drug distribution

True or False: Drugs will differ in their apparent volume of distribution

True or False:
A Vd of only a few litres suggests that the drug stays mainly in the vasculature system

What are two main factors that influence the RATE of drug distribution in the body?

What factors will affect membrane permeability?

True or False:
permeability of drugs is increased in renal capillaries by pores in membrane of the endothelial cells while pores do not exist in the blood brain barrier, making passage of many drugs difficult

Which of the following tissues is/are highly perfused?
heart, lungs, kidney, fat, bone

What factors will affect the EXTENT of distribution of drug in body?

What are some proteins in blood that drugs may bind to?

Acidic drugs usually bind to:
a. albumin
b. AAG

Basic drugs usually bind mainly to:
a. albumin
b. AAG

True or False:
It is only the unbound or free drug that can exert effect at receptor/site of action

What doe we mean by total drug concentration in blood?

If it is unbound or free drug which exerts effect, why can we often measure the total concentration and use this to relate to effect?

Explain what can happen to phenytoin binding in the presence of renal or hepatic disease and why

Why might a free (or unbound) drug concentration be requested for phenytoin in presence of liver disease or renal disease?

Explain why some drugs may concentrate in breast milk

True or False:
With an obese patient, for a drug that distributes into body fat, we would tend to use total body weight if calculating Vd expressed in L/kg while if drug does not distribute well into adipose tissue, we would tend to use IBW

Using physiology model:
Vd=Vp + (fu/fut)Vt
what would happen to Vd of a drug if another drug was co-administered and the fu was increased?
(assume Vp, Vt and fut do not change)

After dosing a patient with digoxin, when should we take a blood sample for drug level monitoring? 3h after dose or wait at least 6h