pharm exam 3: antibiotics & antibiotic resistance

what is protein synthesis

the process bacteria use to make proteins needed to survive and grow

what was the first anitbiotic

penicillin!! #1

what does bactericidal mean

substances that kill bacteria directly but need a growing microbe to do so

what does bacteriostatic mean

only suppresses the growth of microorganisms; halts the bacteria cell activity & growth w/out triggering cell death

what does selective toxicity mean

A property of a drug that allows it to target and kill microbial cells without harming the host's own cells.

what are bad things about antimicrobial therapy

lots of adverse effects; toxicity in people with kidney/liver disease, and unpredictable reactions

what are narrow spectrum antibiotics

these are the best choice and are only active against select microbes. they are best to prevent emergence of resistance

what are broad spectrum antibiotics

they are active against a wide variety of microbes, however are more prone to resistance and superinfections. they disrupt normal flora causing c.diff, thrush, vaginal canidiasis

what are suprainfections

secondary infections that occur during or after the treatment of an initial infection, often due to the disruption of normal flora and overgrowth of resistant organisms.

why is antibiotic resistance bad

makes antibitoics less reliable, $$, threaten ability to provide adequate care

what is resistome

the collection of all antibiotic resistance genes in a given environment or organism.

what is acquired resistance

microbe is resistant to an antibitoic due to the presence of a resistance gene that is not innately present in related bacteria

innate resistance

resistance due to a trait common to all related bacteria

environmental resistance

resistance in non-pathogenic strain of bacteria

what is clinical resistance

resistance noted in pathogenic strain of bacteria

what are the drivers of antimicrobial resistance

DNA mutation, horizontal gene transfer, selected pressure, lack of new antibiotics, biofilm formation and overuse/misuse

how does bactiera still survive antibiotics

the antibiotic will kill sensitive organisms & favor survival of resistant organisms allowing them to survive and multiply with more access to nutrients

what are some things we use in everyday life participating in antibiotic resistance

antibacterial soap over use, food production, environment, and over use/over prescribed

resistance control in clinical

do not discontinue prematueraly, don’t prescribe for viral infections, use narrow spectrum antibitoics first, use first gen drugs and use antimicrobials wisely

what does potency mean

means how much is needed to work

• high = small amount of medication needed

• low = larger amount of drug needed for same effect

what does synergim mean

meaning that drugs work better together and boost each others effects

what does antagonism mean

drugs that work against eachother and interfere with effectiveness

how does antibiotic selection work

before giving antibitoics, identidy which bacteria is casuing the infection so you can choose the antibiotic that works the best; culture, gram stain, PCR for rapid identificaiton

penicillin MOA

works by inhibiting bacterial cell wall synthesis, leading to cell lysis and death. kills gram + and gram - bacteria

inhibits transpeptidoses & activates autolysins

what are transpeptidoses

enzymes that form the cell wall

what are autolysins

enzymes that distruct the cell wall

what is VARIABLE R in penicillin

a side chain that influences acid stability, pharmacokinetic properties, penicillinase resistance and ability to bind specific penicillin-binding proteins - changes the drugs properties

BETA-LACTAM RING with penicllin

this is the part that actually kills the bacteria by inhibiting cell wall synthesis, weakens the cell wall by binding to bacterial penicillin binding proteins

side effects of penicillin

allergic reactions

what do you use to treat penicillin allergic reaction

cephalosproins are used

what are penicillin alternatives

vancomycin, erthromycin, clindamycin

pencillin drug interactions

interact and reduce effectiveness of oral contraceptives

what happens with penicillin overdose

neuromuscular hypersensitivity and consider the counter ion needed (na+ or K+ salt)

what are cephalosporins

A class of β-lactam antibiotics related to penicillin, used to treat a variety of bacterial infections, often effective against Gram-positive and some Gram-negative bacteria.

