Lecture 8- drug interactions

Question 1

why do you get less antimicrobial activity when you use PCN and tetracycline together rather than either alone?

Answer 1

PCN inhibits bacterial wall syn.
Tetra inhibits bacterial protein syn.

PCN inhibits new cell wall syn. BUT bacteria must be actively divinding (syn. protein) for this to happen

Question 2

taking antacid (Ca(CO3)) will diminish the effectiveness of …

Answer 2

tetracycline

Question 3

tetracycline …. divalent metal ions. … interferes with absorption and antimicrobial activity

Answer 3

chelates

chelation

Question 4

… is when a 2nd drug with a different activity enhances the activity of the first drug

Answer 4

potentiation

Question 5

what are 3 ways that potentiation can happen

Answer 5

2nd drug either:

1. enhances absorption of 1st drug
2. alters distribution of 1st drug
3. inhibits elim. of 1st drug

Question 6

… potentiates the activity of succinylchlone

Answer 6

neostigmine

Question 7

how does neostigmine potentiate succinylcholine?

Answer 7

neostigmine inhibits pseudocholinesterase (which hydrolyzes succinylcholine) so this will increase the plasma half like of succinylcholine

Question 8

disulfiram was originally developed to treat parasitic infections but was found to be an inhibitor of …. thus producing undesirable side effects if taken with alcohol due to the accumulation of …

Answer 8

aldehyde dehydrogenase

acetaldehyde

Question 9

disulfiram is now used to treat

Answer 9

alcoholism