Tuberculosis - EG Flashcards
Which bacteria causes TB?
mycobacterium tuberculosis
silent, latent, progressive/active disease
What ages have 2-5x greater risk for active dz compared with other age groups?
kids younger than 2y/o and adults older than 65y/o
what are the 2 most important drugs in the tx of TB?
Isoniazid and rifampin
directly observed treatment (DOT) should be used…
whenever possible to reduce tx failures and the selection of drug-resistant isolates
What are 2 ways to test for TB?
Mantoux test –> tuberculin PPD skin test read in 48-72 hrs
IGRA –> measures release of INF-y in blood in response to TB antigens
What factors contribute to the new epidemic of TB?
increased incidence among prison inmates IV drug abusers immigrants HIV pts increasing numbers of young minority adults
TB symptoms…
fatigue, weight loss, fever, night sweats, and productive cough
What is required for treating active TB disease?
combination chemotherapy
at least two drugs to which the isolate is susceptible
generally, 4 drugs given at the onset of tx
(isoniazid, rifampin, pyrazinamide, ethambutol)
What are the best drugs for preventing drug resistance?
rifampin and isoniazid followed by
ethambutol, treptomycin, & pyrazinamide
Monotherapy can be used only for…
infected pt’s who do not have active TB (aka Latent infx)
What are the dosing recommendations for adults w/ reduced renal function and for receiving hemodialysis?
Pyrazinamide, ethambutol, and levofloxacin require a change in frequency — 3x per wk not daily
Pt’s with proved or strongly suspected active TB should get tx’d w/ isoniazide, Rifampin, pyrazinamide, and ethambutol for…
2 months
Patients w/active TB re-evaluated after 2 months of tx should have…
a repeat smear and culture
What drugs are the treatment options for latent TB?
isoniazid and rifampin
What is the first line tx for active and latent TB?
Isoniazid (INH)
Isoniazid (INH) MOA?
inhibits synthesis of mycobacterial cell walls
Isoniazid (INH) ADE’s?
peripheral neuropathy: vitamin B6-pyridoxine
& hepatoxicity
Rifampin will turn…
body fluids orange
Rifampin MOA
inhibits DNA-dep RNA polymerase –> blocking production of RNA
What parameters would you monitor for a pt on isoniazid?
LFT monthly if preexisting liver dz or abnormal fx
dosage adjustments for pt’s on anticonvulsants or warfarin
Rifampin ADE’s
turns body fluids orange color
cholestasis (hepatitis)
flu-like syndrome w/intermittent dosing
nephritis
What are 2 other rifamycins?
rifabutin –> fewer drug interactions
rifapentine –> long acting, given once weekly
What lab tests should you order to monitor pt on Rifampin?
liver enzymes and interacting drugs (ie warfarin)
Pyrazinamide ADE’s
*hyperuricemia hepatotoxicity rash GI disturbance arthralgias
Ethambutol is given until…
drug sensitivities are known
Ethambutol MOA
inhibits mycobacterial cell wall
What labs would you order to monitor pt on pyrazinamide?
serum uric acid for adherence monitoring
LFTs in pt’s w/ liver dz
MDR-TB caused by…
organisms resistant to at least 2 of the best anti-TB drugs: isoniazid and rifampin
Bedaquiline box warning:
increased mortality
QT prolongation >500ms
MDR-TB can take up ___ months to cure
24
What parameters would you monitor for pt on ethambutol?
baseline visual acuity testing and color discrimination; monthly if taking >15-20mg/kg, renal insufficiency, or taking longer than 2 mo’s
What are the 2nd line TB meds?
streptomycin, amikacin/kanamycin, capreomycin, p-aminosalicylic acid, moxifloxacin
What 2nd line TB drugs have ADE’s for ototoxicity and nephrotoxicity?
streptomycin
amikacin/kanamycin
capreomycin
Ethambutol ADE
Retrobulbar neuritis
Think “eye-butol”
MOA of bedaquiline
Inhibits proton transfer of ATP synthase
*Used in MDR
