Description

Simple

A medication used to treat a wide variety of infections in the body as well as inflammation and redness of the skin.

Clinical

A nitroimidazole used to treat trichomoniasis, amebiasis, inflammatory lesions of rosacea, and bacterial infections, as well as prevent postoperative infections.

Overview

Metronidazole is a commonly used antibiotic, belonging to the nitroimidazole class of antibiotics.[14] It is frequently used to treat gastrointestinal infections as well as trichomoniasis and giardiasis, and amebiasis which are parasitic infections.[4,A18039] Metronidazole has been used as an antibiotic for several decades[15], with added antiparasitic properties that set it apart from many other antibacterial drugs, allowing it to treat a wide variety of infections. It is available in capsule form, tablet form, and topical form, and suppository preparations for the treatment of various infections.

Pharmacology

Indication

Metronidazole is indicated for the treatment of confirmed trichomoniasis caused by Trichomonas vaginalis (except for in the first trimester of pregnancy) and the patient's sexual partners, bacterial vaginosis[16]... Read more

Pharmacodynamic

Metronidazole treats amebiasis, trichomoniasis, and giardiasis, exerting both antibacterial and antiprotozoal activities.[16] Metronidazole is an effective treatment for some anaerobic bacterial infections.[ Read more

Mechanism of action

The exact mechanism of action of metronidazole has not been fully established, however, it is possible that an intermediate in the reduction of metronidazole which is only made by anaerobic bacteria and protozoa, binds deoxyribonucleic acid and electron-transport proteins of organisms, blocking nucl... Read more

Absorption

After the intravenous infusion of a 1.5g dose, peak concentration was reached within 1 hour and was peak level of 30-40 mg/L.[16] When a multiple-dose regimen of 500mg three times a day administered intravenously... Read more

Protein binding

Metronidazole is less than 20% bound to plasma proteins.[ Read more

Volume of distribution

Metronidazole is widely distributed throughout the body[ Read more

Clearance

Dose adjustments may be required in patients with hepatic impairment, as clearance is impaired in these patients.[16] The clearance of metronidazole in the kidneys is estimated at 10 mL/min/1.73 m2.[ Read more

Half life

The elimination half-life of metronidazole is 7.3 ± 1.0 after a single 500mg IV dose in healthy subjects.[16] Another resource indicates that the elimination half-life for metronidazole ranges from 6 to 10 hours... Read more

Route of elimination

Metronidazole and metabolites are 60 to 80% eliminated in the urine, and 6-15% excreted in the feces.[ Read more

Toxicity

LD50 information

The oral LD50 of metronidazole in rats is 5000 mg/kg [16]

Overdose information

Adverse effects that may be exaggerated with an overdose include peripheral neuropathy, central nervous sy... Read more

Adverse Effects

Contraindications

  • Regions: US
  • Patient Conditions:
      • Name: Pregnancy Trimester, First
      • Drugbank Id: DBCOND0006255
  • Regions: US
  • Patient Conditions:
      • Name: Hypersensitivity to nitroimidazoles
      • Drugbank Id: DBCOND0121375
  • Regions: US
  • Patient Conditions:
      • Name: Hypersensitivity to metronidazole
      • Drugbank Id: DBCOND0121374

Food Interactions

  • Avoid alcohol.
  • Take with food. Food reduces irritation.

