Drug metabolism

Question 1

what does metabolism do

Answer 1

makes lipid soluble and non polar compounds water soluble so that they can be excreted. also activates some drugs eg codeine

Question 2

what happens to non water soluble substances

Answer 2

passively reabsorbed from renal or extra renal excretory sites back into the blood

Question 3

important sites of metabolism

Answer 3

liver, lining of gut, kidneys, lungs

Question 4

effects of metabolism

Answer 4

loss of pharmacological activity, decrease in activity, increase in activity, production of toxic metabolites

Question 5

2 phases of metabolism

Answer 5

Oxidation, reduction and hydrolysis to activate/inactivate and then glucoronidation to cause conjugation products

Question 6

what enzymes are majorly involved in drug metabolism

Answer 6

cytochrome P-450

Question 7

cytochrome P450 consists of

Answer 7

number of isozymes with differing substrate specificity and regulatory mechanisms

Question 8

what other factors are important in drug metabolism and toxicity

Answer 8

sulphating, acetylation, glutathione conjugation

Question 9

what can affect inhibition and induction of drug metabolising enzymes

Answer 9

age, sex, nutrition, drug ingestion, disease, smoking (phase1), ethnicity, genetic polymorphisms.

Question 10

what is pharmacogenetics

Answer 10

wide range of response to drugs between individuals due to variation in enzyme efficacy due to allelic variants