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Pharm - Tuberculosis
Tuberculosis
101
Pharmacology
Graduate
03/02/2010

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Cards

Term
What happens if TB is left untreated?
Definition
It causes progressive tissue destruction and eventually death
Term
What is the leading killer globally?
Definition
TB
Term
How many people die each minute in India from TB?
Definition
1 person
Term
How many people are infected with TB?
Definition
2 billion
Term
How many people die of TB each year?
Definition
2-3 million
Term
How many people in the US are latently infected with TB?
Definition
10-15 million
Term
What is the lifetime risk of active disease for those with latent TB?
Definition
10%
Term
Is TB reportable?
Definition
Yes, it must be reported to the local health department
Term
What causes TB?
Definition
Mycobacterium tuberculosis
Mycobacterium bovis
Term
Why do we pasteurize milk?
Definition
to prevent TB from Mycobacterium bovis
Term
Which organism is used to make the TB vaccine?
Definition
Mycobacterium bovis
Term
True/False
The number of cases of TB in foreign born persons increased 5% from 1993-2004, while the cases among US born persons fell 62%.
Definition
True
Term
Name the top 10 countries from which persons are at a higher risk for developing TB (or having latent TB infection).
Definition
Mexico, Philippines, Vietnam, India, China, Haiti, South Korea, Guatamala, Ethiopia, Peru
Term
What 5 states account for half of all TB cases in the US?
Definition
California, Florida, Illinois, New York, and Texas
Term
What % of cases of immigrants with TB have lived in the US for more than 5 years?
Definition
25%
Term
What is the transmission rate for TB with close contact?
Definition
30%
Term
What % of patients (ages 25-44) with TB also have HIV?
Definition
20%
Term
When was the tuberculin skin test first developed?
Definition
1910
Term
What is the oldest diagnostic test still in use in modern medical practice?
Definition
tuberculin skin test
Term
What does PPD stand for?
Definition
protein purified derivative
Term
Why does a PPD test come back as a false positive in someone who has had the BCG vaccine?
Definition
it contains over 200 antigens shared with the bacille Calmette-Guerin vaccine (TB vaccine)
Term
How many people have been vaccinated for TB?
Definition
3 billion
Term
What is the QuantiFERON-TB Gold Test?
Definition
a test based on whole blood ELISA that is approved for in vitro diagnostics by the FDA
Term
How do you read a TST (or PPD)?
Definition
Look and feel for induration. Mark the induration with a pen and measure

>15 mm is +
>10mm in an exposed, diabetic, or kidney disease individual is +
>5mm in an immunocompromised individual is +
Term
Why is Gram stain not helpful with TB?
Definition
It doesn't stain well with Gram's stain
Term
What does TB's resistance to Gram staining tell us about treatment?
Definition
drugs that attack the cell wall by binding peptidoglycan will not be very effective
Term
What stain is used for TB?
Definition
Ziehl-Neelsen stain (ZN); it can pick up 8,000-10,000 organisms per mL
Term
Does a negative ZN smear mean that there is no TB?
Definition
No, it may still result in a positive culture
Term
How slowly does TB grow?
Definition
It doubles every 20 hours - whereas most bacteria double every 30 minutes
Term
How sensitive is the TST (PPD)?
Definition
100%
Term
How specific is the TST (PPD)?
Definition
83.3%
Term
How sensitive is the QuantiFERON test?
Definition
87.2%
Term
How specific is the Quanti-FERON test?
Definition
98.8%
Term
Why should TB screening be offered to all immigrants and refugees as a PPD test?
Definition
a large number of post-arrival follow-ups are never completed by the CDC
reaction in those vaccinated isn't bad and it allows you to check for latent infection
treatment of latent infection is optional and you now have an opening to discuss it with your patients
Term
Who else might you consider routinely screening for TB?
Definition
any immunocompromised patient, especially those that are institutionalized (nursing home, prison, etc), and any healthcare workers
Term
What do you do if pulmonary TB is suspected?
Definition
Get 3 induced sputum samples on 3 different days
Acid Fast Bacilli smears
cultures
nucleic amplification

