Flashcards in Miscellaneous And Urinary Antiseptics (metro and nitro) Deck (12):
First drug to discuss in this category is metronidazole. What is the MOA of this drug?
Imidazole derivative -- activity against protozoa and bacteria
--activity is dependent on anaerobic conditions as it undergoes a reductive bio-activation of its nitro group by ferredoxin.
--forms reactive cytotoxic products that interfere with nucleic acid synthesis.
What is the spectrum of activity and clinical applications of metronidazole?
Anaerobes (bacteriodes and clostridium)
--of anaerobic or mixed intra-abdominal infections, vaginitis (trichomonas, vaginosis) and brain abscesses (alot of times in combo with the other anaerobe abx clindamycin)
Metronidazole is the drug of choice for what?
Tx of C. difficile infections
In combo with other drugs, metro can be used in the eradication of what?
As an antiprotozoal drug, metro is the drug of choice in what infections?
Tx of intestinal amebiasis and amebic hepatic abscesses
What are the pharmacokinetics for metronidazole?
Oral, IV, rectally, or topically (vaginal gel)
Widely distributed and penetrates well into the CSF and brain
Metabolized in the liver and may accumulate in hepatic insufficiency
What are the adverse effects of metronidazole?
1. Prolonged use: n/d and peripheral neuropathy
2. Disulfram like effects: avoid in alcoholics
3. Opportunistic fungal infections
4. Dark coloration of the urine
What are the contraindications of metronidazole?
Pregnancy: avoided during 1st trimester
The last drug is a urinary antiseptic, Nitrofurantoin. What is the MOA?
Rapidly secreted into the urine --- acts to suppress bacteriuria
No systemic effects
Formation of reactive intermediates that damage bacterial DNA
No cross-resistance with other drugs and the emergency of resistance to nitro is very slow
What is the spectrum of activity and clinical applications?
Bacteriostatic and Bactericidal
Gram + and Gram -
P. aeruginosa and Proteus = resistant
prophylaxis and treatment of lower UTIs
(nitro is a good alternative oral agent for the tx of UTIs)
What are the pharmacokinetics for nitro?
Metabolized and excreted rapidly -- so no systemic antibacterial action