Metronidazole

Metronidazole is a specific antibiotic used for anaerobic bacteria and protozoa. These bacteria and parasites share an anaerobic niche in the lumen of the bowel or vagina (1). It is an imidazole derivative and acts as either an antibacterial or antiprotozoal (1). Metronidazole is known commonly by the brand name Flagyl, and it is taken orally or topically. Flagyl topical gel is used to cure rosacea, or acne, and vaginal gel is used for bacterial vaginosis. The pill has a bitter taste, so it is best taken with some type of juice. It works by killing bacteria or preventing further growth. Side effects for Flagyl are dizziness, headache, nausea, stomach pain, loss of appetite, and constipation. Flagyl also causes major problems when mixed with alcohol. Mixing Flagyl and alcohol will cause extreme nausea and vomiting. Clostridium difficile is commonly treated by Flagyl and C. difficile causes colon inflammation and diarrhea (1). Flagyl also treats against vaginal infections (bacterial vaginosis), Crohn's disease (inflammatory bowel disease), stomach ulcers (H. pylori), and Giardiasis (parasite infection in the intestines) (2). Metronidazole is inactive until it is metabolized within the host or microbial cells, and it only becomes active when it is reduced. In these bacteria or parasites, metronidazole is activated when it receives an electron from ferredoxin or flavodoxin (3). An example of bacteria inhibition is seen when Metronidazole inhibits Helicobater pylori by inhibiting the expression of Flagellin (2). Without the presence of flagella, the Helicobacter pylori become nonmotile and can no longer function. This is a prime example as to why Flagyl is so effective against stomach ulcers.

References:
1."Metronidazole (Oral Route)." Mayo Clinic. Mayo Foundation for Medical Education and Research, 01 Jan. 2012. Web. 27 Nov. 2013.
2. Kamiya, S. "Microbiology (metabolism,physiology)." Helicobacter 8 (2003): n. pag. Web. 27 Nov. 2013.
3. Samuelson, John. "American Society for MicrobiologyAntimicrobial Agents and Chemotherapy." Why Metronidazole Is Active against Both Bacteria and Parasites. N.p., n.d. Web. 27 Nov. 2013.