Urinary Antiseptics Flashcards
What types of polymyxins are there?
Colistin (also known as polymyxin E) and polymyxin B
Which polymyxin is a prodrug and which is active drug?
Polymyxin B is administered directly as an active antibiotic, whereas colistin is administered as an inactive prodrug, colistin methanesulfonate (also known as colistimethate [CMS])
Mechanism of action of polymyxin?
Disrupt the cell membrane of the bacterial cell.
Spectrum of activity of polymyxins?
Gram negative
How is polymyxins administered?
Parenteral
Which of polymyxins is preferred?
Polymyxin B is preferentially used IV as it is available as the active drug allowing for more straight-forward dosing and more favorable pharmacokinetics.
Adverse effects of polymyxins?
- Nephrotoxicity
2. Neurotoxicity
Mechanism of action of fosfomycin?
It interferes with cell wall synthesis in both Gram-positive and Gram-negative bacteria by inhibiting the initial step involving phosphoenolpyruvate synthetase. Fosfomycin enters the cells of fosfomycin-susceptible bacteria by means of two different transport uptake systems and inhibits the synthesis of peptidoglycan by blocking the formation of N-acetylmuramic acid from N-acetylglucosamine and phosphoenolpyruvate.
Spectrum of fosfomycin?
Broad spectrum.
How is fosfomycin administered?
Oral. Take on empty stomach.
Adverse effects of fosfomycin?
- GI disturbances
What is metronidazole used for?
Anti Protozoa and antibacterial (ANAEROBES) -> used as second line for CDAD
Mechanism of action of metronidazole?
The nitro group of metronidazole is able to serve as an electron acceptor, forming cytotoxic free radicals that results in protein and DNA damage, and death of the E. histolytica trophozoites.
How is metronidazole administered?
Oral.
How is metronidazole cleared?
Hepatic.