Interactions

Type in a drug name to check for interaction with Metronidazole
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  • Paracetamol(acetaminophen)
  • Paxil(paroxetine)
  • Pamelor(nortriptyline)
  • Panadol(acetaminophen)
  • Patanol(olopatadine ophthalmic)
  • Pataday(olopatadine ophthalmic)
  • Parnate(tranylcypromine)
  • Pazeo(olopatadine ophthalmic)
(R)-warfarin
The serum concentration of (R)-warfarin can be increased when it is combined with Metronidazole.
(S)-Warfarin
The serum concentration of (S)-Warfarin can be increased when it is combined with Metronidazole.
4-hydroxycoumarin
The metabolism of 4-hydroxycoumarin can be decreased when combined with Metronidazole.
5-fluorouridine
The serum concentration of 5-fluorouridine can be increased when it is combined with Metronidazole.
7-Nitroindazole
The therapeutic efficacy of 7-Nitroindazole can be decreased when used in combination with Metronidazole.
9-aminocamptothecin
The metabolism of 9-aminocamptothecin can be decreased when combined with Metronidazole.
Abatacept
The metabolism of Metronidazole can be increased when combined with Abatacept.
Abexinostat
The risk or severity of QTc prolongation can be increased when Metronidazole is combined with Abexinostat.
Acalabrutinib
The metabolism of Metronidazole can be decreased when combined with Acalabrutinib.
Acebutolol
The risk or severity of QTc prolongation can be increased when Metronidazole is combined with Acebutolol.
Acenocoumarol
The serum concentration of Acenocoumarol can be increased when it is combined with Metronidazole.
Aceprometazine
The risk or severity of QTc prolongation can be increased when Metronidazole is combined with Aceprometazine.
Acetazolamide
The therapeutic efficacy of Acetazolamide can be decreased when used in combination with Metronidazole.
Acetohexamide
The metabolism of Acetohexamide can be decreased when combined with Metronidazole.
Acetyldigoxin
The risk or severity of QTc prolongation can be increased when Metronidazole is combined with Acetyldigoxin.
Acetylsalicylic acid
The metabolism of Acetylsalicylic acid can be decreased when combined with Metronidazole.
Acrivastine
The risk or severity of QTc prolongation can be increased when Metronidazole is combined with Acrivastine.
Adalimumab
The metabolism of Metronidazole can be increased when combined with Adalimumab.
Adenine
The metabolism of Metronidazole can be decreased when combined with Adenine.
Adenosine
The risk or severity of QTc prolongation can be increased when Metronidazole is combined with Adenosine.
17 References
  1. 1 . Shennan A, Crawshaw S, Briley A, Hawken J, Seed P, Jones G, Poston L: A randomised controlled trial of metronidazole for the prevention of preterm birth in women positive for cervicovaginal fetal fibronectin: the PREMET Study. BJOG. 2006 Jan;113(1):65-74.PubMed: 16398774
  2. 2 . Williams CS, Woodcock KR: Do ethanol and metronidazole interact to produce a disulfiram-like reaction? Ann Pharmacother. 2000 Feb;34(2):255-7.PubMed: 10676835
  3. 3 . Visapaa JP, Tillonen JS, Kaihovaara PS, Salaspuro MP: Lack of disulfiram-like reaction with metronidazole and ethanol. Ann Pharmacother. 2002 Jun;36(6):971-4.PubMed: 12022894
  4. 4 . Dingsdag SA, Hunter N: Metronidazole: an update on metabolism, structure-cytotoxicity and resistance mechanisms. J Antimicrob Chemother. 2018 Feb 1;73(2):265-279. doi: 10.1093/jac/dkx351.PubMed: 29077920
  5. 5 . Hernandez Ceruelos A, Romero-Quezada LC, Ruvalcaba Ledezma JC, Lopez Contreras L: Therapeutic uses of metronidazole and its side effects: an update. Eur Rev Med Pharmacol Sci. 2019 Jan;23(1):397-401. doi: 10.26355/eurrev_201901_16788.PubMed: 30657582
  6. 6 . Sprandel KA, Schriever CA, Pendland SL, Quinn JP, Gotfried MH, Hackett S, Graham MB, Danziger LH, Rodvold KA: Pharmacokinetics and pharmacodynamics of intravenous levofloxacin at 750 milligrams and various doses of metronidazole in healthy adult subjects. Antimicrob Agents Chemother. 2004 Dec;48(12):4597-605. doi: 10.1128/AAC.48.12.4597-4605.2004.PubMed: 15561831
  7. 7 . Lamp KC, Freeman CD, Klutman NE, Lacy MK: Pharmacokinetics and pharmacodynamics of the nitroimidazole antimicrobials. Clin Pharmacokinet. 1999 May;36(5):353-73. doi: 10.2165/00003088-199936050-00004.PubMed: 10384859
  8. 8 . Morales-Leon F, von Plessing-Rossel C, Villa-Zapata L, Fernandez-Rocca P, Sanhueza-Sanhueza C, Bello-Toledo H, Mella-Montecinos S: [Pharmacokinetics/pharmacodinamic (PK/PD) evaluation of a short course of oral administration of metronidazole for the management of infections caused by Bacteroides fragilis]. Rev Chilena Infectol. 2015 Apr;32(2):135-41. doi: 10.4067/S0716-10182015000300001.PubMed: 26065445
  9. 9 . Lau AH, Lam NP, Piscitelli SC, Wilkes L, Danziger LH: Clinical pharmacokinetics of metronidazole and other nitroimidazole anti-infectives. Clin Pharmacokinet. 1992 Nov;23(5):328-64. doi: 10.2165/00003088-199223050-00002.PubMed: 1478003
  10. 10 . Kapoor K, Chandra M, Nag D, Paliwal JK, Gupta RC, Saxena RC: Evaluation of metronidazole toxicity: a prospective study. Int J Clin Pharmacol Res. 1999;19(3):83-8.PubMed: 10761537
  11. 11 . Lofmark S, Edlund C, Nord CE: Metronidazole is still the drug of choice for treatment of anaerobic infections. Clin Infect Dis. 2010 Jan 1;50 Suppl 1:S16-23. doi: 10.1086/647939.PubMed: 20067388
  12. 12 . Loesche WJ, Schmidt E, Smith BA, Morrison EC, Caffesse R, Hujoel PP: Effects of metronidazole on periodontal treatment needs. J Periodontol. 1991 Apr;62(4):247-57. doi: 10.1902/jop.1991.62.4.247.PubMed: 2037955
  13. 13 . Pearce RE, Cohen-Wolkowiez M, Sampson MR, Kearns GL: The role of human cytochrome P450 enzymes in the formation of 2-hydroxymetronidazole: CYP2A6 is the high affinity (low Km) catalyst. Drug Metab Dispos. 2013 Sep;41(9):1686-94. doi: 10.1124/dmd.113.052548. Epub 2013 Jun 27.PubMed: 23813797
  14. 14 . Flagyl (Metronidazole) FDA Label Link
  15. 15 . FDA approvals, Metronidazole Link
  16. 16 . Canadian monograph, Flagyl Link
  17. 17 . Flagyl Link