GBP9

Question 1

Name five routes of drug excretion

Answer 1

Expired air, urine, bile, sevum/sweat, breast milk

Question 2

What drugs are excreted in bile

Answer 2

water soluble drugs/highly polar drugs with a mw>350

Question 3

What drug is excreted in sebum/sweat

Answer 3

Tetracycline

Question 4

What drugs cause a problem when excreted via breast milk (4)

Answer 4

Antithyroid drugs, sulphonamides, anticoagulants, ACEinhibitors

Question 5

What are the possible consequences of enterohepatic cycling

Answer 5

Prolongation of drug action

localisation of drug action, prevents systemic side effects (loperamide= immodium)

Question 6

Name four drugs that are renally excreted

Answer 6

• aminoglycosides
• some cephalosporins
• some penicillins
• methothrexate
• digoxin
• lithium

Question 7

What happens to protein bound drugs in the kidney

Answer 7

minimal filtration when bound but binding is weak and readily reversible

Question 8

Other than glomerular filtration what ways can drugs be moved in and out of the kidney

Answer 8

Active secretion of acids and bases

Passive re-absorption dependant on pka ph and lipid solubility

Question 9

What effect does urine flow rate have on reabsorption

Answer 9

Increased urine flow rate decreases reabsorption

Question 10

How can urine flow rate be taken advantage of in overdose

Answer 10

With an overdose of an acidic drug can use an alkali diuretic (ionised)
and an acidic diuretic with alkali drug

Question 11

Why is renal impairment a consideration when choosing dosage

Answer 11

Renal impairment might reduce excretion and elimination of a drug leading to toxic build up in plasma concentration.

Question 12

How might renal function be assessed

Answer 12

Creatanine clearance (eGFR>90=normal)