Anti Mycobacterial drugs Flashcards
Isoniazid mechanism of action?
Prodrug requiring conversion by mycobacteriums own catalase. Upon conversion the drug inhibit mycolic acid synthesis.
treatment lasting from 6-9 months!
Four primary drugs to treat TB?
Isoniazid, rifampin, ethambutol and pyrazinamide
Isoniazid side effects?
Hepatitis Pheripheral neuritis(enzyme use vitamin B6) Sideroblastic anemia(due to B6 deficiency)
Rifampin mechanism of action?
inhibits transcripition of mycobacterial DNA
Ethambutol mechanism of action?
inhibits synthesis of arabinogalactan(cell wall component)
pyrazinamide mechanism of action?
unknown
isoniazid moa?
administered as prodrug - the active metabolite inhibts enoyl ACP-reductase, an enzyme that produces mycolic acid(cell wall)
isoniazid distribution?
enters most body fuids and accumulates in caseated lesions and intracellularly in host, which kills mycbacteria that recides there
INH adverse effects?
hepatotoxicity and peripheral neuropathy
INH “origin” or structure?
B6 analogue
two drugs that are coadministered with INH?
Ethanbutol and streptomycin - to prevent resistance to INH
What is the characteristics of a pos PPD skin test?
5 mm = positive in HIV patients
10 mm = positive in those who recently visited high prevalence country
15 mm = positive in those with no risk factors
Comon drug regimen for TB?
INH + rifampin + ethanbutol + pyrazinamide for 4 months
continue with INH and rifampin for 6 months
a total of 6 months. Pretty long time innit’?
Mycobacterium leprae first line treatment?
Dapsone
Dapone moa?
inhibits dihydropteroate synthase from synthesizing folic acid
