Antibiotics Flashcards
Azithromycin (Zithromax; Z-pak)
PO/IV
Macrolide
Clarithromycin (Biaxin)
PO
Macrolide
SE: GI upset
Erythromycin (E-Mycin)
PO/IV
Macrolide
little h.flu coverage
SE: GI upset, QT prolongation
Erythromycin 0.5% ointment
Macrolide - opthalmic
Prophylaxis opthalmia neonatorum
conjunctivitis (q 4-6 hrs)
Azithromycin 1.0% solution (AzaSite)
Macrolide - opthalmic
conjunctivitis >1 year old
dosing: bid then qd (more convenient than e-mycin)
Store in refrigerator
Beta-Lactams MOA
- Targets cell membrane
1. Inhibits the enzyme transpeptidase (pcn binding protein), causes lysis of the cell.
2. bacteriocidal
3. time dependent
Beta-Lactams - General uses
pharyngitis (esp. GABHS), prevention of rheumatic heart disease and syphilis
Neurosyphilis DOC
Aqueous PCN G
Aqueous PCN G
Beta Lactam Penicillin
IV/IM
Adult: 0.5-4 MU q 4 hrs
Peds: weight based
PCN VK
Beta Lactam Penicillin
only PO
Benzathine PCN G (Bicillin)
Beta Lactam Penicillin
IM
Adult: 2.4 MU x 1
*make sure has tolerated PCN before because the dose lasts a long time
Why should you not use PCN in staph cellulitis?
because staph produces penicillin-ase that neutralizes the drug (use PCN-ase resistant PCN instead)
Beta Lactams - side effects
anaphylaxis
rash
nausea
seizure
Penicillinase-Resistant PCNs - spectrum
NARROWED spectrum to staph (aureus and epidermidis)
mostly for cellulitis and endocarditis
Dicloxacillin (Dycill; Pathocil)
BL: PCNase resistant
PO (empty stomach)
QID
MSSA only
Nafcillin (Unipen)
BL: PCNase resisitant
IV (burns)
4-6 times a day
MSSA
Oxacillin (Bactocil)
BL: PCNase resistant
IV/IM
PCN-ase resistant
Used in Lab to test for resistance (MRSA)
Not used much b/c of SE (renal and liver)
Aminopenicillins - coverage
expanded gr-
“HELPS” - h.flu, e.coli, listeria, proteus, salmonella/shigella
Good activity against PCN-resistant strep pneumo
*Enterococcus
Aminopenicillins - General uses
OM, sinusitis, lower UTI, Shigella, Salmonella, h.pylori, listeria
Listeria (meningitis) DOC
Ampicillin
GBS prophylaxis for delivery DOC
Ampicillin or PCN
Ampicillin
Aminopenicillin
PO/IV q6
SE: rash (especially if give for viral/mono infection)
Renal dosing
Amoxicillin (Amoxil)
Aminopenicillin
PO q8
SE: rash (especially if given for viral/mono)
PO dosing provides better absorption and less frequent administration improves compliance
Shigella DOC
Ampicillin
Salmonella DOC
Amoxicillin
Extended Spectrum Penicillins (Beta Lactam) - spectrum
extended to cover pseudomonas and enterobacter
“Treats Pseudomonas”
Ticarcillin, Piperacillin
Beta Lactam/Beta Lactamase Inhibitor (BLI)
BLIs inhibit the enzymes that bacteria produce that inactivate the beta-lactam antibiotic. Given with some beta lactams to decrease resistance.
What are the 3 BLIs?
SUB - sulbactam
CA - clavulanic acid
TZ - tazobactam
Amoxicillin/CA (Augmentin)
Extended spectrum PCN
Only PO option (q 8-12)
renal dosing
*no pseudomonas
Ampicillin/SUB (Unasyn)
IV/IM q 6-8 Extended spectrum PCN *no pseudomonas Covers anaerobes Best of this group for enterococcus
What are the extended spectrum penicillins for enterococcus?
