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33 Cards in this Set
- Front
- Back
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major drugs used in TB
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isoniazid, rifampin, ethambutol, pyrazinamide, streptomycin
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neurotoxic effects of this drug (peripheral neuritis, restlessness, twitching, insomnia) can be alleviated by pyridoxine
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INH
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MOA of INH?
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inhibits mycolic acid (inhibits acyl carrier protein reductase), bactericidal for actively growing bacilli
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toxic effects of INH?
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neurotoxic, hepatotoxic (abnml LFTs, jaundice, hepatitis), P450 inhibitor, induces hemolysis in G6PD def pts, lupus-like syndrome.
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metabolism of INH?
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hepatic acetylation
("fast" and "slow" acetylators) |
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what confers resistance to INH?
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deletion of katG (catalase-peroxidase that activates INH)
deletions in inhA that encodes target acyl carrier protein reductase |
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inhibits bacterial DNA-dependent RNA polymerase
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rifampin
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DOC for latent TB in INH-intolerant pts?
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rifampin
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DOC for meningococcal or staphylococcal carrier states?
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rifampin
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side effect if rifampin is given less than twice/week
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flulike syndrome and anemia
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toxic effects of rifampin?
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light chain proteinuria, impaired antibody responses, rash, thrombocytopenia, nephritis, liver dysfxn, induces P450, red/orange body fluids
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tx for TB or other mycobacterial infxn in AIDS pts d/t less drug interactions?
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rifabutin
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MOA of ethambutol
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inhibits arabinosyl transferases involved in arabinogalactan synthesis for mycobacterial cell wall
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d/t large unmetabolized fraction excreted in urine, this drug requires dose reduction in renal flr
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ethambutol
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toxic effects of ethambutol?
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vision: dec acuity, red-green blindness, optic neuritis, retinal damage
HA, confusion, hyperuricemia, peripheral neuritis |
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what confers resistance to EMB?
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mutation in emb gene when used alone
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resistance to PZA?
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mutations in bioactivating enzyme and expression of drug efflux systems
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toxic effects of PZA?
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nongouty polyarthralgia, myalgia, GI upset, rash, liver dysfxn, porphyria, photosensitivity, teratogenic
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used primarily for life-treatening tuberculous disease, i.e. memingitis, miliary dissemination, severe organ TB
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streptomycin
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drug used in streptomycin-resistant or MDR TB, but must be used in combo to avoid resistance
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amikacin
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fluoroquinolones that can be jused in conjunction with other drugs for tx of M. tuberculosis
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ciprofloxacin, ofloxacin
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similar to INH but causes severe GI irritation and neurologic effects
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Ethionamide
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not often used d/t resistance, GI upset, peptic ulceration, hypersensitivity, and effects on kidney, liver and thyroid fxn
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P-aminosalicylic acid
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not often used d/t ototoxicity and renal dysfxn
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capreomycin
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not often used d/t peripheral neuropathy and CNS dysfxn
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cycloserine
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standard regimens for pulmonary Tb in areas w/o resistance?
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3-drug (INH + RIF + PZA)
if fully susceptible, continue 4 mo w/ INH + RIF |
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alternative regimen for fully susceptible pulmonary TB?
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INH + RIF for 9 mo
or INH + EMB for 18 mo |
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what changes must be made to standard regimens if organism is resistant?
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INH resistant: initial regimen should include EMB or streptomycin
MDR: 3+ drugs that it is susceptible to for >18 mo, including 12 mo after negative culture |
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DOC for leprosy?
what else is it used for? |
dapsone
alternative tx for P. jiroveci pneumonia in AIDS pts |
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toxic effects of dapsone?
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GI upset, fever, rash, methemoglobinemia, hemolysis (G6PD def)
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drug used for M. leprae that causes red-brown to black skin discoloration
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clofazimine
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Rx for M. avium infxn?
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Azithromycin/clarithromycin + EMB + RIF
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Px against M. avium for AIDS pts w/ CD4+ < 50/uL?
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clarithromycin/azithromycin +/- RIF
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