18. Metronidazole. Fidaxomicin. Rifaximin. Urinary antiseptics. Phosphomycin Flashcards
1
Q
Fidaxomicin
A
Protein synthesis inhibitor
- Inhibits RNA polymerase - disruption of transcription
- Bactericidal
- narrow , (G+) (c.difficile)
- Oral
- ——————————————————————————–GI (nausea, vomiting)
- hypersensitivity
2
Q
Rifaximin
(Rifampicin group)
A
- Interacting with DNA dependent RNA polymerase
- semisynthetic, rifamycin-based non-systemic antibiotic.
- G(+) (staphylo, strepto, enterococcus)
- G(-) (moderate action against the intestine bacteria)
- Oral administration does no absorb from the GI!!
- Hepatic encephalopathy,
- Prophylaxis before colorectal surgery,
- Acute(noninflammatory) Enteritis(drug of choice),
- Colitis
3
Q
Urinary antiseptics
A
Methenamine
Decomposes to formaldehyde in acidic pH
(toxic for bacteria)
- oral
- Chronic suppressive therapy for UTI
- GI distresses
- ——————————————————————————-Nitrofurantoin
Damages bacterial DNA- reduced to highly active intermediates
-uncomplicated lower UTI
(in pregnancy, in children, in case of resistance)
———————————————————————————GI symptoms
-hypersensitivity pulmonary reaction
4
Q
Phosphomycin
A
Cell wall synthesis inhibitor
(Inhibits the first step in formation of UDP-N-acetylmuramic acid)
- Bactericidal
- G( +) and G (-) (ESBL E.coli), E.faecalis
-oral or parenteral
(no minimal 7 days administration - maintaining concentration in the urine)
- GI symptoms
5
Q
Metronidazole
A
-free radical metabolites disrupt bacterial DNA
(form free radicals) Bactericidal
- Coverage of polymicrobial anaerobic infections (intra-abdominal infections)
- activity against Entamoeba histolytica (liver abcess)
- activity against giardia
- treats vaginitis and cervicitis caused by protozoal infection(treat both patient and partner)
- treats bacterial vaginosis caused by gardenella
- substitute for amoxicillin in the triple therapy for helicobacter pylori infection in penicillin allergic patients
- activity against anaerobic bacteria
(bacteroides, prevotta, fusobacterium, clostridium) - treats pseudomembranous colitis caused by clostridium
- Clindamycin above the diaphragm, metronidazole below