Get a CXR in all patients with cough or pulmonary disease
Get fluid from the extrapulmonary site of infection or fine needle biopsy of a mass
Term
T/F
T-lymphocytes destroy immature macrophages that are unable to kill bacteria.
Definition
True
Term
Where do M. tuberculosis bacteria multiply?
Definition
In the macrophage cytoplasm, because they can inhibit the fusion of lysosomes to phagosomes so they aren't killed
Term
What is lipoarainomannan (LAMM)?
Definition
a principle component of the bacterial cell wall of M. tuberculosis that can block cytokine activation of macrophages
Term
Why is hydrogen peroxide less effetive against Mycobacterium tuberculosis?
Definition
LAM scavanges superoxides
Term
How is TB infection spread?
Definition
airborne
puncture wound
ingestion
Term
How many bacteria ar cause TB infection?
Definition
1-3 bacteria
Term
What 3 factors determine the progression of TB?
Definition
1. The number of organisms inhaled
2. The virulence of the organism
3. The host's cell mediated response
Term
What happens after the bacteria enter the body?
Definition
Large numbers of macrophages surround the caseous TB foci and form granulomas to contain the organism
Term
What qualifies the latent phase of TB?
Definition
The infection is under control
Term
What % of patients with latent phase TB will become infected in their lifetime?
Definition
10%
Term
What % of those with latent TB infection that do become infected, have it happen within 2 years of exposure?
Definition
nearly 50%
Term
What % of TB patients should be screened for HIV?
Definition
100%
Term
What % of HIV patients should be screened for TB?
Definition
100%
Term
What is the most common form of extrapulmonary TB?
Definition
lymphadenitis
Term
What % of TB cases is pleural TB?
Definition
5%
Term
What other extrapulmonary sites are found with TB?
Definition
bone, joint, genitourinary, meningeal
Term
What is miliary TB?
Definition
a massive innoculation of organisms enters the blood stream causing widely disseminated progressive disease
Term
What are the 9 desired outcomes with treatment of TB?
Definition
1. Rapid ID of patient with TB
2. Isolation of patient to protect others
3. Collection of smears and cultures
4. Initiation of specific treatment
5. Resolution of s/s of disease
6. Achieve noninfectious state
7. Patient adherence to treatment
8. Cure the patient ASAP
9. ID the strain and check for resistance
Term
What are 3 nonpharmacologic measures to treat TB?
Definition
1. Prevent the spread - report it and isolate patient
2. Use contact info to ID spread of the disease - PPD testing of contacts
3. Restore the patient to normal wt and well being
Term
How many bacteria are present in an asymptomatic patient?
Definition
1000
Term
How many bacteria are present in the patient with cavitary pulmonary TB?
Definition
100 billion
Term
What is the naturally occurring resistance rate in bacteria?
Definition
1 in 1 million to 100 million
Term
Why do we use combination therapy to treat TB?
Definition
By using more drugs, we reduce the resistance rate to an almost impossible number. This is important because it only takes 1-3 bacteria to colonize the patient.
Term
How many drugs are typically included in the regimen to treat TB?
Definition
4
Term
How many drugs are approved for the treatment of TB?
Definition
10
Term
Name 4 drugs approved by the FDA to treat TB.
Definition
quinolones, amikacin, kanamycin, rifabutin
Term
What is the first phase of treatment for TB?
Definition
8 weeks of daily therapy with isoniazid, rifampin, ethambutol, and pyrazinamide
Term
What is the second phase of treatment?
Definition
18 weeks (daily, 5x/week, or 3x/week) of meds depending on the initial response
31 weeks for phase 2 if cavitation on initial CXR
Term
What are considered the first line therapies for TB?
Definition
isoniazid, rifampin, amikacin, and kanamycin, ethambutol, pyrazinamide, rifabutin
Term
What is the action of isoniazid?
Definition
prevents the synthesis of mycolic acids and mycobacterial cell walls
Term
What are possible side effects of isoniazid?
Definition
fever, skin rashes, drug induced hepatitis
Term
Why do you need to monitor AST and ALT levels in TB patients taking isoniazid?
Definition
it can cause drug-induced hepatitis
Term
What is rifampin's mechanism of action?
Definition
it inhibits RNA synthesis in bacteria
Term
What are the side effects of rifampin?
Definition
orange color to urine, sweat, tears, and contact lenses; rashes, thrombocytopenia (anemia), and nephritis
Term
What is the mechanism of action of amikacin?
Definition
binds 30S ribosomal subunits
Term
When is drug resistance a problem with TB?
Definition
when there are compliance issues
Term
What drugs used to treat TB can cause drug-induced hepatitis?
Definition
isoniazid, rifampin, pyrazinamide
Term
How many times normal do AST and ALT get before causing symptoms?
Definition
3x normal
Term
What is the maximum that AST, ALT levels can reach?
Definition
5x normal
Term
If AST, ALT levels are elevated, what do you do?
Definition
use 2 or more drugs to replace the hepatitis-causing drug until liver enzymes normalize, then resume again with monitoring

