Antibiotics Flashcards
How would you dose a time-dependent killing drug?
Dose it often, has a minimal post-antibiotic effect
How would you dose a concentration-dependent killing drug?
Increase the dose all at once
Examples of time-dependent drugs
All B-lactam agents
Examples of concentration-dependent drugs
Aminoglycosides and Fluoroquinolones
What does synergistic drug effects mean?
Antibiotics given together that enhance the efficacy of a drug
Example of synergistic drug
Sulfamethoxazole/Trimethoprim (Bactrim)
What are the two PCN resistance methods?
- B-lactamase enzymes inactivate the antibiotic
2. Modification of the target PBP/ low or decreased affinity for Penicillin binding protein
Which organisms typically are effected with beta-lactamase enzymes?
Gram - organisms and staph aureus
How do you overcome the b-lactamase enzymes?
Co-formulate with b-lactam inhibitors
How do you overcome the extended spectrum beta-lactamase (ESBL)?
Give Carbapenems
How to overcome resistance when the PBP site is changed
Switch to an agent covering MRSA, or give high dose drugs (amoxicillin as example)
If you have a MRSA or strep pneumoniae resistance what do you do?
Change antibiotics
What are the two antibiotics in the NPCN class?
PCN G (IV) PCN VK (PO)
What do the natural penicillins cover?
Strep, VSE, Anaerobe (Peptostreptococcus)
What is a common indication for the NPCNs?
Dental infections, throat infections
What are the examples of Penicillinase resistant antibiotics?
Nafcillin (IV)
Oxacillin (IV)
Dicloxacillin (PO)
What do the penicillinase resistants cover?
MSSA (GREAT), Strep
What is a common indication for the penicillinase resistants?
Skin infections, MSSA infections including endocarditis
What are the examples of AminoPCNs?
Ampicillin (IV)
Amoxicillin (PO)
What do the AminoPCNs cover?
Strep, VSE, Anaerobes (Peptostreptococcus), +/- GNR, +/- H.flu M.Catarral
What are common indications for the AminoPCNs?
Otitis media, UTIs/URIs
Meningitis (Ampicillin)
Listeria (Ampicillin GOLD STANDARD)
What are the example of the Amino+BLIs?
Augmentin (Clavulanic acid, PO)
Unasyn (Sulbactam, IV)
What do the Amino+BLIs cover?
MSSA, Strep, VSE, Anaerobe (pepto), GNR, H.flu M.catarral, GN Anaerobe (bacteroides)
EVERYTHING EXCEPT PSEUDO MRSA and ATYPICALS
What are common indications for the Amino+BLIs?
Human bites, animal bites (Augmentin)
Broad empiric coverage, H-A infections, B-lactamase producing organisms
What is the antipseudomonal?
Piperacillin-Tazobactam (Zosyn) IV
What does Zosyn cover?
Everything except MRSA and ATYPICALS
What is the gold standard for PCN sensitive enterococcus?
Ampicillin
What else can Unasyn cover?
Acinetobacter
What can you do for a Strep pneumoniae resistance for Otitis media?
Can give high dose Amoxicillin, then change class if still not working
Which drugs are in the 1st generation cephalosporins?
Cefazolin (IV)
Cephalexin (PO)
Cephadroxil (PO)
What do the 1st generation cephalosporins cover?
MSSA, Strep, GP Anaerobe (pepto), +/-GNR
What are some common indications for the 1st gen cephalosporins?
2nd line for MSSA, SSTIs, UTI, Pre-op Abx
Which drugs are in the 2nd generation cephalosporins?
Cefoxitin (IV considered abd)
Cefotetan
Cefuroxime (IV considered resp)
Cefprozil
What do the 2nd gen cephalosporins cover?
MSSA, Strep, GP Anaerobe (pepto), GNR, +/-HNM
What does Cefoxitin cover that Cefuroxime does not? (2nd gens)
+/- coverage for GN Anaerobe Bacteroides Fragilis
What are the common indications for 2nd gen cephalosporins?
Respiratory tract infections, abdominal infections, GYN infections
Which drugs are in the 3rd gen cephalosporins?
Ceftriaxone IV Cepodoime PO
Ceftazadime (IV)
What is the coverage for 3rd gen cephalosporins?
MSSA, Strep, GP Anaerobe (pepto), GNR, HNM
What else does Ceftazadime cover that Ceftriaxone does not (3rd gen)?
