How Do Drugs Work? (pharmacodynamics)

Question 1

What factor affect drug distribution?

Answer 1

▪️lipid solubility
▪️how much of the drug is bound/ free in the blood
▪️blood flow in the area of the drug- tissue penetrance
▪️how permeable are he capillaries (BBB)

Question 2

Drug bound to proteins

Answer 2

▪️albumin
▪️glycoproteins
▪️lipoproteins

Question 3

What are drug targets?

Answer 3

▪️cellular receptors 
▪️enzymes 
▪️transport proteins
▪️structural proteins 
▪️nuclei acids

Question 4

Efficacy and EC50 and IC50

Answer 4

▪️the ability to produce a desired result
-effective ness
▪️EC50-concentration of the drug that gives 50% of the maximum effect
▪️IC50- how much of a particular drug or other substance is needed to inhibit a given biological process by half

Question 5

Therapeutic index

Answer 5

▪️the range of the bad effect : good effect of the drug
-toxic dose: therapeutic dose
▪️better and safer to have a larger therapeutic index than a smaller one as there is a larger number of dosages to pick from that are in the therapeutic range before you get to the toxic range.

Question 6

How to work out therapeutic index?

Answer 6

▪️TD50/ ED50 (Toxic and effective doses in 50% of the population)
▪️the therapeutic index has many limitations, notably the fact that LD50 cannot be measured in humans and, when measured in animals, is a poor guide to the likelihood of unwanted effects in humans.

Question 7

Variability in people?

Answer 7

▪️weight/height 
▪️age/sex
▪️genetics
▪️health 
▪️placebo effect

Question 8

Variability of a drug?

Answer 8

▪️dose
▪️formulation 
▪️route of administration 
▪️resistance/ tolerance 
▪️interactions