Antibiotics Flashcards
Cephalosporin
Beta Lactation antibiotics that are derived from acrimonious fungus
MOA cephalosporins
Inhibit bacteria wall synthesis
Bactericidal
Are cephalosporin penicillinase resistant
Yup
Not susceptible to penicillinases
Each new generation of cephalosporin has greater gram _ properties
Negative
Side effects cephalosporin
Hypersensitivity reactions vitamin k defiency
Disulfiram like reaction with alcohol
Increased nephrotoxicity of aminoglycosides
Hypersensitivity cephalosporin
Same with penicillin
Careful giving to people with penicillin allergies
Rashes, hives, itchy eyes, swollen tongue
Cephalosporin vitamin k
Cephalosporin activates vitamin k, causing defiency
Alcohol and cephalosporin
Disulfiram like reaction-flushing, fast heartbeat, nausea, thirst, chest pain, vertigo, low bp
Occurs as a result of accumulation of acetaldehyde due to inhibition of acetaldehyde dehydrogenase
Increased nephrotoxicity of aminoglycosides with cephalosporin
Demonstrate synergistic nephrotoxicity interaction when used in combination
1st generation cephalosporin
Beta Lactation antibiotics that are derived from acrimonious fungus. Inhibit bacterial cell walls ynthesis. Not susceptible to peniciliinases.
Not strong gram -
Examples of first generation cephalosporin
Cefazolin and cephalexin
What are 1st gen cephalosporin effective against
Proteus mirabilis, E. coli, klebsiella pneumonia and gram positive cocci
Cefazolin
Intramuscular
Gram + bacterial infections of the skin but more severe infections involving bon,e lungs, GI and urinary tract. Also pre operative prophylaxis
Cephalexin
Orally
Gram positive infections int he middle ear, bone, lungs, and skin. Also endocarditis prophylaxis
Indications for 1st gen cephalosporin
Proteus mirabilis
E. coli
Klebsiella
Gram positive cocci
2nd gen cephalosporin
Cefoxitin, cofactors and cefuroxime
For proteus mirabilis, E. coli, klebsiella, haemophilus influenza, enterobacter, neisseria, serratia marcescens and gram positive cocci
Cefoxitin
Gram negatives, gram positive and even anaerobes.
NOT for active against pseudomonas and enterococci
Cefaclor
For septicemia, pneumonia peritonitis, UTI and biliary tract infections. It is active against both gram positive and gram negative bacteria
Cefuroxime
Unlike other second generations can cross the BBB and is active against haemophilus influenza, neisseria gonorrhea and Lyme disease
Indications for 2nd generation
Proteus mirabilis E. coli Klebsiella Gram positive cocci Haemophilus influenza Enterobacter Neisseria Serratia marcescens
3rd generation cephalosporin
Ceftriaxone, cefotaxime, and ceftazidime
Broad spectrum
Good against gram negative organisms resistant to other beta lactate
Cefotaxime
Respiratory infections, CT, urinary tract, genita tract, meninges, and blood. Can cross the BBB
Most gram negative bacteria (espicially pseudomonas) also gram positive cocci, except enterococcus
Ceftriaxone
Community acquired pneumonia, haemophilus influenza infection, and can be used for bacterial meningitis.
GONORRHEA from dingle muscular injection
Can cross the BBB
Cefdinir
Pneumonia, bronchitis, ear infections, sinusitis, pharyngitis, tonsillitis, skin infections.
Side effects cefdinir
Can bind iron in GI and cause red stool
Diarrhea, vaginal infections, nausea, head ache, abdominal pain
Ceftazimidime
Gram positive and gram negative bacteria. ACTIVE AGAINST PSEUDOMONAS
Whic third generation cephalosporin should i use for pseudomonas
Ceftazidime
Indications for 3rd gen cephalosporin
Serious gram negative infections, which are typically resistant to other beta Lactation antibiotics
4th gen cephalosporins
Cefepime
Broad spectrum of activity and further increased activity against gram negative organisms resistant to other beta lactams
Used for pseudomas a
Cefepime
For moderate-severe hospital acquired infections by multi resistant bacteria such as pseudomonas and can cover resistant strep p as well as enterobacteriaceae
Indications 4th gen cephalosporin
Increased activity against gram positive infections and pseudomas and gram positive infections like staph a…also gram -
5th generation cephalosporin
Broad spectrum
Specifically created for resistant organisms such as MRSA
Indications 5th generation cephalosporin
Resistant bacteria like MRSA
Broad spectrum against gram positive and gram negative
Examples of 5th generation cephalosporin
Ceftobiprole
Ceftaroline
Ceftobiprole
Antipseudomonal (binds strongly to penicillin binding protein 2a)
MRSA, strep p, enterococci, health care associated pneumonia (powerful antipseudomnonal)
MRSA which are less susceptible to daptomycin , vancomycin or linezolid
Ceftaroline
Broad spectrum activity against many gram positive organisms, such as MRSA, MRSE, and VRE.
