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42 Cards in this Set
- Front
- Back
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What organisms are involved in Atypical Mycobacterial infections?
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MOTT - Mycobacteria Other Than Tubercle bacilli
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Why are there specific drugs for treating MOTT bacteria?
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Because MOTT are not generally sensitive to many anti-TB regimens
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What are the 2 main drugs for treating MOTT bacteria?
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-Rifabutin
-Clarithromycin |
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What is the major atypical mycobacterial infection we worry about?
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Mycobacterium avium intracellulare (MAI/MAC)
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In what patients is MAI one of the most frequent opportunistic infections?
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AIDs patients
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How do AIDS patients come in contact and acquire MAC?
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It is ubiquitous in water and the environment
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What ist he first step to take if AFB are identified? Why?
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Treat with Anti-TB drug regimen until the agent is identified - because MAC is less fatal than M. Tb
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And what are the 2 drugs for treating MOTT?
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-Rifabutin
-Clarithromycin |
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What is Rifabutin?
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A lipophilic analog of Rifampin
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What are 2 main uses of Rifabutin?
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-Single agent PREVENTION of MAC
-Multi-drug TREATMENT of MAC or other mycobacteria |
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What can Rifabutin be used for in treating M. tb?
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Treating Rifampin-resistant strains of TB
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What should you NOT do with Rifabutin for treating M. TB?
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Never give it alone - it will likely lead to selection for a Rifampin-resistant population.
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What is the main side effect of Rifabutin and how does it compare to that caused by Rifampin?
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Induction of Cyp enzymes leading to drug interactions; less potent inducer than Rifampin tho
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What is Clarithromycin?
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A macrolide antibacterial
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What is Clarithromycin used for in treating MOTT?
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Multi-drug therapy for AIDS patients with MAI
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What happens if you give Clarithromycin by itself instead of as part of multi-drug therapy?
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It loses its activity
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When used for normal bacteria, is Clarithromycin bactericidal or static?
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STATIC
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What is Clarithromycin when used for MOTT/MAC?
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Bactericidal! Even for Intracellular forms!
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So what are the 2 uses of Clarithromycin?
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-Multidrug TREATMENT of MAC
-Prophylaxis of MAC |
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What is a reason for choosing Clarithromycin over Rifabutin for treating MAC?
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Clarithromycin avoids CYP induction
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What is a downside to Clarithromycin however?
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It has its own drug interactions as Macrolides inhibit Cyp3A4
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What agent causes Leprosy?
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Mycobacterium leprae
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Who can treat leprosy?
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Only specialists!
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What are the 2 types of leprosy?
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-Lepromatous
-Tuberculoid |
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Why is it so hard to study leprosy?
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The bacillus can't be grown in vitro so susceptibility testing is not possible!
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What are the 3 drugs we have for treating Leprosy?
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-Clofazimine
-Dapsone -Rifampin |
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What is Dapsone?
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A structural analog of PABA - para aminobenzoic acid
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How does Dapsone work?
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It inhibits folic acid synthesis
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Is Dapsone bacteriocidal or static?
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STATIC
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How is Dapsone used in treating leprosy?
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In combination with other drugs
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What is a use of Dapsone completely unrelated to treating Leprosy?
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Treatment of pneumocystis jiroveci in AIDS patients
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What is the metabolism of Dapson like?
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Similar to Isoniazid; so there are slow and fast acetylators
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What are 2 major adverse effects of Dapsone?
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-Hemolytic anemia
-Methemoglobinemia |
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What determines the likelihood of patients on Dapsone getting hemolytic anemia or methemoglobinemia?
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The dose
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What is Clofazimine?
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A DYE! (Phenazine dye)
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How does Clofazimine work?
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It binds to DNA and interferes with bacterial reproduction and growth
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What is Clofazimine used for?
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Combination therapy of Leprosy that is resistant to Dapsone
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What is an adverse side effect of Clofazimine?
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Red-brown pigmentation of the skin
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What other drug can be used to treat leprosy, especially in combo with Dapsone?
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rifampin
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What requires 1 yr vs 2 yrs of treatment; tuberculoid or lepromatous leprosy?
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Lepromatous - 2 yrs
Tuberculoid - 1 yr |
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What drugs would be given daily for 2 yrs for lepromatous leprosy?
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-Dapsone
-Rifampin -Clofazimine |
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What drugs would be given daily for 1 yr for tuberculoid leprosy?
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Dapsone + Rifampin
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