Spotlight on Antibiotics Flashcards
Urgent bacterial threats
Serious bacterial threats
Concerning bacterial threats and watch list
4 mechanisms of antibiotic resistance
Modifications of the Antibiotic Molecule
Decreased Antibiotic Penetration and Efflux
Changes in Target Sites
Resistance Due to Global Cell Adaptations
What are 4 antibiotic stewardship practices?
1.) to measure antibiotic prescribing
2.) to improve antibiotic prescribing by clinicians and use by patients so that antibiotics are only prescribed and used when needed
3.) to minimize misdiagnoses or delayed diagnoses leading to the underuse of antibiotics
4.) to ensure that the right drug, dose, and duration are selected when an antibiotic is needed
What kills sensitive organisms so that number of viable organisms fall rapidly after exposure
Bactericidal
What inhibits growth of bacteria but does not kill them?
Bacteriostatic
What type of antibiotic’s agent is active against a single species or limited group of pathogens?
narrow-spectrum
What type of antibiotic’s agent is active against a wide range of pathogens?
broad-spectrum
Which type of antibiotic’s agent falls in between (intermediate) narrow and broad?
extended-spectrum
Penicillin V: type, administration, adverse effects and what it treats?
Narrow-spectrum antibiotic
Typically administered in an oral suspension
Adverse effects include GI upset, nausea, vomiting, diarrhea, and rash. In rare instances can cause severe hypersensitivity reactions.
Considered the drug of choice for Group A streptococcal pharyngitis
Mechanism of action of antibiotics
All beta-lactam antibiotics interfere with bacterial cell wall synthesis
Inhibition of bacterial transpeptidase (also called penicillin-binding protein) which inhibits peptidoglycan cross-linking making cell wall synthesis impossible
Generally confers bactericidal activity
Penicillin V: Dose
Dosed by weight for adults and children
People over 27 kg: 300 mg TID or 600 mg BID PO for 10 days
People 27 kg or under: 40 mg/kg/day divided BID or TID for 10 days with a maximum daily dose of 750 mg.
Amoxicillin: type, side effects?
An extended-spectrum penicillin
Essentially a modified version of penicillin that results in greater activity against additional gram-negative bacteria
Generally well tolerated but can cause the same adverse effects as penicillin V
Typically used more often as it is more palatable than penicillin V
Amoxicillin dose.
Dosed by body weight for all patients
50 mg/kg once daily or divided BID PO for 10 days with a maximum daily dose of 1000 mg.
Cephalosporins class: type, structure?
A very large group of antibiotics
The different generations are used to define their antimicrobial spectrum
Have greater structural diversity which is more resistant to beta-lactamases and increases their range of antimicrobial activity
Cefadroxil: type, what it is used for, side effects.
A first-generation cephalosporin
May be used if treatment failure with penicillin or in individuals with nonimmediate hypersensitivity to penicillins
Adverse effects include GI upset, nausea, vomiting, diarrhea, hypersensitivity (some cross-reactivity with penicillins)
Cefadroxil dose
Adults: 1 g/day PO as a single dose or divided BID for 10 days
Cephalexin: type, side effects
A first-generation cephalosporin
Adverse effects include GI upset, nausea, vomiting, diarrhea, hypersensitivity (some cross-reactivity with penicillins) and may also be used if treatment failure with penicillins or in individuals with nonimmediate hypersensitivity to penicillins
Also available as a suspension
Cephalexin dose.
Adults: 500 mg BID PO for 10 days
Children: 40 mg/kg/day divided BID PO for 10 days with a maximum daily dose of 1000 mg.
Protein synthesis inhibitors
Prokaryotic ribosomes are composed of a 30S and 50S subunit
Eukaryotic mRNA translation proteins are far more complex than those in prokaryotic cells
What do macrolides do? What does it interfere with?
Inhibit peptidyl transferase which functions to link amino acids together in the growing peptide chain
Also interferes with translocation (movement of the nucleotide from the A position to the P position to allow for reading the next spot on the mRNA)
Confers bacteriostatic activity
Azithromycin uses, side effects
An alternative for patients who are allergic to penicillin
Less likely than other macrolide antibiotics to interact with other drugs
Adverse effects include GI upset, nausea, vomiting, diarrhea, rash, QTc interval prolongation.
type of macrolide
Azithromycin dose, benefits?
Adults: 500 mg PO for one day, then 250 mg PO daily for 4 days
Children: 12 mg/kg PO for 5 days with a maximum daily dose of 500 mg
ONLY 5 days
