Antimicrobials: Antimycobacterials Flashcards
What combination is used to prevent the development of resistant strains of Mycobacterium tuberculosis
combination of rifampin, isoniazid, pyrazinamide, and ethambutol used to prevent development of resistant strains of Mycobacterium tuberculosis
What is the mnemonic for the combination of drugs used to prevent the development of resistant strains of Mycobacterium tuberculosis
RIPE (rifampin, isoniazid, pyrazinamide, and ethambutol)
What are the 2 phases of treatment for tuberculosis
4 drug combination (rifampin, isoniazid, pyrazinamide, and ethambutol) for 2 months followed by 2 drugs (iosinazid and rifampin) for 4 months
Primary TB often presents as
middle lobe cavity
______ can be used alone for latent TB therapy
Isoniazid
mycolic acids are
essential components of the mycobacterial cell wall
How does Isoniazid work
INH acts on the mycobacterial cell wall by inhibiting mycolic acid production
How is isoniazid activated
INH is activated by a catalase-peroxidase (KatG)
mycobacteria develop resistance to isoniazid by
mycobacteria develop resistance to INH by downregulating Kat G
isoniazid side effects include
- peripheral neuropathy
- seizures
- hepatotoxicity
- asymptomatic rise in aminotransferases
- Drug induced lupus
- Anion gap metabolic acidosis
How is isoniazid metabolized
INH metabolized by the liver enzyme N-acetyltransferase (slow acetylators have higher risk of side effects)
How does isoniazid cause peripheral neuropathy
INH promotes excretion pyridoxine (vitamin B6) –> peripheral neuropathy
How is peripheral neuropathy from isoniazied prevented
coadministration of INH and pyridoxine prevents peripheral neuropathy
What side effect is associated with all “RIPE” therapy drugs
hepatotoxicity
Isoniazid inhibits
cytochrome P450
Rifampain activates
cytochrome P450
Which RIPE therapy drug activates cytochrome P450
Rifampin