Adverse Drug Reactions

Question 1

What is a type A drug reaction?

Answer 1

Type A = Augmented response

an exaggerated, pharmacological effect, generally a predicted response, in relation to the size of the dose

Question 2

What is a type B drug reaction?

Answer 2

Type B = Bizarre

more immune based. small exposure can lead to an immune response. unpredictable. often much more severe.

Question 3

How does c.diff cause clinical disease?

Answer 3

produces entertoxin and cytotoxin

Question 4

How does the skin react in penicillin allergy?

Answer 4

Urticaria = hives

Erythematous eruptions = reddening, macropapular

Question 5

How do you treat anaphylaxis?

Answer 5

adrenaline, steroid, anti-histamine

Question 6

Steven-johnson syndrome is particularly associated with which antibiotic?

Answer 6

vancomycin

Question 7

Name two mechanisms of drug interactions?

Answer 7

Inhibition - inhibit the elimination of other drugs, rise to toxic levels
Induction - induce the metabolism of other drugs, drop to sub-therapeutic levels

Question 8

Give an example of a drug interaction involving induction?

Answer 8

Rifampicin is an incredibly powerful inducer of drug metabolism - accelerates the metabolism of the oral contraceptive pill, drops to sub-therapeutic levels

Question 9

Give an example of a drug interaction involving inhibition?

Answer 9

Macrolides - inhibit metabolism.
use of macrolides at same time as simvastatin, will inhibit the metabolism of the statin, plasma concentration will rise to dangerous levels, could cause muscle damage

Question 10

Give an example of an antibiotic with a wide therapeutic range and a narrow range?

Answer 10

wide: penicillin
narrow: gentamicin

Question 11

How do you dose Gentamicin?

Answer 11

High risk patients: multiple daily dosing.
lower risk: OD
need to measure low trough effect - to avoid toxicity - id ok due to post-anti biotic effect?

Question 12

What method is used to inform how frequently Gentamicin should be dosed?

Answer 12

Hartford Nomogram
in the non-vulnerable patient.
- give a test dose, measure the plasma conc and check which section of the graph it is in within 10 hrs (safe to give 24hr, 36 hr dosing etc)

Question 13

Give an example of a glycopeptide? What are some of the advantages?

Answer 13

Glycopeptide: Vancomycin

pros: excellent activity for MRSA
cons: cannot be IV