Antimicrobials: Sulfas, Nitros, Oxals, and Lipos Flashcards
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Nitroimidazoles: Metronidazole
MoA
enters the cell, then is reduced to free radicals which damage bacterial DNA.
Nitroimidazoles: Metronidazole
bacteriocidal or static?
cidal.
Nitroimidazoles: Metronidazole
dose adjustment
no need for hepatic or renal adjustment
Nitroimidazoles: Metronidazole and ANY form of alcohol
Disulfiram reaction due to effect on alcohol dehydrogenase, alcohol cannot be broken down.
Nitroimidazoles: Metronidazole and warfarin
increased INR
Nitroimidazoles: Metronidazole pt education
absolutely no alcohol, not even mouthwash with alcohol
also tastes horrible
Nitroimidazoles: Metronidazole coverage
ANAEROBES
Nitroimidazoles: Metronidazole
activity
not active against most gram pos or neg because it does not provide aerobic coverage
active against all anaerobes including c. diff
Nitroimidazoles: Metronidazole and h pylori
active against
Nitroimidazoles: Metronidazole AE (5)
poor taste GI disturbance reversible neutropenia dark urine rash
fever of unknown origin: treatment (3)
cover MRSA - vanco
cover anaerobes - metronidazole
everything else, including psuedomonas - cefepime
Oxalinediones: linezolid
MoA
Binds to 50S ribosomal subunit, inhibits the early phase of protein synthesis.
Oxalinediones: linezolid
bacteriostatic or bacteriocidal?
bacteriostatic
Oxalinediones: linezolid was made to
combat increasing resistance against vancomycin
Oxalinediones: linezolid
activity
gram positive pathogens:
enterococci faecium and faecalis which are vanco sensitive and resistant organisms
staph: MRSA and MSSA
strep: including PCN resistant strains
Oxalinediones: linezolid
when may you expect to see it?
if you cannot use vanco because of allergy, resistance, or issues with levels
Oxalinediones: linezolid AEs
diarrhea/nausea
taste
inc LFT
thrombocytopenia
Oxalinediones: linezolid should be reserved for
patients who cannot be helped by vanco
otherwise it is a very expensive drug
lipopeptide drug
daptomycin
lipopeptide (daptomycin) MoA
binds to bacterial cell membranes causing rapid depolarization of membrane potential, leading to inhibition of protein/dna/rna synthesis and ultimately bacterial cell death
lipopeptide (daptomycin) is bacteriostatic or bacteriocidal?
bacteriocidal
lipopeptide (daptomycin) gram positive activity:
streptococci
s epidermidis
enterococci (VRE*)
S aureus (MSSA, MRSA, GISA, GRSA)
lipopeptide (daptomycin) is the first bacteriocidal drug against
gram positive organisms
lipopeptide (daptomycin) distrubution
everywhere EXCEPT lungs
why is lipopeptide (daptomycin) ineffective for pneumonia?
it cannot get through the surfactant in the lungs
lipopeptide (daptomycin) adverse event and implication
increase in CK
get CK at baseline and then weekly as long as the patient is on the drug.
could become rhabdomyolysis
lipopeptide (daptomycin) and renal insufficiency
dose reduce
Sulfas, Nitros, Oxals, and Lipos
monitoring
C&S
CBC
RFT
dap: CK
Sulfas and Linezolid
pregnancy/lactation
C
metronidazole and daptomycin pregnancy category
B
Daptomycin lactation consideration
excreted in milk
daptomycin and MAOIs
myopathy
dosing daptomycin: obesity
actual weight
Sulfa drug
bactrim: trimethoprim/sulfamethoxazole
MoA: bactrim (trimethoproim/sulfamethoxazole)
trimethoprim: folic acid antagonist, starves organism
sulfamethoxazole: inhibition of bacterial cell growth by inhibiting purine synthesis.
distribution of sulfas (bactrim)
widely distributed, but CSF levels are just about 40%
sulfas (bactrim) are one of the few PO drugs for
MRSA cellulitis
patient/clinician education regarding sulfas (bactrim)
need to be adequately hydrated because crystalluria can form.
drug interaction: sulfa (bactrim)
will increase activity of warfarin or phenytoin because it displaces it from protein binding sites. may need to dose them down.
sulfas (bactrim) and electrolytes
can cause hyperkalemia as it can block the excretion of potassium
sulfas (bactrim) and renal function
likely to bump up creatinine- check BMP
avoid in dialysis patients
Sulfas (Bactrim) activity: gram neg aerobes
good
sulfas (bactrim) activity for gram pos aerobes
good
sulfas (bactrim) and MRSA
moderate activity against MRSA
Sulfas (bactirm) and anaerobes
no coverage
PCP pneumonia and sulfas (bactrim)
effective against this opportunistic infection.
sulfas (bactrim) in HIV patients
prophylaxis for PCP and toxoplasmosis.
3x a week
not enough to elicit resistance
sulfas (bactrim) GI AE
GI intolerance
Sulfas (bactrim) and hypersensitivity
stevens-johnsons syndrome
Sulfas (bactrim) AEs: lab values (4)
anemia
neutropenia
hyperkalemia
elevated serum creat
If a patient tells you they have a bactrim allergy
do not give, especially if it was a skin reaction.
t 1/2 of sulfas (bactrim)
9-11 hours
dose 2x/day
dose adjustment for sulfas (bactrim)
CrCl < 15mL/min
