Treatment for TB Flashcards
First-line agents for TB
Rifampin
Isoniazid
Pyrazinamide
Ethambutol
Mechanism of rifampin
Binds to beta subunit of bacterial DNA dependent RNA polymerase to inhibit RNA synthesis
Bacterial resistance to rifampin
Point mutation in beta subunit gene
Decreased binding
Contraindications of rifampin
Strong CYP450 inducer
Drug for TB that turns urine, sweat, and tears orange
Rifampin
Adverse effects of rifampin
Cholestatic jaundice
Hepatitis
Light-chain proteinuria
Flu-like syndrome
Acute tubular necrosis
Drug that inhibits synthesis of mycolic acids after activation by bacterial catalase peroxidase
Isoniazid
Bacterial resistance to isoniazid
Decreased KatG
Drug for TB that is metabolized by liver N-acetyltransferase and thus affected by rapid vs slow acetylators
Isoniazid
Adverse reactions of isoniazid
Hepatitis
Drug induced SLE
Peripheral neuropathy
Sideroblastic anemia
Reason for peripheral neuropathy adverse effect of isoniazid
Relative pyridoxine deficiency
How is pyrazinamide converted to pyrazinoic acid, its active form?
Mycobacterial pyrazinamidase
Mechanism of pyrazinamide
Disrupts mycobacterial cell membrane metabolism and transport functions
Bacterial resistance to pyrazinamide
Impaired uptake
Mutations in pyrazinamidase
Adverse effects of pyrazinamide
Hepatoxicity
Hyperuricemia
Drug that inhibits mycobacterial arabinosyl transferases and polymerization reaction of arabinoglycan
Ethambutol
Bacterial resistance to ethambutol
Mutations resulting in overexpression of arabinosyl transferase gene
Adverse reactions of ethambutol
Retrobulbar neuritis
TB drug that can cause loss of visual acuity and red-green color blindness
Ethambutol
Intensive phase of treatment for active TB infection
2 months of RIPE
Continuation phase of treatment for active TB infection
Rifampin and isoniazid for 4 months
Adjuvant treatment for active TB infection
Pyridoxine
Treatment for latent TB infection
Isoniazid for 9 months
Second-line drug for TB mainly active against EC tubercle bacilli
Streptomycin
Site of action of streptomycin
30S subunit of ribosome
Adverse effects of streptomycin
Ototoxic - vertigo and hearing loss
Nephrotoxic
Adverse effects of capreomycin
Nephrotoxic
Ototoxic - tinnitus, deafness, vestibular disturbance
Structural analog of D-alanine that inhibits wall synthesis. Used as a second-line treatment for TB.
Cycloserine
Adverse effects of cycloserine
Peripheral neuropathy
CNS dysfunction
Adverse effects of ethionamide
Hepatotoxicity
Neurologic symptoms
Drug given to reduce/alleviate the neurologic side effects of cycloserine and ethionamide
Pyridoxine
Mechanism of ethionamide
Blocks synthesis of mycolic acids
Folate synthesis antagonist structurally similar to PABA and used as a second-line treatment for TB
Aminosalicylic acid (PAS)
Bacterial RNA polymerase inhibitor often used in place of rifampin for treatment of TB in pts with HIV on antiretrovirals
Rifabutin
Rifamycin that is a less potent CYP450 inducer
Rifabutine
Effective short course treatment of latent TB when combined with isoniazid
Rifapentine
Second-line drug for TB that inhibits ATP synthesis in mycobacteria
Bedaquiline
Adverse effect of bedaquiline
QTc prolongation
Second-line drug for TB that acts as a respiratory poison following NO release
Pretomanid
