L6: Drugs for Tb and Leprosy Flashcards
Which drug can be used to treat both Tb and Leprosy?
A. Pyrazinamide
B. Izoniazid
C. Rifampin
C. Rifampin
True or False: Tb is caused by mycobacterium tuberculosis, a bacillus
True
How is Tb acquired?
A. Oral
B. Excretory
C. Inhalation
C. Inhalation
Immunosuppression that following infection with ___ is an important risk factor for developing mycobacterial disease
HIV
Infection with tubercle bacillus results in acquired immunity and tuberculin hypersensitivity. What cell type mediates both reactions?
T-Lymphocytes
What is the first organ involved in Tb?
Lung
- Infection usually resides in the lower respiratory tract
Tubercle bacilli lodge in the ___ and may multiple in phagocytes
alveoli
True or False: Bacilli can disseminate from original pulmonary site largely through lymphatic system, to blood stream, causing infection to other organs and tissues
True
Where does Tb reactivation most commonly occur?
Upper lobes of lung
Which mycobacterial species is most frequently isolated from AIDS patients?
Mycobacterium avium complex
True or False: Therapy for treating Tb must consist of only one drug and must continue for two months
False
- drugs: should consist of two or more
- treatment: three to six months
Which three locations are tubercle bacilli believed to be found within the host?
1) Cavitary lesions
-O2 tension is high
- active replication
2) Closed caseous lesions
- O2 tension is low
- slow replication
3) Within macrophages
- acidic
- slow replication
Which two drugs function at neutral pH (extracellular)?
A. Isoniazid, Rifampin
B. Ethambutol and Pyrazinamide
A. Isoniazid, Rifampin
True or False: Rifampin, Isoniazid, Pyrazinamide, and Ethambutol all have metabolic activity in the alveoli and at acidic pH
True
What three drugs can be used to treat Tb prophylactically?
Rifampin, Isoniazid, and Pyrazinamide
In absence of drug resistance, a region of ___ and ___ administered for 9 months is curative (for Tb)
Rifampin and Isoniazid
True or False: 6 months regimens are most common for Tb treatment in the US
True
Which four drugs are used daily, for 2 months, to treat initial phase of Tb?
Rifampin, Isoniazid, Pyrazinamide, Ethambutol
Which two drugs are administered for four months to treat continuation phase of Tb?
Rifampin and Isoniazid
True or False: DOT (direct observation of therapy) has been shown to improve leprosy treatment
False - Tb tx
Which drug is the primary drug of Tb (first line anti-Tb agent, with Rifampin) but should NEVER be used alone (resistance develops!)
A. Rifampin
B. Isoniazid
C. Pyrazinamide
D. Ethambutol
B. Isoniazid
Which drug is associated with hepatitis, elevated hepatic enzymes, and peripheral neuropathy? Tx?
A. Isoniazid
B. Rifampin
C. Pyrazinomide
A. Isoniazid
- Tx: Vit B6 (pyroxidine)
True or False: Chemo for Tb in HIV patients should be given for 6 mths. Further, Isoniazid, Rifampin, and Pyrazinamide should be given daily for 2 mths.
True
Visual acuity should be measured in patients receiving:
A. Rifampin
B. Isoniazid
C. Pyrazinamide
D. Ethambutol
D. Ethambutol
If Pyrazinamide is given, baseline levels of serum ____ should be determined
Uric acid
True or False: Rash, fever, and tachy are the most common hypersensitivity reactions associated with Tb drugs
True
Mycobacterium leprae can cause ___
leprosy
Leprosy is spread by ___ from the upper respiratory tract of infection persons that enter through respiratory tract of susceptible persons
bacilli
What are the three types of Leprosy?
1) Tuberculoid: few skin lesions
2) Borderline: intermediate
3) Lepromatous: wide-spread, symmetrical distribution of skin lesions; macrophages
Which of following types of Leprosy is associated with a high CMI? low CMI?
High CMI = Tuberculoid
Low CMI = Lepromatous
Three cardinal signs of infection with M. leprae?
Skin lesions
Skin anesthesia
Enlarged nerves
Which of the following drugs primarily used Tb (but also can be used for Leprosy) suppresses RNA synthesis by inhibition bacterial DNA-dependent RNA Polymerase?
A. Rifampin
B. Isoniazid
C. Ethambutol
D. Pyrazinamide
A. Rifampin
A patient begins having GI disturbances and excretions that are red following treatment of leprosy. Which drug did she likely take?
A. Rifampin
B. Isoniazid
C. Ethambutol
D. Pyrazinamide
A. Rifampin
Which of the following drugs inhibits mycolic acid biosynthesis?
A. Rifampin
B. Isoniazid
C. Ethambutol
D. Pyrazinamide
B. Isoniazid
- Therefore: affects lipids, nucleic acids, and glycolysis
___ and ____ are first line anti-Tb agents used with Isoniazid
Pyrazimide and Ethambutol
A patient with Tb begins taking medication for treatment. However, she notices that she begins having difficulty with her vision and develops a rash. Which drug did she likely take?
Ethambutol
Which of the following is NOT a primary drug for Tb?
A. Rifampin
B. Isoniazid
C. Ethambutol
D. Pyrazinamide
D. Pyrazinamide
Which drug inhibits incorporation of mycolic acid to mycobacterial cell wall?
Ethambutol and Isoniazid
___ is only effective against Mycobacteria, while ___ is specific for Mycobacterium tuberculosis
Ethambutol; Pyrazinamide
Hyperuricemia and hepatotoxicity may be seen with use of ____
Pyrazinamide
Pyrazinamide is converted to pyrazinoic acid by mycobacteria. POA lowers __, preventing growth
pH
Human populations show genetic heterogeneity with regard to rate of acetylation of ____
A. Rifampin
B. Isoniazid
C. Ethambutol
D. Pyrazinamide
B. Isoniazid
True or False: Hepatitis is more likely to occur in a slow acetylator taking Isoniazid
True
When is Rifampin most active?
During cell replication
Which drug is used orally with isoniazid and rifampin in Tb chemotherapy?
Ethambutol
Pyrazinamide exhibits bacterial action only at a slightly __ pH
acidic
Pyrazinamide is not iteslf active, but it is hydrolyzed to the active compound _____, which has anti-Tb activity
pyrazinoic acid
Hepatotoxicity is the main serious side effect when using ___
pyrazinamide
Non-gouty polyarthralgia and hyperuricemia are AE seen with the use of which drug?
Pyrazinamide
Hepatitis (less likely than with INH) and GI disturbances are common AE associated with ____use
Rifampin
Which drug induces P450 enzymes (and therefore, may be prone to DDI)?
Rifampin
Which red color compounds treats LEPROMATOUS LEPROSY by binding to mycobacterial DNA and interfering with bacterial growth?
Hint: drug can cause skin discoloration
Clofazimine
____ is a drug that is principally bacteriostatic (not bactericidal to M. leprae) and is used for all patients infected with sulfone-sensitive Mycobacterium leprae.
Hint: it inhibits synthesis of folic acid
Dapsone
True or False: You should never use Clofazimine alone, because resistance may develop
False - does not
What are the three primary toxicities associated with Dapsone use?
1) Hemolytic Anemia
2) Methemogloinemia
3) Sulfone Syndrome
