Midterm Exam Study Guide
Treatment protocol for tuberculosis
First 8 weeks - Rifampin, idionazid, pyrazinamide, ethambutal.
Then, isionazid and rifampin for 18 weeks.
why must TB pts take so many meds....
-Drug combination decreases the incidence of reemergence of TB 2/2 dormant TB becomes active.
-use of multiple drugs decrease emergeance of drug resistant bacilli
-Some drugs are effective against actively dividing bacilli, and other drugs are active against quiescent
bacilli.
Primary goals of TB treatment
-Eliminate infection.
-Precent relapse.
-Prevent the development of drug resistance.
- reduce transmission
- kill actively dividing and dormant bacilli.
Second line drugs for TB
aminoglycosides, fluoroquinolones, para-aminoslicyclic acid (PAS), capremycin, amikacin
Isoniazid MOA
inhibits mycolic acid synthesis, which a part of the mycobacterial cell wall.
Isoniazid indications
active and latent TB
Isioniazid drug interactions
Inhibits P450, so metabolism of some drugs will be slowed. Phenytoin , diazepam, theophylline,
warfarin.
Isoniazid adverse effects
hepatotoxicity, peripheral neuropathy, multipolar necrosis
Ethambutol MOA
decrease carbohydrate polymerization of mycobacterium cell wall by blocking arabinosyltransferase. So,
impairs mycobacterial cell wall synthesis.
Ethambutol adverse effects
, optic neuritis, GI upset, inhibits renal excretion of uric acid.
Ethambutol indications
M. tuberculosis. Even those strains that are resistant to isoniazid and rifampin.
Pyrazinamide indications
Part of multi-drug regimen for TB, especially latent.
Pyrazinamide adverse effects
Most hepatotoxic of all the first line drugs.
Rifampin MOA
Inhibits DNA-dependent RNA polymerase (transcription.) consequently, it suppresses protein synthesis.
Highly selective to TB bacterium.
Rifampin indications
TB. Lipid soluble so it can attack intracellular or quiescent bacilli.
Rifampin adverse effects
hepatitis, discoloration of urine, stools, and other body fluids to red/orange color. GI side effects,
cutaneous reactions.
Rifabutin (Mycobutin) indications
Treats TB in patients with HIV. Does not interact with antivirals.
Rifabutin adverse effects
skin rash, body fluids discoloration, neutropenia, GI upset
Aminoglycosides for TB
2nd line drug. Needs heroic. Damage to 8th cranial nerve.
Extensive Drug Resistant TB (XDR-TB)
resistant to all 1st line oral drugs + at least one 2nd line given by IV. Treatment is prolonged to at least
24 months with 2nd and 3d line drugs that are highly toxic and less effective. Therapy may consist of up
to 7 drugs. 40-60% rate of death.
Antiulcer agents
used in the treatment and prophylaxis of peptic ulcer and gastric hypersecretory conditions, e.g.,
Zollinger-Ellison syndrome. Include meds such as antibiotics that treat h. Pylori, antisecretory meds such
as proton pump inhibitors, histamine 2 receptor antagonists; mucosal protectants such as sucralfate,
and antacids.
Proton Pump Inhibitors (PPIs)