Lecture 36.1: Tuberculosis [Kays]

Question 1

What is the Etiology of Tuberculosis?

Answer 1

• Acid Fast Bacteria [AFB]: dye that isnt washed any from acid
• SLOW GROWTH; takes about 24h to double

Question 2

What is the difference between Multi-drug Resistant TB and Extensively Drug Resistant TB?

Answer 2

• MDR-TB: Resistant to INH and Rifampin
• XDR-TB: Resistance to INH and Rifampin + Resistance to FQs and Resistance to Amikacin

Question 3

What is the Pathogenesis fo Tubculosis?

Latant vs Active?

Answer 3

• It is Cell-Mediated [based on Macrophages and T-Cells]
• Latent: NO x-rays, NO symptoms, (-) studies
• Active: x-rays, symptoms, (+) studies

Question 4

What is important to know about the Primary Infection of Tuberculosis?

Answer 4

• Marcophages eat the TB but doesnt kill it
• 14-21d later; it gets into the bloodstream
• Granuloma helps wall off the infection

Question 5

What are some of the signs and symptoms of tuberculosis?

Answer 5

• Fever/Chills
• Night Sweats
• Unexplained Weight Loss
• Cough with Sputum

Question 6

What is important to know about tuberculin skin tests?

Answer 6

• PPD: proteins from TB that is an intradermal injection
• Measures the Induraiton; size of the Diamemeter might indicate TB

Question 7

What is one thing that should be tested for before giving a patient Rifampin?

Answer 7

• Mutation in rpoB gene

Question 8

What are the treatment goals of tuberculosis?

Answer 8

• Get negtive sputum
• Prevent emergence

combo drugs can help with this

Question 8

What is the PreferRed Intensive and Continuation Phase for the Treatment for Tuberculosis?

Answer 8

• Intensive: Rifampin, INH, Pyrazinamide, Ethambutol for 7 days/week
• Continuation: Rifampin and INH

Question 9

What are some of the important notes about the other Tuberculosis regimens?

Answer 9

• Caution with patients with HIV and Cavitary Disease; a missed dose can cause failure
• DO NOT use twice weekly regimens with HIV

Question 10

What is important to give when giving INH?

Answer 10

• Pyridoxine or Vit B6 should be given

Question 11

What is the treatment for Latent Tuberculosis?

Answer 11

• Rifampin 600 mg x 4m [Preferred]
• INH 900 mg + Rifapentine 900 mg once weekly [Preferred]
• INH + Rifampin x 3m [Preferred]
• INH 300 mg qd x 9m [alt]

Question 11

What are some of the tuberculosis treatments within speacil populations?

Extrapulmonary TB? TB Meningitits? Children? TB pregnancy?

Answer 11

• Extraplumonary TB: Same Regimen –> 9 months
• TB Meningitis: Same Regimen –> 9 - 12 months
• Children: Same Regimen [Ethambutol NOT for < 6y]
• TB Pregnancy: Rifampin, INH, Ethambutol for 9 months

Question 12

What is the Pharmacology of Isoinaid?

Answer 12

• Metabolized in Liver [genetics shows rapid or slow
• Severe Hepatic issues = Reduce dose by 1/2
• Renal failure

Question 13

What are some of the Adverse Effects of Isoniazid?

Answer 13

• Hepatitis
• Neurotoxicity [increased pyridoxine excretion (B6) = AWLAYS give B6 with INH

Inhibitor of P450

Question 14

What are some of the adverse effects of Pyrazinamide?

Answer 14

• Hepatoxicitiy
• Hyperuricemia [Pyarazinoc acid competes with Uric acid for elimination]

Question 15

What are some of the adverse effects of Rifampin?

Answer 15

• Hepatoxicity [increased bilirubin
• Discolored body fluids [Sweat, Tears, Urine are like ORANGE]
• VERY potent inducer of P450

Question 16

What is the Pharmacology of Ethambutol?

Answer 16

• Primarily renally eliminated unchanged (80%) = ADJUST

Question 17

What are some of the Adverse Effects of Ethambutol?

Answer 17

• Peripheral Neuropathy
• Optic Neuritis