Drug Interactions

Question 1

Therapeutic Index..

Answer 1

is toxic dose (cause toxic effects in half the pop) over the effective dose (cause positive effects in half the pop)

Question 2

We want our therapeutic index to be..

Answer 2

a very large number

Question 3

biologic or clinical response to a drug is reduced by administration of a second drug..

Answer 3

antagonism

Question 4

example of antagonism: penicillin doesn’t work with tetracyclin, because..

Answer 4

penicillin inhibits NEW wall synthesis and tetracycline stops protein synthesis from occuring

Question 5

example of antagonism: tetracyclin doesn’t work with antacid, because..

Answer 5

tetracyclin chelates divalent metal ions, which interferes with absorption and antimicrobial activity (antacid diminishes tetra effects)

Question 6

a second drug with a different activity enhances the activity of the first drug..

Answer 6

potentiation

Question 7

neostigmine potentiates the activity of ________

Answer 7

succinylcholine

neostigmine inhibits psudocholinesterase, and thereby inhibits hydrolization of succinylcholine

Question 8

Example of unexpected drug interaction: __________ inhibits aldehyde dehydrogenase, leading to undesirable effects when taken with alcohol

Answer 8

disulfiram

Question 9

_______ is now used to treat alcoholism

Answer 9

disulfiram

Question 10

the combined activity of 2 drugs acting at the same or similar sites

Answer 10

Summation

Ex. additive, infra-additive, supra-additive (i.e., synergistic)

Question 11

Summation at same site: Opioid morphine and ________

Answer 11

merperidine

Question 12

Summation at different site: midazolam and _________ act together as general anesthetics

Answer 12

sevoflurane

Question 13

The combined activity of 2 drugs produce an effect greater than the maximal effect produced by either drug alone

Answer 13

synergism

Question 14

Carbon tetrachloride is hepato-toxic, and its toxicity is enhanced by ______

Answer 14

ethyl alcohol

Question 15

Example of synergism..

Answer 15

HAART (AIDS therapy)

Question 16

Example of Pharmaceutical interactions..

Answer 16

drugs given parenterally for intravenous sedation; drugs should not be mixed within the same syringe

Question 17

Drugs that affect ____ _____ _____ may also affect metabolism of other drugs.

Answer 17

hepatic blood flow

Question 18

_______ reduces cardiac output, which reduces blood flow to liver, which inhibits clearance of lidocaine

Answer 18

propranolol (Beta adrenergic receptor)

Question 19

Weak acids more rapidly excreted in ______ urine

Answer 19

alkaline

Question 20

Aspirin clearance is increased by administration of..

Answer 20

sodium bicarbonate

Question 21

weak bases more rapidly excreted in ______ urine

Answer 21

basic

Question 22

Amphetamine clearance is increased by administration of..

Answer 22

NH4+Cl-

Question 23

Probenacid competes with _________ for renal tubule transport, thereby increasing its duration in the body

Answer 23

penicillin