Not great for gram - bacteria like bacteroides
NO PSEUDOMONAS COVERAGE
Protein synthesis inhibitors
Slows or stops the growth or proliferation of cells by disrupting the generation of new proteins, usually the ribosome level
Protein synthesis inhibitors prok vs euk
Effect only prokaryote 30 50s =70s
Protein synthesis inhibitors of 30s ribosome
Aminoglycosides
Tetracyclines
Protein synthesis inhibitors 50s
Chloramphenicol Clindamycin Erythromycin Linomycin Linezolie
Aminoglycosides
Bactericidal
Inhibit formation of the initiation complex and cause misreading of. MRNA. They require oxygen for uptake and are ineffective against anaerobes and are typically used for severe gram - rod infections
Tetracyclines
Bacteriostatic
Prevent attachment of 30s to aminoacyl-trna
Examples of tetracyclines
Doxyclycline
Demeclocycline
Minocycline
What are tetracyclines used for
Lyme
H pylori
M pneumoniae
Rickettsia and chlamydia
Chloramphenicol
Bacteriostatic inhibits 50s peptidyltransfersase
Why is chloramphenicol rarely used in the US and more in developing countries
Severe toxicities-anemia, plastic anemia and gray baby syndrome
But its cheap
Clindamycin
Bacteriostatic
Blocks peptide bond formation at 50s
What in clindamycin used for
Bacteroides fragility and clostridium perfringens above the diaphragm
Erythromycin
Inhibits protein synthesis by binding to the 23 rRNA and 50s subunit and blocking translocation
What in erythromycin used for
Atypical pneumonia caused by mycoplasma, chlamydia and legionella as well as URI and TDS
Lincomycin
Binds 50s similar structure to macrolides
Why in lincomycin rarely used
Adverse effects and toxicity
Reserved for patients with penicillin allergies and high resistant bacteria
Linezolid
Binds 50s for gram positive infections that are resistant to other antibiotics like strep, vancomycin resistant enterococci, mrsa
Indication for linezolid
Infections of skin, soft tissue and hospital acquired pneumonia
Linezolid (zygote)
Bacteriostatic part of oxazolidinone class inhibit 50s
What is linezolid used for
Gram positive causes of pneumonia and skin infections as well as MRSA and WRE
Why linezolid not commonly used
Expensive, severe adverse effects, hard to obtain
Side effects linezolid
Bone marrow suppression, serotonin syndrome
What is linezolid used for
Drug resistant organisms!
What is the oxaxolidinone family
Heterocyclic, nitrogen containing, organic 5 members ring compound. Approved by FDA in 2008
MOA linezolid
Binds 23 rRNA of 50s to prevent formation of functional 70s
Inhibits protein synthesis
Bacteriostatic
Indication linezolid
Gram positive organisms
(Staph and strep)
MRSA
VRE
Side effects linzidolin
Bone marrow suppression (decreased palatable count)
Peripheral neuropathy
Lactic acidosis
Serotonin syndrome
When on linezolid taken with tyramine containing for
BAD get tyramine excess causing dangerous bp changes and the associated symptoms of chest pain, tachycardia, confusion, headaches, nausea, and vomiting, vision changes epistaxis and anxiety
Aminoglycosides
Irreversibly bind 30S interfere proofreading and can inhibit translocation of peptidyl tRNA and can disrupt bacterial cell membrane
Indication for aminoglycosides
Gram negative aerobes (pseudomonas, enterobacter, mycobacteria)
Serious septicemia, GI infections, UTI and hospital acquired pneumonia
Why do aminoglycosides not work well with anaerobic bacterial infections
Require oxygen uptake by bacteria
Side effects aminoglycosides
Nephrotoxicity and ototoxicity
Why aminoglycosides cause nephrotoxicity
Inhibits protein synthesis in renal cells and can lead to acute tubular necrosis and renal failure…common when given with cephalosporins
Ototoxicity is common when aminoglycosides are given with ___
Loop diuretics
Pregnancy and aminoglycosides
No teratogen
Resistance to eminoglycosides
Yea due to certain transferase enzymes that inactivate the drug. They alter the structure of aminoglycosides through various chemical reactions such as acetylation, adenylation or phosphorylation
Example of aminoglycosides
Gentamicin Neomycin Amikacin Tobramycin Streptomycin
Gentamicin
For gram negative infections such as pseudomonas and proteus, but is not for neisseria of legionella.
