Metronidazole Flashcards
Please note that the drug card information is for Educational Use ONLY, and the source is from Carrie Bowman's glossary of drug cards permitted by use of Georgetown NAP students. No permission is given to use these cards for anything other than as a study resource for our program.
What is the trade name for metronidazole?
Flagyl
What is the formal drug classification of metronidazole?
-The injection is the parenteral dosage form of the synthetic antibacterial agent 1-(beta-hydroxyethyl)-2-methyl-5-nitroimadazole
What are the clinical uses of metronidazole?
-it is active in vitro against most obligate anaerobes
What does metronidazole NOT have any significant effects against?
facultative anaerobes or obligate aerobes
Which organisms is metronidazole effective against?
- Anaerobic gram negative bacilli: Bacteroides species and the Fusobacterium species
- Anaerobic gram positive bacilli: Clostridium species and susceptible strains of Eubacterium
- Anaerobic gram positive cocci: Peptococcus species and Peptostreptococcus species
What is the MOA of metronidazole?
- metronidazole is broken down and activated by anaerobic organisms to a compound that damages the parasite
- metronidazole is inactive until it is reduced within the host or microbial cell via an interaction with reduced ferredoxin or with specific nitroreductases
- the activated form of metronidazole forms reduced cytotoxic compounds that bind to proteins, membranes and leading to severe damage to the host organism
What makes metronidazole sensitive for ameba and anaerobic organisms?
-due to the presence of PFOR activity that is lacking in most eukaryotes and eubacteria; however, poorly oxygenated tissues such as abscesses can activate metronidazole
What is the elimination half life of metronidazole?
8 hrs in health adults; newborn infants have a diminished capacity to eliminate it
How is metronidazole metabolized?
30-60% is metabolized by the liver
-metronidazole is the major component found in plasma with its 2-hydroxymethyl metabolite making up the lesser component
How is metronidazole eliminated?
-major route of elimination (60-80%) is via urine with fecal elimination accounting for 6-15%
What are the major metabolites that appear in the urine? what do they come from?
- they come from side chain oxidation
- 1-(beta-hydroxyethyl)-2-hydroxymethyl-5-nitroimidazole-1hy-acetic acid; holy cow this better now be something we need to know!
- glucuronide conjugation, with unchanged metronidazole accounting for 20% of the total
Is metronidazole protein bound?
Less than 20% of the circulating metronidazole is bound to plasma protein
What is the volume of distribution of metronidazole?
distributed rapidly throughout the tissues reaching high concentration in bodily fluids such as CSF, saliva and breast milk (concentrations in these bodily fluids are similar to that in plasma)
- also distributed to saliva, bile, seminal fluids, bone, liver and liver abscesses, lung and vaginal secretions
- also crosses the BBB and placenta
With regards to a single dose of Metronidazole, how does decreased renal function alter it?
decreased renal function dose not alter the single dose pharmacokinetics of metronidazole; however, plasma clearance is decreased in patients with decreased liver function
Can metronidazole be removed by dialysis?
YES
What are the CNS side effects of metronidazole?
Convulsive seizures encephalopathy aseptic meningitis optic and peripheral neuropathy Ataxia Confusion Impaired Coordination Dizziness Headache Insomnia Irritibilit Vertigo
What are the endocrine/metabolic side effects of metronidazole?
Disulfiram-like reaction
Dysmenorrhea
Libido Decreased