+/- MSSA, also covers pseudomonas
What is the 4th gen cephalosporin?
Cefepime (IV)
What does Cefepime (IV) cover?
MSSA, Strep, GP Anaerobe (pepto), GNR, HNM, Pseudomonas
What is a common indication for 3rd gen cephalosporin?
CAP, meningitis, lyme
Gonorrhea: Ceftriaxone
Hospital acquired pneumonia: Ceftazadime
What is a common indication for Cefepime (IV)?
Hospital-acquired infections, neutropenic fever
What is the 5th gen cephalosporin?
Ceftaroline (IV)
What does Ceftaroline (Iv) cover?
MSSA, Strep, GP Anaerobe (pepto), GNR, HNM, MRSA
What is a common indication for Ceftaroline (IV)?
Skin and sin structure infections, MRSA and VSA infections
Do cephalosporins cover enterococcus (VSE) infections?
NO
Which 2nd gens are used for respiratory infections?
Cefuroxime, Cefaclor, Cefprozil
Which 2nd gens are used for abdominal/GYN infections?
Cefoxitin, Cefotetan
What are the 4 fluoroquinolones?
Ciprofloxacin, Levofloxacin, Moxifloxacin, Ofloxacin
What is the spectrum for fluoroquinolones?
Excellent atypical coverage (chlamydia, legionella, mycoplasma)
What are the common indications for fluoroquinolones?
Respiratory tract infections (except cipro)
UTIs (except moxi)
Intra-abdominal infections, osteomyelitis
What does Ciprofloxacin cover?
+/-MSSA and Strep, GNR, HNM, Pseudomonas, ATYPICALS
What does Levofloxacin cover?
MSSA, Strep, GP Anaerobe (pepto), GNR, HNM, Pseudomonas, ATYPICALS
What does Moxifloxacin cover?
MSSA, Strep, GP Anaerobe (pepto), GNR, HNM, +/- Bacteroides, ATYPICALS
What are carbapenems also called?
Gorilla-cillins
What are carbapenems the DOC for?
Ceftriaxone-resistant E.coli, Klebsiella, P.mirabilis (ESBL), complicated UTI, intra-abdominal infections
What are the 4 carbapenems? (IV only)
Impenem/cilastatin (Primaxin)
Meropenem (Merrem)
Doripenem (Doribax)
Ertapenem (Invanz)
What is the coverage for carbapenems?
MSSA, Strep, GP Anaerobe (pepto), GNR (entero), HNM, Pseudomonas (except Ertapenem), GN Anaerobe (B.fragilis)
What is an important ADR about carbapenems?
Higher risk of seizures with imipenem at high doses
What does Monobactam cover? (Aztreonam IV)
GNR and respiratory organisms and pseudomonas
What do you do if pt has anaphylaxis to beta-lactams?
Switch to a different class of antibiotics
What do you do if pt has a rash to a PCN?
Can consider a cephalosporin w/decreasing levels of cross reactivity or carbapenem
Can you use aztreonam if pt has a rash to PCN?
Yes, unless Ceftazidime allergy
What are important ADRs associated with fluoroquinolones?
Cant give to pregnant or children, FDA BBW for tendonopathies especially in elderly and children, prolongs Cumadin levels
What are the Macrolides?
Erythromycin, Clarithromycin, Azithromycin
What is the coverage for macrolides?
+/- MSSA Strep and GP Anaerobes, HNM, Atypicals
Cover for respiratory Gram -s
What are the common indications for macrolides?
Respiratory tract infections, alternative for PCN-allery (otitis media, pharyngitis), Chlamydia, Travelers diarrhea
What is important to note about macrolides?
NOT used for sepsis, urine or soft tissue infections!! Cause QTc prolongation
What are the tetracyclines?
Doxycycline, Tetracycline, Minocycline, Tigecycline
What are the common indications for tetracyclines?
Respiratory tract infections, MRSA skin and soft tissue infections, Tick-borne infections
What are some ADRs with tetracyclines?
Not indicated for children less than 8 or pregnancy. Cause tooth discoloration, GI esophagitis, photosensitivity
What is the coverage for tetracyclines?
MSSA, MRSA, +/- Strep, GP Anaerobes, HNM, Atypicals
What else does Tigecycline (IV) cover that other tetracyclines do not?
GNR, B.fragilis
