2/14/17 SMITH antibiotics 5 TEST #2 Flashcards
What type of bacterium have nearly impermeable cell walls?
-Mycobacterium
What shields and prevents many drugs from accessing the cell membrane of mycobacterium?
-Mycolic acids
What are three way that mycobacterial defenses make it exceptionally difficult for antimicrobials to do their jobs?
- Thick hydrophobic cell wall
- Efflux pumps
- Some species can hide inside patients cells
What area of the body does Mycobacterium tuberculosis primarily effect?
-Lung, but can cause disease in almost any tissue
What conditions do Mycobacterium leprae grow better in?
-Cooler body temps closer to skin surface
What are other names for a TB test?
- TST
- PPD
If a person has a TST greater than 5 mm who is that indicative of a positive TB test in?
- HIV patients
- Close contacts of active cases
- Have fibrotic chest x-ray films
What is the prophylactic treatment of choice for some who has latent/asymptomatic infections of primary tuberculosis?
-Isoniazid for 9 months
What is the treatment of choice for over/active infection of primary tuberculosis?
-(RIPE) Rifampin + Isoniazid + Pyrazinamide
+ Ethambutol
When you are treating the overt/active infection of Primary TB after you do a 2 month treatment with what do you do?
-Do a 4 month treatment of Rifampin + Isoniazid
If there is an intracellulare organism in the overt/active infection of primary TB how do you treat?
-RIPE for 12 months + azithromycin
How long is the longest you should use the Pyrazinamide in a TB treatment?
-2 months because of hepatotoxicicity
Healthy patients infected with TB have a ____ % risk of reactivation in the first ____ years and then a ____ % lifetime risk of reactivation?
- 5
- 2
- 5
What is the treatment of choice for secondary TB?
- (RIPES)
- Rifampin + isoniazid + pyrazinamide +Ethambutol + streptomycin (2 months)
- 4 months treatment with isoniazid and rifampin
What is an aminoglycoside drug that can be used in TB?
-Streptomycin
What is a macrolide drug that can be used in TB?
-Azithromycin
What is a nucleic acid synthesis inhibitor drug that can be used in TB?
-Rifampin
What is the Drug of choice for a prophylaxis treatment of Mycobacterium tubercuosis?
-Isoniazid (INH)
What is the mechanism of Isoniazid?
-Decreases Mycolic acid synthesis
T/F Isoniazid is a prodrug
True
Where is Isoniazid activated?
-Bacterial enzyme KatG
Whenever you give a patient Isoniazid what do you always want to administer with it?
-Vitamin B6
What is the purpose of administering vitamin B6 with Isoniazid?
- Maintain heme synthesis
- Prevent neurotoxicity
What are the adverse effects of Isoniazid?
- Hepatotoxicity
- Disulfuram-Like reaction (Hangover feeling)
What drug do you use in the treatment of Active Mycobacterium tuberculosis infection?
-Pyrazinamide
What is the mechanism of Pyrazinamide?
-Inhibits mycolic acid cynthesis
What are the adverse effects of Pyrazinamide?
- Hepatotoxicity
- Can cause gout or make it worse
- Contraindicated in pregnancy
What does Pyrazinamide require to be activated?
-Acidic pH
When is Ethambutal used?
-Treatment of active mycobacterium tuberculosis
What is the mechanism of action for Ethambutal?
-Decrease carbohydrate polymerization by inhibiting arbinosal transferase
What are the major adverse effects of ethambutal?
- Ocular toxicity
- Ocular neuritis (lead to blindness)
What drug do you use for multi-drug resistant TB?
-Bedaquiline
What is the mechanism of Bedaquiline?
-Inhibit mycobacterial ATP synthase
What is the adverse effect of Bedaquiline?
-Prolonged QT syndrome
What are four drugs that cause hepatotoxicity?
- Rifampin
- Isoniazid
- Pyrazinamide
- Dapsone
What is the drug of choice for treatment for TB and Leprosy?
-Rifampin
What is the drug of choice for prophylaxis of Leprosy?
-Dapsone
What is the mechanism of Dapsone?
-Competes with PABA to inhibit bacterial dihydrofolate synthesis
What two diseases do you use Dapsone in for prophylactic treatment?
- Leprosy
- Pneumocystis jiroveci
Which type of leprosy has a poor immune response?
-Lepromatous leprosy
What type of leprosy has a good immune response?
-Tuberculoid leprosy
What is the drug of choice for the treatment of traveler’s diarrhea due to E. coli?
-Rifaximin
What is the drug of choice when you have invasive Campylobacter and Shigella causing traveler’s diarrhea?
-Ciprofloxacin (flouroquinolone)
If you have Pseudomembranous colitis (C. difficile) causing diarrhea what is the drug of choice?
-Metronidazole
