Flashcards in tb intro Deck (15):
1st line agents for TB
Rifampin (RimactaneR, Rifadin)
risk for reactivation of latent tb w. these agents??
anti-TNF agents, i.e. infliximab
tb tx requires ??
-two or more drugs to which the tubercle organisms are susceptible
-must continue 3-6 mos after the sputum becomes negative to sterilize the lesions and prevent relapse
Tubercle bacilli are killed by antituberculosis drugs only during ??
Several populations of tubercle bacilli are hypothesized to exist in the host:
-cavitary lesions: O2 tension is high, medium is neutral or slightly alkaline and multiplication active;
- in closed caseous lesions: O2 tension is low, medium is neutral and replication is slow and intermittent
-w.in macrophages: intracellular miliew is acidic and multiplication is relatively slow.
actively multiplying: alveoli
acid pH: macrophages
neutral pH: only INH, rifampin work
resistance to INH is ?? in the US
Active Disease Treatment
*Isoniazid* should be used (in conjunction with other drugs) for the duration of therapy because of its efficacy, low cost, and tolerability.
-If rifampin is not used, 18 months is the minimal duration of therapy associated with acceptable rates of cure.
-the absence of drug resistance, a regimen of isoniazid and rifampin administered for 9 months is curative.
addition of ?? for the first 2 months of treatment allows the regimen to be shortened to 6 months and is associated with improved compliance and cure rates.
6 and 9-month:
-initial phase with isoniazid, rifampin, pyrazinamide and ethambutol administered daily for 2 months,
-followed by a continuation phase consisting of isoniazid and rifampin given daily, twice a week, or three times a week for 4 months
(4 for 2, 2 for 4)
Direct observation of therapy (DOT)
encourage patients to complete therapy w. incentives
A ?? should be obtained at the beginning of treatment to help establish the diagnosis
-should also be obtained at the end of treatment as a base line for future reference.
For culture-negative cases of tuberculosis, the response to therapy is monitored by ?? at three months.
reviewing symptoms and obtaining a chest radiograph
To prevent infection in an individual with a negative Mantoux skin test in the absence of anergy who has had intimate contact with an active case.??
2 months of daily treatment with rifampin and pyrazinamide is an effective alternative treatment to isoniazid.