Flashcards in Aminoglycosides, tetracyclines, flagyl, bactrim and tigecycline Deck (41):
Gentamysin, tobramycin, amikacin, streptomycin, neomycin
MOA of aminoglycosides
actively transported across cytoplasmic membranes into the interior of the bacterial cell, requires energy, o2 and a higher pH, bind to 30S ribosome inhibiting protein synthesis
PK of aminoglycosides
bactericidal activity, and concentration dependent, IV only, also IM, IT, intraventricullarly, inhaled and topical, 100% renaly eliminated, wt based dosing
Spectrum of activity of aminoglycosides
aerobic, gram negative rods, enterobacteriaceae, S. Aureus- not monotherapy
What is generally considered best option for GNR?
In what bacteria is gentamycin used for synergistic purposes?
What is reserved for tobramycin and gentamycin resistant?
Clinical use of aminoglycosides?
only use monotherapy for UTI, gram- sepsis, HCAP, bacteremia, gram+ synergy
What should aminoglycosides not be used for?
ADRs of nephrotoxicity
Nephrotoxic and ototoxic; usually develops 5-7 days after therapy, generally milk AKI and reversible
What does it mean if a pt develops drop in creatinine after start of aminoglycoside therapy
It may just be to course of disease--- not therapy, because it takes 5-7 days for there to be negative affect on kidneys from the therapy
Trimethoprim/Sulfamethoxazole (Bactrim) typical form?
used as double strength, 1 tab PO BID, 400, 800 mg
MOA of bactrim?
inhibits sequential steps in folate synthesis of susceptible organisms, bacteriostatic when alone, but combined is bactericidal
Spectrum of bactrim?
aerobic gram+, staph (MRSA and MSSA, CA not HA), strep- resistance increasing, listeria monocytogenes, nocardia- DOC, Aerobic gram -, e.bacteriaceae- resistance inc, M. catarrhalis, H. influenza, s.maltophilia, b. cepacia, p. jiroveci
What is Bactrim DOC for?
nocardia, burkholderia cepacia, pneumocystis jiroveci
What does bactrim not cover?
IV and PO, renally eliminated, DI w/ warfarin (should dec warfarin dose by 50%)
when on bactrim IV, what should be done?
concurrent fluid administration- 2 L/day
ADRs of Bactrim?
N/V/D, anorexia, hematologic, hyperkalemia
Clinical use of bactrim
CA- MRSA SSTI, UTI- resistance worsening, PSP p. jiroveci, nocardia infections DOC- requires very high dose, pyelonephritis, prostatitis
What is bactrim DOC for?
nocardia infections with high doses, and PCP P. jiroveci
What are the tetracyclines?
doxycycline (Vibramycin), ,tetracycline, minocycline (Minocin)
What is the dose of doxycycline?
100 mg PO BID
MOA of tetracyclines?
binds to 30 s ribosome to inhibit RNA-dependent protein synthesis, bacteriostatic
Spectrum of tetracyclines?
gram +, staph, strep- not PCN resistant, e.bacteriaceae, h. influenzae, m. catarrhalis, tick bourne disease, acne vulgaris and borrelia burgdorferi
What is doxycylcine for?
CA-MRSA, and rickettsia
What is doxycycline and minocycline used for?
all the atypicals, legionella, mycoplasma pneu, chlamydophilia pneu
What forms of tetracyclines are available?
All po, doxy and minocycline are available IV
ADRs of tetracyclines?
N/V/D, photosensitivity, dec oral contraceptives, discoloration of teeth, dec bone development
Clinical use of tetracycline?
CA-MRSA- doxy, chlamydia, lyme disease, PID-Doxy, rocky mountain spotted fever, acne- minocycline, atypical infections
Tigecycline (Tygacil) MOA
a glycylcycline, inhibits protein synthesis, bacteriostatic, IV only
Spectrum of activity of tigecylcine?
aerobic Gram +, MSSA, MRSA, strep- multidrug resistant s. pneu, enterococci- VRE, very broad spectrum gram -, drug resistant e. bacteriaceae, carbapenem resistant, anaerobes, atypicals, good for abd infections
What is tigecycline not good for?
proteus or pseudomonas
Tigecycline (Tygacil) clinical use
complicated SSTI, intra-abd, culture proven pan-resistant pathogens
ADRs of tigecycline (Tygacil)
N/V/D- significant, use cautiously if tetracycline allergy, photosensitivity, discoloration of teeth
Metronidazole (Flagyl) MOA
binds to and disrupts DNA and nucleic acid synthesis, bactericidal, conc dependent
Dose of flagyl
500 mg PO/IV TID-QID
Spectrum of activity of flagyl
only anaerobic , gram -: bacteroides, fusobacterium, prevotella, C. dif, trichomonas vaginalis, giardia lamblia
N/V/D, metallic taste, pancreatitis, CNS complications, disulfiram rxns- avoid w/ EtOH
What should be done if people on flagyl develop CNS sx
must d/c therapy, seen w/ large doses or prolonged therapy, peripheral neuropathy, , seizures, confusion, ataxia, vertigo