Walters - Antimicrobial Principles Flashcards
T/F bacteristatic antibiotics do not directly kill bacteria, instead they inhibit metabolic pathways thus weakening the organisms and then relying on the patients immune stystem to clear the infection
true; organism functionals normally until it runs out of product;
____antibiotics outright kill bacteria, mostly by causing lysis
Bactericidal;
What are factors to consider when choosing an antibiotic
- Resistance
- Age
- hepatic function
- genetics
- disease state
- pregnancy
- site of infection
- route of administration
bacteriostatic or bactericoidal depend on:
dose and organism being treated
How can resistance occur
- pumping the antibiotic back out of cell before it causes damage
- finding alternate routes to synthesize compound whose usual mode of synthesis is inhibited
- increasing the expression of an enzyme otherwise inhibited by the antibiotic.
Renal function deterioates with age which can cause drug _____ and inc side affects. Penicilin can cause ____ such as seizures and coma. Aminoglycosides increases ____ and ototixicity, especially in pregnant women
accumulation; neurotoxicity; nephrotoxicity
Neonates have low ____. Sulfonamides also prefers to be bound to albumin and bounce bilirubin off which causes it to inc in circulation and brain and cause _____
albumin; kernicterus
____cross the placenta and are excreted in breast milk and deposit in teeth and bone where they discolor teeth and cause slow bone growth
Tetracycline
_____cause cartilage damage and arthropathy, especially in pregnant women or small kids
Fluroquinolones
_____ , a macrolide, gets excreted unchanged in bile.
Azithromycine
____is one route of drug metabolism and is more rapid in Asians. ______ phosphate dehydrogengase is a scavenger enzyme that protects cells from free radicals. A decrease in this causes risk of damage.
Acetylation; glucose 6
increase of _____, nitrofurantoin, and _____ can cause a lot of free radicals if low levels of G6PD
sulfonamides; chloramphenicol
____are structurally similar to oral hypoglycemic drugs used to stimulate insulin release in diabetics. Sulfonylureas, and sulfonamides block the ____channel causing positive charges to accumulate inside the cell which causes Ca++ to release insulin. This is how sulfonamides can potentiate the hypoglycemic effect of oral sulfonylureas.
Sulfonamides; K+
IV antibiotics are often administered in ____. The extra sugar can contribulte to hyperglycemia in diabetics
D5W
In most cases you try to reach the _____ or higher. However, absecess can alter ____ causing changes in drug activity. ____ are inactive due to unfavorable pH, so the site must be drained before giving aminoglycosides.
MIC; pH; Aminoglycosides (treat gram - infections)
____ and ____ must be given parenterally for systemic effects, but they can be given orally for a local action in the gut
Aminoglycoside; vancomycin
_____, cephalosporins, and _____ can give false + test for urine sugar if using a test that measures reducing substances such as _____. You can avoid this by using tests that measure glucose directly such as ____ or labstix
Penicillins; tetracycline; Dextrostix
Why do we use drugs acting by different mechanisms
Organism wont find a way to get around of by both drugs.
what does synergism mean
the two drugs together will produce a greater effect greater than the sum of either drug alone; its more than additive
_____inhibit the very first step in the synthesis of folic acid: _____. Trimethroprim inhibits the synthesis of folic acid in a later step. Together sulfanomides and trimethroprim are synergistic.
Sulfonamide; dihydropteropate synthase
Penicillins enhance the uptake of ______ and streptomycin; a combination useful in treating _____ endocarditis
gentamicin; enterococcal
what are examples of aminoglycosides
gentamicin and streptomycin
What type of antibiotic are sulfonamides
static
what is the mechanism of action of sulfonamides
inhibit dihydropteroate synthase (first step in the synthesis of folic acid)
