C2 Flashcards
Antimycobacterial drugs؟
1st line : Rifampin Isonazide Pyrazine.amide Ethambutol
2nd line :
Streptomycin
Cycloserine
Kanamycin
leprosy drugs :
Dapson
clofazimine
rifampin
Drugs for Tuberculosis?
RIPES
What is the MOA of antituberculotix?
what does it depends on?
- Bactericidal or Bacteriostatic
- depending on drug concentration and strain susceptibility
Isoniazid MOA?
is it effective for dormant or growing bacilli?
- Inhibits the synthesis of mycolic acids (cell walls)
- it is bactericidal for actively growing tubercle bacilli, but is less effective against dormants
Isonazid PharmacoKinetix?
- absorption: well absorbed orally
- metabolism: Liver (acetylation)
- 1/2 life:
*slow acetylators 3–4 h
*fast acetylators 60–90m
(for equivalent therapeutic effects fast acetylators require higher dosage)
inhibits CYP450
Isonazide clinical uses?
- most important drug used in tuberculosis - component of most drug combination regimens
- treats of latent infection
- Prophylaxis
Isonazide Toxicity?
- peripheral neuritis
- insomnia
- muscle twitching
- inhibit the hepatic metabolism of drugs (eg, carbamazepine, phenytoin, warfarin)
- Lupus-like syndrome
Rifampin MOA?
- bactericidal
- inhibits DNA-dependent RNApolymerase
- if the drug is used alone, Resistance develops rapidly (changes in drug sensitivity of the polymerase)
Rifampin PharmacoKinetix?
- absorption: well absorbed orally
- distribution: most body tissues (even CNS)
- metabolism: partially metabolized in the liver (enterohepatic cycling)
- Elimination:خرا feces (free drug and metabolites)
inducer of CYP450
Rifampin clinical uses?
- always in combination with others
- solo: latent tuberculosis
- in INH-intolerant patients or prophylaxis for INH-resistant strains
- with dapson: leprosy
(given monthly –> delays the emergence of resistance to dapsone) - with vancomycin: against MRSA or PRSP
- meningococcal and staphylococcal carrier states
Rifampin Toxicity?
- colors sweat, urine and tears orange
- Rashes
- thrombocytopenia
- proteinuria
- nephritis
- liver dysfunction
- induces liver drug-metabolizing enzymes
- -> enhances the elimination rate of many drugs (anticonvulsants, contraceptive steroids, cyclosporine, ketoconazole, methadone, terbinafine, and warfarin)
Ethambutol MOA?
- inhibits arabinogalactan synthesis
(cell walls) - if used alone, resistance develops rapidly
Etham butol PharmacoKinetix?
- absorption: well absorbed orally
- distribution: to most tissues (also CNS)
- elimination: unchanged in the urine
In renal impairment dose reduction is necessary
Ethambutol Clinical use?
- tuberculosis
- always given in combination with other drugs
Ethambutol Toxicity?
- visual disturbances
- headache, confusion, peripheral neuritis.
- hyperuricemia