Exam 2 Flashcards
What is the definition of drug-drug interactions?
the administration of drugs concurrently or sequentially
What two therapies are examples of beneficial drug interactions?
combined antihypertensice therapy and combined antimicrobial therapy
What are four examples of beneficial drug interactions
clavamax, anesthesia, anti-cancerous drugs, anti-hypertensive
What are some examples of undesirable drug interactions?
amionglycoside antbiotic-aminoglycoside antibiotic
aminoglycoside antibiotic-muscle relaxant
chloroaphenicol-phenobarbital
undesirable drug interactions are especially important using drugs that have ______
a narrow safety margin
ex: oral anticoagulants, antiarrythmics, cardiac glycosides, anti-cancer drugs)
what are the types of drug-drug interactions?
summation
potentiation
synergism
antagonism
what is summation?
sum of the effects of the drugs, each retains its own effect
ex: two anticoagulants
what is potentiation?
intensification/enhancement of response
the combined effect is greater than the sum of the two drugs acting independently
two drugs have different actions
ex: probenicid-penicillin G, epinephrine-procaine
what is synergism?
the exaggeration of the effect of a drug by giving another drug that has the same action
ex: neuroleptic-inhalation anesthetic, trimethoprim-sulfonamide
what is antagonism?
administration of a drug results in decrease in the pharmacological response of another drug
what are the four types of antagonisms?
physical
chemical
physiological
pharmacological
What is an example of physical antagonism and what kind of molecules is it for?
activated charcoal
large molecules
what is a chemical antagonism?
EDTA and lead, heparine and protamine
has chemical bond
what is the difference between physiological and pharmacological antagonism? give examples for each
physiological: reverse effect, different receptors
ex: epinephrine and histamine (local effect to prevent systemic)
pharmacological: same receptors, reverse mechanism
competitive is reversible. ex: atropine and acetylcholine
noncompetitive is non-reversible. ex: phenoxybenzamine and epinpehrine