Gentamicin side effects
Ototoxicity and nephrotoxicity
Administration gentamicin
Not orally due to lack of SI absorption
Why is gentamicin often used to coat surgical implants and told
Heat stable
Neomycin
For bowel surgery prep
Highly ototoxicity and nephrotoxicity
Not absorbed in intestine
Treats hepatic encephalopathy by eliminating ammonia producing bacteria inthe intestine or to reduce the risk of infection during intestinal surgery by eliminating intestinal bacteria
Amikacin
Pseudomonas, enterobacter, serratia infections,
Nephrotoxicity
Ototoxicity.
Can’t be given orally and dosing should be carefully monitors with renal failure
Tobramycin
Gram negative infections , better than gentamicin with pseudomonas lung infections
Can’t be given orally
In ophthalmic solution (tobrex) for bacterial conjunctivitis.
Ototoxicity and nephrotoxicity
Streptomycin
Mycobacterium tb
Endocarditis, yersinia pestis infestation and tb
Ototoxicity and nephrotoxicity
MOA aminoglycosides
Bactericidalbind 30s and inhibit formation of the initiation complex required to translate abcteria mRNA cause misreading of RNAand premature termination or protein synthesis
-interferes with proofreading
RequiresO2 uptake
Only aerobes
Resistance to amionglycosidases
Transferase enzymes in plastics and transposons
Acetyltransferases, phosphotransferases and adenyltransferases
Indications for aminoglycosides
Gram negative rod infections
Synergistic with b lactma antibiotics-can add espicially for endocarditis
(Ampicillin and gentamicin)
Side effects eminoglycosides
Nephrotoxicity espicially when used with cephalosporin
Ototoxicity with look diuretics (furosemide)
Teratogen-category D
Macrolides
Macrolides lactone ring
Bind 23s rRNA of 50s to block translocation
Bacteriostatic
Examples of macrolides
Erythromycin, azithromycin and clarithromycin
Indication for macrolides
Gram positive cocci, atypical pneumonia’s, chlamydia
Resistance to macrolides
Alteration of 23S RRNA binding side, usually by post transcriptional methylation
Macrolides are potent inhibitors of __, espicially ___
Cytochrome p450
CYP3A4…can elevate other drugs
What combination should be voided with macrolides
Statins—-MTOPATHY
Side effects macrolides (erythromycin and clarithromycin)
QT prolongation ,which can lead to torsades de pointes
Macrolides exhibit enterohepatic recycling. What’s that
Absorbed int he gut and sent to the liver where it is excreted back into the duodenum in bile…can lead to buildup and cause nausea and GI distress (diarrhea)
Macrolides and liver
Hepatotoxicity-direct and immunoallergic effect..
Is immunoallergic will get rash and peripheral eosinophils
MOA macrolides
Bacteriostatic
Erythromycin
GI disturbances be is a motility agonist. Can treat gastroparesis
Prolonged QT
Azithromycin (Zithromax or Zmax)
Derived from erythromycin
Prevents bacterial infections, espicially middle ear infections, strep throat , pneumonia, and sinusitis. Also effective against STD (chlamydia)
Cardiovascular effects-qT prolongation
Clarithromycin
Treat pharyngitis, tonsillitis, maxillary sinusitis, pneumonia and acut bacterial exacerbation of chronic bronchitis.
Why can clarithromycin be taken orally
Acid stable and best bioavailability
Indication for macrolides
Gram positive cocci
Atypical pneumonia
Chlamydia
Resistance to macrolide
Alterations of the 23s rRNA binding site usually by post transcriptional methylation
Macrolides side effects
Diarrhea Prolonged qt interval P450 inhibitors Cholestatic hepatitis Skin rash Eosinophilia
Neomycin sulfate
Aminoglycoside that targets aerobic gram negative bacilli
Not absorbed in GI tract and do not enter CSF
Indication for neomycin sulfate
Topical infection
Prophylaxis for patients scheduled for intestinal surgery
Side effects neomycin sulfate
Ototoxicity, nephrotoxicity, rash, blood dyscrasias
Monitor patients for GI superinfection
MOA neomycin sulfate
Aminoglycoside disrupts protein synthesis and causes rapid bacterial death. Bactericidal
Side effects neomycin sulfate
Ototoxicity, nephrotoxicity, rash, blood dyscrasias
GI superinfection -minotor
Penicillin
From penicillium fungi
Penicillin G, V, benzathine
All are beta lactate antibiotics
Widely used for gram positive organisms and spirochetes
MOA penicillin
Binds to penicillin binding protein which is also known as the enzyme transpeptidase, a critical enzyme involved int he peptidoglycan cross linking in the bacterial cell wall…death from osmotic pressure induced cytoplysis
Small size allows it to penetrate deeply into the cell wall
