma, Vd estimated from blood concentration is larger than that from plasma concentration
true
For most drugs that distribute in plasma
CLb ___ CL
CLb > CL
For drugs mainly distributed into plasma, Cb/Cp=0.5, then CLb is equal to
2CL
If a drug is mainly distributed in plasma, AUC blood = ___ of AUC plasma
1/2
T or F: After oral administration of 1 g drug, you obtain plasma drug concentration vs. time. You can estimate AUC from the curve. Using the data, you can calculate CL.
False; cannot do if it is oral, only iv
