35/36: Antibiotics - Smith Flashcards
spectrum of activity for Pen G
- Streptococcus Group A and B
- Group D Streptococcus (enterococcus)
- Anaerobes, except Bacteroides
- Gonococci
- Staphylococcus less than 10%
often used for ear infections
amoxicillin/ampicillin
spectrum of activity for amoxicillin/ampicillin
- Streptococcus, including Group D
- Some gram negative coverage (E. coli, H. influenzae, P. mirabilis, Salmonella and Shigella)
- Most Staphylococcus resistant
- Bacteriostatic unless combined with Aminoglycoside
CONDM anitbiotics
semisynthetic penicillins Cloxacillin oxacillin nafcillin dicloxaillin methicillin
(penicillinase-resistant)
what metabolizes nafcillin
liver
- covers staph, except MRSA
extended-spectrum penicillins and beta-lactamase inhibitors common combinations
- Ticarcillin / Clavulanic Acid (Timentin)
- Ampicillin / Sulbactam (Unasyn)
- Amoxicillin / Clavulanic Acid (Augmentin)
which drugs have a high sodium load?
- ticarcillin/clavulanic acid (timentin) [120 mg/g sodium load]
- ampicillin/sulbactam (unasyn)
*** do two 250 mg augmentin oral tabs = 1 500 mg augmentin tab
NO
- because all pills contain 125 mg of clavulanic acid
- too much clavulanic acid causes GI side effects
how does unasyn compare to timentin?
- more active against gram + than timentin
- less active against gram - than timentin
describe the different generations of cephalosporins
First Generation-Better activity against gram positive cocci
Second Generation-Less activity against gram positive, but more activity against gram negative organisms
Third Generation-Even less activity against gram positive, more activity against gram negative organisms
Fourth Generation-Best of both worlds (gram + and - )
common oral 1st gen cephalosporin
cephalexin (keflex, keftab, keflet)
common parenteral 1st gen cephalosporin
cefazolin (ancef, kefzol)
classify this drug: cephradine (anspor, velosef)
1st or 2nd gen cephalosporin
- not super common
20% pen-allergic patients are also allergic to…
cephalosporin
drug of choice for surgical prophylaxis
cefazolin
- 2g 30 min before surgery
elimination of ceftriaxone
biliary elimination
drug of choice for n. gonorrhea ***
ceftriaxone
longest half-life of any cephalosproin
ceftriaxone
gram + diplococcus is typically …
n. gonorrhea
elimination of cefoperazone
biliary elimination
elimination of cefepime
renal excretion
polymicrobial infection with renal insufficiency first choice
cefepime (4th gen cephalosporin)
why is cilastatin added to imipenem?
- imipenem is destroyed in kidney; cilastatin inhibits renal enzymes preventing degradation
“gorillamycin”
imipenem/cilastatin (primaxin)
- very broad spectrum
indications fro invanz/ertapenem [carbapenem]
anaerobic (gas gangrene, etc)
name the aminoglycosides
gentamicin (garamycin)
tobramycin (nebcin)
amikacin (amikin)
spectrum of activity for aminoglycosides
- Gentamicin best activity against Serratia
- Tobramycin best activity against P. aeruginosa
- Amikacin reserved for organisms resistant to other two
adverse reactions aminoglycosides
nephrotoxicity, ototoxicity, neuromuscular blockade
aminoglycosides are always infused over _____ minutes
- 30
- neuromuscular blockade is risk with rapid admin
what do you do when peak is high and trough is normal?
Peak high and trough normal - decrease dose
Peak low and trough normal - increase dose
Peak normal and trough high - increase time
Peak normal and trough low - decrease time
name the most common antianaerobic agents
metronidazole (flagyl)
clindamycin (cleocin)
adverse rxn metronidazole
metallic taste disulfiram reaction (alcohol reaction)
treatment of pseudomembranous colitis
#1 metronidazole (oral) or #2 vancomycin (oral) *** never put pt on anti-GI motility drug if they have this condition (want the bad to come out)
causes pseudomembranous colitis (antibiotic associated diarrhea)
clindamycin (because doesn’t work against c. diff)
metabolism of metronidazole
liver
- clindamycin is also metabolized by liver
can kill MRSA, MRSE, and enterococci
vancomycin
red man syndrome
- adverse effect of vancomycin
- should give over 45-60 min to prevent
- peak less than 30ml/min and trough less than 10 ml/min
turns body fluids red (contact lenses) and a rash
rifampin
only use for oral vancomycin
pseudomembranous colitis
used for TB
rifampin
- always in combo with other drugs
name the quinolones we might use
- CIPROFLOXACIN (CIPRO)
- LEVOFLOXACIN (LEVAQUIN)
- TROVAFLOXACIN (TROVAN) (only life-threatening infections)
does ciprfloxacin cover streptococcous?
no
- Excellent coverage against gram negative organisms, including Pseudomonas
- Mild Staphylococcus and no Streptococcus coverage
adverse reactions with cipro/ciprofloxacin
- Theophylline and derivatives (caffeine) will be potentiated
- Antacids and Fe will decrease absorption
- Cartilage degeneration and tendon rupture (*do not use on juvenille pts - premature growth plate closure)
which antibiotic might cause an achilles tendon rupture?
quinolones class
Similar indications as Ciprofloxacin (Cipro), but dosage is once a day
levaquin
what is bactrim?
trimethoprim/sulfamethoxazole
1:5 ratio
name the macrolides
- ERYTHROMYCIN (E-MYCIN, EES, ERYTHROCIN)
- AZITHROMYCIN (ZITHROMAX/ Z-PAK)
- CLARITHROMYCIN (BIAXIN)
Z-PAK?
azithromycin 5 days of therapy
2 - 250 mg first day
1 each day from days 2 through 5
can macrolides be used for pen-allergic pts?
yes
drug of choice borrelia burgdorferi/ lyme disease
tetracyclines
side effects of tetracycline
sun sensitivity and graying of teeth
why is linezolid a good drug?
- no dose adjustment for renal impairment
- works against Strep. D (VRE), Staph. aureus (MRSA), Staph. epidermidis (MRSE), Pasteurella multocida