Also activates autolytic enzymes inth e bacteria to cause cell death
Penicillin bacteriostatic or bactericidal
Bactericidal
Causes cell death
Side effects penicillin
Hypersensitivity
Immune mediated hemolysis due to a haten mechanism, which is when the antibodies target the combination of penicillin in Association with the rbc and activate complements to induce hemolysis and removal of rbc
Indications for penicillin
Gram positive (bc inhibit formation of peptidoglycan cross linking in the bacterial cell wall) Spirochetes-syphilis
MOA penicillin
Binds PBP(component of bacterial cell wall and involved in cell wall synthesis)
Blocks transpeptidase cross linking of the cell wall
Activates autolytic enzymes
Bactericidal
Side effect penicillin
Hypersensitivity Hemolytic anemia(immune mediated hemolysis of rbc via hapten mechanism in which antibodies are targeted against the combination of penicillin attached to rbc-> complement activation and removal of rbc by spleen)
Beta lactamse sensitive
Beta lactamase
Enzymes produced by some bacteria to cleave beta lactate antibiotics
Beta lactamase sensitive bacteria
Susceptible to cleavage by beta lactamase and are likely to be ineffective against beta lactamase producing bacteria
Aminopenicillin mechanisms
Beta lactam
Inhibit PBP
Bactericidal
Broader spectrum of activity than penicillin and are not degraded by acid hydrolysis and can be given orally
Are aminopenicillin beta lactamase sensitive
Yup
What are aminopenicillin given with to prevent beta lactamase isssues
Clavulanic acid-beta lactamase inhibitor
Indication for aminopenicillin
Most gram positive infections and some gram negative(e coli and H influenza)
Common aminopenicillin
Ampicillin and amoxicillin
Adverse reactions to aminopenicillin
Hypersensitivity Ampicillin rash (when given for mono) Pseudomembranous colitis
Indications for aminopenicillin
Some gram _(e coli and H influenza
Gram +
Ampicillin
Gram + and limited gram negative
Rash with mononucleosis
Amoxicillin
For otitis media, skin infections, and strep throat
Susceptible to beta lactamse producing bacteria so is combined with clavulanic acid
MOAaminopenicillin
Beta lactamase sensitive
Given with beta lactamase inhibits like clavulanic acid
Clavulanic acid
Beta lactamase inhibitor tha tis commonly combined with penicillin to overcome resistance
Suicide inhibitor-covalently binds to the active site of beta lactamase, thus inactivating it.
Commonly combined with amoxicillin and is called augmentin
Side effects aminopenicillin
Hypersensitivity
Ampicillin rash
Psudomembranous (with mono/EBV and ampicillin)
colitis(colon infection with foul smelling diarrhea, fever, and abdominal paid cause by c diff)
Ampicillin and amoxicillin
Broad spectrum penicillin antibiotics that work by inhibiting enzymes that are key in bacterial cell wall synthesis, eventually leading to cell lysis or rupture
What are ampicillin and amoxicillin effective against
Gram + and some gram -
NOT staph a, unless given with beta lactamase inhibitor
Indications for amoxicillin and ampicillin
Gram + (strep p, clostridium tetani) and some gram - (haemophilus influenza, E. coli, salmonella, and shigella)
Side effects ampicillin amoxicillin
Rash diarrhea (more in ampicillin than amoxicillin)
Take probiotics
Are amoxicillin and ampicillin good for staph a
No bc it has a beta lactamase
What are clavulanic acid and amoxicillin called together
Augmentin
What are ampicillin and sulbactam called together
Unasyn
Allergic reaction to ampicillin and amoxicillin
Rash to anaphylaxis(immediate or 30 min)
If have allergy history don’t give
When get ampicillin rash
If accidentally soused for patients with MONO
Amoxilccin indication
Otitis media, skin infections, strep throat.
Indications for aminopenicillin
Shigella Haemophilus influenza Salmonella Listeria Enterococci Proteus mirabilis E. coli
Antipseudomonal penicillins/carboxypenicillins
Have extra carboxylic acid group
Beta lactam
Bind PBP
Bactericidal
What do antipseudomonal penicillins work against
Gram negative organisms like pseudomonas a and proteus mirabalis
Antipseudomonal penicillins sensitive to beta lacatamase
Yup give with clavulanic acid
Common antipseudomonal penicillin
Ticarcillin
Carbenicillin
Piperacillin
Ticarcillin
Injectable used for pseudomonas infections
Carbenicillin
Limited coverage against gram +
Piperacilin
For pseudomonal infections
Given with tazobactam
IV or IM NOT ORAL
Side effects antipseudomonal penicillin
Hypersensitivity