Replace with ethambutol, streptomycin, amikacin, kanamycin
Term
Before TB treatment, what lab tests should you run?
Definition
ALT, AST, bilirubin, and CBC
Term
Why should TB treatment patients be monitored monthly?
Definition
adherence to meds, s/s of peripheral neuropathy (caused by isoniazid), symptoms of hepatitis (nausea, emessis, dark urine, abdominal pain), signs of hepatitis (jaundice, hepatomegaly or tenderness).
Term
What happens if you use isoniazid with phenytoin?
Definition
you get increased levels of both drugs
Term
Which drug should you use in patients on antiretroviral therapy for HIV?
Definition
rifampin CI
Term
What TB drug should not be used in children and why?
Definition
ethambutol because of risk of diminished visual acuity
Term
What drug regimen do you use to treat children with TB?
Definition
isoniazid, rifampin, and pyrazinamide
and 4th if there is severe pulmonary disease
Term
How should you treat latent TB in pregnant women?
Definition
Don't. Wait until after delivery.
Term
When should therapy for active TB infection in pregnant women begin?
Definition
second trimester
Term
What is the 3 drug regimen used to treat active TB in pregnant women? Why are these used?
Definition
isoniazid, rifampin, and ethambutol
they are used because of their lack of teratogenic effects
Term
What is the risk of TB in pregnant women?
Definition
transmission to the fetus
Term
Can women breast feed while undergoing TB treatment?
Definition
yes, unlikely to be toxic levels; however, levels are not high enough to treat infant for TB
Term
What drug is given to pregnant and lactating patients with TB who are taking isonizid?
Definition
pyridoxine because it prevents the neuropathy induced by isoniazid
Term
When do you use pyridoine in TB treatment?
Definition
pregnant and lactating patients to prevent neuropathy induced by isoniazid and also in HIV and malnourished patients
Term
When a TB patient is in advanced liver disease, which drug(s) do you use?
Definition
rifampin
Term
What medications do you use to treat HIV patients with TB?
Definition
same drugs as with non-HIV patients, except if the patient is on antivirals, in which case - no rifampin
Term
How many people in the US have latent TB?
Definition
10-15 million
Term
What are the high risk groups for latent TB?
Definition
foreign born, close contacts of TB patients, racial and ethnic minorities, and congregate living
Term
When is the greatest risk for latent TB to become active infection?
Definition
Within 2 years of exposure
Term
What 3 drugs may increase risk of latent TB becoming active TB? How do they cause this?
Definition
infliximab, etanercept, or adalimumab

they inhibit tumor necrosis factor alpha
Term
What is the treatment for active TB?
Definition
rule out active disease
treat with isonizid, Vitamin B2 pyridoxine, rifampin, or rifabutin
Term
How must isoniazid be taken?
Definition
on an empty stomach, and no antacids for 2 hours
Term
Why is Vitamin B6 given to latent TB patients?
Definition
specifically given to pregnant, alcoholics, and malnourished because it prevents neuritis in these populations
Term
With treatment, the lifetime risk of latent TB becoming an active infection drops from 10% to what?
Definition
1%
Term
What is the treatment for resistant TB?
Definition
isoniazid, rifampin, pyrazinamide, + 2 or 3 additional agents
Term
When do most relapses of TB occur?
Definition
first 6-12 months after completion of therapy
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