Ampicillin/SUB (Unasyn)
Ticarcillin/CA (Timentin)
Extended spectrum PCN
IV/IM q 4-8
Pseudomonas
renal dosing
Piperacillin/TZ (Zosyn)
Extended spectrum PCN
IV/IM q 4-6
pseudomonas
renal dosing
What are the extended spectrum penicillins for pseudomonas?
Ticarcillin/CA and Piperacillin/TZ
Cephalosporin (Beta Lactam) - general info
bacteriocidal
5 generations - each generation sees greater gr- coverage and CNS penetration
What 3rd generation cephalosporin common causes brick red or maroon stool?
Cefdinir (Omnicef)
What 3rd generation cephalosporin covers pseudomonas?
Ceftazidime (Fortaz)
Monobactams (Beta Lactam) - spectrum
“MONObactams only cover 1 type of bacteria which can be ‘negative’” (gram negative only)
Monobactams - general uses
UTIs, skin infections, pneumonia, intrabdominal infections, septicemia, gyn infections
Aztreonam (Azactam)
Monobactam
IV 1-2 g q 8-12 hrs
SE: phlebitis, rash, elevated liver enzymes
Carbapenems (Beta Lactam) - spectrum
multi-drug resistant pathogens and pseudomonas (except ertapenem)
Similar to 4th gen cephlasporins in coverage
Which carbapenem does NOT cover pseudomonas?
ertapenem
Carbapenems - general uses
UTIs, febrile neutropenia, soft tissue infections, bacterial meningitis (>3 mos old)
Carbapenems
imipenem (primaxin) IV
ertapenem (Invanz) IM/IV (no pseudomonas)
doripenem (doribax) IV
meropenem (merrem) IV/IM
SE: up to 50% of pts allergic to PCN are allergic to carbapenems
renal dosing
Vancomycin - IV or PO?
PO for c.diff only (doesn’t absorb - too big!)
IV for MRSA
Vancomycin - C.diff treatment
wash hands with soap/water, alcohol does not kill #1 Metronidazole 500mg po tid x 10-14 days (for 1st/2nd mild-moderate infections) #2 Vancomycin 125 mp PO qid x 10-14 days (severe infection) #3 vancomycin 500 mg po qid for servere +/_ metronidazole IV (if inflaned colon or complete ileus)
Telavancin (Vibativ)
IV
Lipoglycopeptide
complicated skin and skin structure infections (cSSSI) caused by: MRSA, strep pyogenes, strep agalactiae, enterococcus faecalis)
renal dosing
SE: taste disturbances (soap/metal), nephrotoxic, QT prolongation
Preg C but there is concern
Expensive
Macrolides and Ketolide MOA
inhibit protein synthesis by binding to domain II and V on the ribosomal subunit
Telithromycin (Ketek)
PO
Ketolide
s.pneumoniae, CAP, bronchitis, sinusitis, s.aureus, h.flu, atypicals
CYP3A4 inhibitor
renal adjust
hepatotoxic
*Lots of issues: FDA, renal dosing, side effects –> not used much anymore
Tetracyclines - MOA
bind to the 30S ribosomal subunit and interfere with translocation reaction
Tetracyclines - general uses
Anthrax, CAP, acne, tick born diseases
Tetracycline (Sumycin)
PO
SE: yellowing teeth/decreased bone growth in peds, phototoxicity, GI, esophageal ulcerations
di and trivalent cations decrease absorption
Minocycline (Dynacin; Minocin; Solodyn)
PO (empty stomach)/IV Tetracycline ADE: blue gray staining of teeth CA-MRSA renal adjust di and trivalent cations reduce absorption
What is the Preg category for all tetracyclines?
D
Doxycycline (Vibramycin)
PO/IV Tetracycline MRSA *no renal adjustment phototoxicity
What is the only tetracycline that does not require renal adjustment?
Doxycycline
What class of drugs is used to treat tick borne illnesses like Lyme and RMSF?
Tetracyclines
Which antibiotics (general) cover gr+?
All except tetracyclines and metronidazole