Quiz 5 - TB, Leprosy, And Diarrhea Flashcards
Tell me about mycobacterium.
Aerobic, acid-fast bacilli
*Almost impermeable hydrophobic cell wall of mycolic acid and lipids
**Hard for antimicrobials to do their job
***Efflux pumps to pump harmful stuff out, and some spp. Can hide inside pts cells
What two key diseases does mycobacterium cause?
Mycobacterium tuberculosis
— 9 million new cases and 2 million deaths annually worldwide
Mycobacterium leprae - Hansen’s Disease
— >2 million new cases worldwide
T/F - Bacteria grow better in areas with cooler body temps closer to skin surface.
TRUE
Primary TB - Latent or Asymptomatic - prophylactic treatment of choice?
Isoniazid for 9 months
Primary TB - Overt/Active - Tx of choice?
“2 with 4, then 4 with 2”
2 months with Rifampin, Isoniazid, Pyrazinamide, Ethambutol
—RIPE
—**Only take Pyrazinamide for up to 2 months. It can be hepatotoxic
Follow with 4 months with Rifampin and Isoniazid
—RI
Secondary TB is at greatest risk for what populations?
HIV+
Immunosuppressed
High risk
What is the rule of 5s?
Pts with mycobacterium TB have a 5% risk in the first 2 years and a 5% lifetime risk
**Pts with HIV have a 5+5% risk of reactivation PER YEAR
What is the tx of choice for secondary TB?
“2 with 5, then 4 with 2”
2 months with combination of Rifampin, Isoniazid, Pyrazinamide, Ethambutol, and STREPTOMYCIN
-RIPES
Follow with 4 months of just Isoniazid and rifampin.
Streptomycin is what?
Azithromycin is what?
Rifampin is what?
Strep - Aminoglycoside - 30S ribosomal inhibitor
Azithromycin - Macrolide - 50S ribosomal inhibitor
Rifampin - Nucleic acid synthesis inhibitor
What drug is the choice for prophylaxis of active TB?
Isoniazid
What is Isoniazid’s mechanism?
Decrease mycolic acid synthesis
-Must be activated by the bacterial enzyme Kat G, which is a TB catalase oxidase enzyme
—This produces free radicals
What are some adverse effects of Isoniazid?
Hepatotoxicity
Can cause a pyridoxine deficiency
—ALWAYS ADMINISTER WITH VITAMIN B6 TO MAINTAIN HEME SYNTHESIS AND PREVENT NEUROTOXICITY
*Also, pts need to avoid alcohol during and before/after intake
T/F - Pyrazinamide is a prodrug.
TRUE
When is Pyrazinamide used?
ACTIVE TB infection
What is Pyrazinamide’s mechanism?
Inhibits mycolic acid synthesis
Req’s acidic pH to be activated
*It is an essential part of the tx of TB meningitis
**Crosses the BBB