cephalosporins MOA

disrupt the cell wall synthesis and activate autolysins which distruct the cell wall

resistance of cephalosporins

relates to the production of B-lactamase enzymes called cephalosporinases

cephalosporin elimination

primarily eliminated in kidney, excpet CEFTRIAXONE is eliminated in the liver

adverse effects of cephalosporin

allergic reactions, bleeding, alcohol interactions, precipitates w/ calcium

what are carbapenems

important for pseudomonas aeruginosa and entercoccus but NOT FOR MRSA, mainly for sever infections in hospitals

• merodenum

carbapenems MOA

bind to PBPs (penicllin-binding proteins) and penetrate all tissues in CSF, resistant to most B-lactamases & penetrates Gram - and gram + cell walls

merodenum

a type of carbapenem antibiotic used to treat serious infections, binds to PBPs to stop cell wall synthesis

what is vancomycin

an antibiotic used to treat infections caused by Gram-positive bacteria, including MRSA, staph epidermidis, strep, cdiff, enterococci

vancomycin MOA

it is a powerful antibiotic used to treat serious gram + bacterial infections

vancomycin adverse reactions

hypersensitivity, thrombophlebitis, ototoxicity, nephrotoxicity

c diff infection MOA

G+ spore-forming anaerobic bacillus that infects bowels, spores spread to feces and then remain in the environment for weeks

ALMOST ALWAYS CAUSED BY ANTIBIOTIC USE

symptoms of c diff

abdominal discomfort, nausea, fever, watery dirrhea, toxic megacolin, colitis, colon perforation, sepsis, death

treatment for c diff

stop antibiotic causing CDI and treat with vancomycin or metronidazole

tetracyclines MOA

bacterostatic inhibit bacterial protein synthesis, treats aerobic, anerobic, G-, G+ bacteria

what does tetracycline treat for

rickettsiae (rocky mountain fever), borelia burgdorteri (LYME DISEASE), syphilis, unfortunatly has many resistant bacteria

adverse effects of tetracycline

GI irritation, superinfection, hepatic toxicity, renal toxicity, depression of skeletal growth, dental enamel staining and hypoplasia

macrolides

a class of antibiotics that inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit, effective against various gram-positive and some gram-negative bacteria. MUST TAKE ON EMPTY STOMACH

erythromycin

antibitoic that can be broken down by stomach acid before it ahs the chance to work, to prevent this take by enteric coating, salts, esters, salts of esters

therapeutic uses of erythromycin

BORDETELLA PERTUSSIS (whooping cough), acute diphtheria, chlamydial infections, edocarditis prophylaxis

adverse effects of erthyromycin

QT prolongation and sudden cardaic death

lincosamides

bacteriostatic inhibition of microbial protein synthesis, stops the bacteria from making proteins which prevent them from growing and multiplying, can affect the bacteria for up to 2 weeks after last dose

aminoglycosides MOA

bacterial protein synthesis inhibitor that binds to the 30S ribosomal subunit, resulting in misreading of mRNA and inhibition of translation.

aminoglycosides resistance

has some bacteria that produces enzymes that modify aminoglycosides making the antibiotic ineffective

adverse effects of aminoglycosides

ototoxicity, nephrotoxicity

what does aminoglycosides treat

mycobacterium TB (streptomycin)

sulfonamides

are a group of antibiotics that inhibit bacterial growth by interfering with the synthesis of folic acid

• trimethoprim

trimethoprim MOA

inhibit successive steps in the synthesis of folic acid & this bacterial DNA replication, has an onset lag d/t folic acid stores in RBCs

adverse effects of trimethoprim

crystalluria; need to drink lots of water

fluoroquinolones MOA

inhibit DNA gyrase (enzyme that helps bacteria unwind DNA to be copied)

fluoroquinolones adverse effects

TENDONITIS (achilles rupture)

metronidazole

damages bacterial DNA only active against obligate anaerobic bacteria, for c. diff, trichomiasis, can cause headache, dizziness, vertigo