Antimycobacterials Flashcards
first line drug for treatment of TB
RIPE Rifamycins (Rifampin and Rifabutin) Isoniazid Pyrazinamide Ethambutol
second line drug for treatment of TB
SALE Streptomycin Amikacin Levofloxacin Ethionamide
used for treatment of C. difficile
Fidoxomicin
Metronidazole
Vancomycin
drug regimen for latent TB and duration one should take the drug
Isoniazid for 6-9 months
Rifampin for 4 months
mechanism of isoniazid
is a pyridoxine (vit B6) analogue that targets mycolic acid synthesis enzymes, enoyl acyl carrier protein reductase (AcpM) and b-ketoacyl-ACP synthase
what activates isoniazid
mycobacterial catalase peroxidase
pharmacokinetics of isoniazid
one can be a fast acetylator or a slow acetylator of the drug and fast acetylators required higher doses
adverse effects of isoniazid
Lupus like syndrome
CYP450 inhibitor
Hepatotoxicity
can isoniazid be used in pregnancy
yeah but must supplement with pyridoxine aka vit b6
what are the rifamycins
rifampin and rifabutin
mechanism of rifamycins (name them)
rifampin and rifabutin
binds to beta subunit of bacterial DNA dependent RNA polymerase hence blocking transcription –> inhibition of RNA synthesis
preferred drug for treatment of TB in HIV positive patients
Rifabutin
adverse effects of rifamycins (name them)
rifampin and rifabutin
CYP450 inducer
Orange colored secretions
GI distress
mechanism of ethambutol
inhibits arabinosyl transferase involved in mycobacterial cell wall synthesis
adverse effects of ethambutol
dose dependent visual disturbances
red green color blindness
contraindications of ethambutol
children that are too young for vision tests
mechanism of pyrazinamide
conversion of the drug to pyrazinoic acid lowering the pH of environment
adverse effects of pyrazinamide
HAN
Hyperuricemia
Acute gouty arthritis
Non gouty polyarthralgia
mechanism of ethionamide
congener of isoniazid
drugs used to treat leprosy
Dapsone
Clofazimine
Rifampin
mechanism of dapsone
dihydropteroate synthesis inhibition –> inhibition of folate synthesis
structurally similar to sulfonamides
what is acedapsone
repository form of dapsone that provides inhibitory plasma concentration for several months
adverse effects of dapsone
Erythema nodosum leprosum
Hemolysis esp in G6PD
CYP inhibitor
mechanism of clofazimine
phenazine dye that bind to DNA to inhibit replication
also has redox properties that generate cytotoxic oxygen radicals
