Antibiotic Overview (Spectrum + ADRs) Flashcards
What bacteria are GP organisms?
Staphylococcus, Streptococcus, oral Anaerobes (Clostridium, Peptostreptococcal), Enterococcus
What bacteria are GN organisms?
Anaerobes (Bacteroides), E. coli, Klebsiella, Proteus, Pseudomonas, Moraxella, N. gonorrhea, N. meningitidis, H. influenzae, ESCAPPM (SPICE/SPACE
What are atypical bacteria?
Legionella, Mycoplasma, Chlamoydophila
What are the beta-lactams?
Penicillins, cephalosporins, carbapenems
What is the ABX spectrum of PEN V/G? How do you take them?
GP streptococci, E. faecalis, GP anaerobes (oral), GN cocci/coccobacilli (N. meningitidis, Treponema pallidum; syphilis)
Pen VK (300-600mg q6-8h): take without food (1-2 hours before a meal), N/V/D, abdominal pain, rash, oral candidiasis
PEN G (IV)
What is the ABX spectrum of Cloxacillin? How do you take it?
considered 2nd generation penicillins, are penicillinase-resistant and have activity against those above (plus resistant forms), PLUS S. aureus (approved for the treatment of penicillinase-producing staphylococci)
take without food (at least one hour before meals), or take with food if stomach upset, N/V/D, flatulence, abdominal pain
What is the ABX spectrum of Amoxi-Clav? How do you take it?
ES + beta-lactamase inhibitor to provide additional coverage against resistant forms (MSSA, all anaerobes, GN beta-lactamase stable; Moraxella, Klebsiella)
500/125mg q8h OR 500/125 – 875/125 q12h: take with or without food (better with food), N/V/D (D worse with clav), yeast infections, black hairy tongue, teeth discolouration
What is the ABX of amoxicillin/ampicillin? How do you take it?
aminopenicillins that provided extended spectrum (additional coverage against E. coli, H. influenzae, Proteus)
Amoxicillin (500-1000mg q8-12h): with or without food, N/V/D, headache, rash
What is the ABX of piperacillin + piptazo? How do you take it?
ES Penicillin with increased GN coverage compared to amoxicillin (i.e., + Citrobacter, Acinetobacter, Pseudomonas, Enterobacter, Serratia)
Piperacillin-Tazobactam (IV): ES + beta-lactamase inhibitor (similar coverage to Amoxicillin-Clavulanate + Piperacillin coverage), ADRs as above (without GI side effects, except increased risk of C. diff)
What is a true penicillin allergy?
Immediate reactions usually begin within 1 hour of the last administered dose and may begin within minutes, although if the dose was given orally or with food, it may occur within six hours of the administered dose. However, in these cases, allergic sensitization first develops then initial symptoms appear during the treatment and escalate rapidly with any successive doses.
o Itching, flushing, hives, angioedema, bronchospasm, hypotension, abdominal distress
o Requires a penicillin skin test
What are the side effects and interactions associated with beta-lactams?
ADRs: N/D, C. diff, allergic reactions, injection site reactions
DDI: may increase INR, OC failure
What are the antibiotic spectrums with each generation of cephalosporins? How do you take them?
1st generation (Cefadroxil PO, Cephalexin PO, Cefazolin IV): GP streptococcus, MSSA, GN N. meningitidis, H. influenzae, bacilli; E. coli, Proteus, Klebsiella
* Cephalexin: take with food, don’t crush
2nd generation (Cefprozil PO, Cefuroxime PO/IV, Cefoxitin IV): as above PLUS resistant forms (increased S. pneumo, H. influenzae, Neissera but decreased S. aureus,), extended spectrum against GP anaerobes (oral), GN Moraxella
* Cefuroxime poor BA
3rd generation (Cefixime PO, Cefotaxime/Ceftriaxone IV): increased GN coverage to cover N. gonorrhoeae, GP coverage against S. pneumo (Cefotaxime/Cefriaxone only!!!!)
Ceftazidime [3GC]: GN coverage only to include Pseudomonas, Acinetobacter, no Neisseria coverage
4th GC (Cefepime IV): Ceftazidime coverage + 2nd generation coverage (GP PLUS GN, MRSA)
5th GC (Ceftobiprole/Ceftaroline IV); GP + GN coverage PLUS MRSA, no Acinetobacter
What is the ABX spectrum for carbapenems?
GP Streptococcus, S. aureus, E. faecalis* (not E. faecium), both oral anaerobes and Bacteroides
GN cocci/coccibacilli/bacilli*: ESCAPPM, SPICE/SPACE
*Ertapenem has no coverage against E. faecalis (intrinsically resistant) and Pseudomonas
Define macrolides: ABX spectrum + ADRs
function to inhibit the 50S ribosome (bacteriostatic).
ADRs: GI upset, LFTs, insomnia, QTc (C = E > A), ototoxicity (reversible, dose-related), caution in myasthenia gravis (muscle weakness), increased risk malformations vs. penicillins in 1st semester
*higher doses do not overcome S. pneumo resistance
Macrolides (Erythromycin PO/IV, Clarithromycin PO), Azalide (Azithromycin):
GP (variable), Streptococcus (not PRSP), MSSA
GN H. influenzae, atypical pathogens (Mycoplasma, Legionella, Chlamydophila)
- Erythromycin (lacks H. influenzae): take with or without food (better without, but high GI upset), ERYC formulation can be sprinkled in food, estolate formulation CI in pregnancy but best in kids as most acid stable
o CYP 3A4/PGP-inhibitor
- Clarithromycin: CYP 3A4 & Pgp-inhibitor
- Azithromycin: long half-life (AKA 5 day duration; 500mg x 1 –> 250mg OD x 4 days), leads to more resistance than clarithromycin, anti-inflammatory activity (AECOPD, efficacy limited)
Define the tetracyclines (spectrum + ADRs)
Inhibits 30S ribosome (bacteriostatic)
Doxycline, Minocycline, Tetracycline (all PO)
GP variable Streptococcus, S. aureus (+ MRSA)
GN broad (but not Psudomonas)
atypical respiratory pathogens (Mycoplasma, Chlamoydophila, Legionella)
Protozoa
ADRs: gastrointestinal problems, teeth staining in kids, and sun sensitivity
