Drug Excretion

Question 1

_____ is the major and most important organ of excretion

Answer 1

Kidney

Question 2

Drug excretion is the _____ elimination of ________ or ______ from the body via various organs of excretion

Answer 2

Irreversible
Unchanged Parent Drugs/ their metabolites

Question 3

Drugs excreted by large intestine/rectum(biliary and faecal) excretion are:

Answer 3

Vancomycin-antibiotic
Vincristine-anti-cancer drug

Question 4

In the excretion of drugs via tongue(saliva), ___ drugs are excreted in saliva of PH ___ — ___ as a result of ____ diffusion across cells of the _____ and _____. Examples:

Answer 4

Basic
5.8-8.4
Passive
salivary glands and oral epithelium
Phenytoin, diazepam, theophylline, caffeine & lithium

Question 5

Drugs excreted via tears?
Mechanism: occurs by ____ diffusion of ____, _____, ______ molecules from plasma across eccrine and ____ glands.

Answer 5

Cytarabine

Passive
unionized , lipophilic, non-protein bound
Lacrimal

Question 6

Drugs excreted via skin(sweat):

Answer 6

Alcohol, antipyrine, benzoic acid, cocaine, salicylic acid, lead and mercury.

Question 7

____ is excreted by lungs

Answer 7

ANAESTHETICS

Question 8

Example of drug excreted by breast(breast milk):

Answer 8

Aspirin

Question 9

Drugs excreted via Hair:

Answer 9

Methamphetamine
Methoxyphetamine
Phenobarbital

Question 10

Glomerular filtration filters small molecules of size _____ such as ___, ___, _____ and ______ via pores at the base of glomerulus.

Answer 10

< 20000
Salt
Water
Sugar
Unbound drugs

Question 11

Tubular reabsorption occurs by ____ while tubular secretion occurs via ______

Answer 11

Passive diffusion
Carrier -mediated

Question 12

Two types of half life namely:

Answer 12

Biological
Plasma

Question 13

Define biological half life:

Answer 13

Biological half life is the time taken for substance to lose half of its physiological, pharmacological or radioactive activity

Question 14

Definition of Plasma half life:

Answer 14

Plasma t1⁄2 is the time required for the plasma
concentration of a drug to be reduced to half.

Question 15

Plasma half life depends on

Answer 15

Rate of excretion
Metabolism of the drug

Question 16

Factors affecting drug excretion:
(6 factors)

Answer 16

Lipid solubility
PH
Enterohepatic cycling
Particle size
Protein binding
Renal disease

Question 17

Lipid solubility decreases excretion except for drugs excreted via the ____

Answer 17

Lungs

Question 18

Enterohepatic cycling ____ drug excretion and ___ half life
Examples of drugs seen here are:

Answer 18

Reduce
Increase
Tetracycline, chloramphenicol, digitoxin, phenytoin, oestradiol, colchicine, flurbiprofen, leflunomide

Question 19

What drug inhibits excretion of penicillin by competing with it for tubular secretion at PCT thereby prolonging it’s action?

Answer 19

PROBENECID

Question 20

Normal kidney function:

Answer 20

100-130ml/min/1.73m2

Question 21

Kidney function in kidney disease:

Answer 21

<60 ml/min/1.73m2

Question 22

Kidney function in kidney failure:

Answer 22

<15 ml/min/1.73m2

Question 23

Drugs

Answer 23

Tetracycline, chloramphenicol, digitoxin, phenytoin, oestradiol, colchicine, flurbiprofen, leflunomide