Description

Simple

An antibiotic used to treat diarrhea caused by a type of bacteria called clostridium difficile.

Clinical

A macrolide antibiotic used to treat diarrhea associated with Clostridium difficile infection.

Overview

Fidaxomicin is a novel macrolide antibiotic used in the treatment of diarrhea caused by _Clostridioides_ (formerly _Clostridium_) _difficile_ in adult and pediatric patients over the age of 6 months.[10] Fidaxomicin is a naturally-occurring 18-member macrocycle derived from fermentation.[8] Because fidaxomicin contains an 18-membered lactone ring in its structure, it is referred to as a macrocyclic lactone antibiotic drug.[6] The antibacterial activity of fidaxomicin is distinct from macrolides and rifamycins, as the bactericidal activity is time-dependent, and not concentration-dependent.[Read more

Pharmacology

Indication

Fidaxomicin is indicated for the treatment of _Clostridioides_ (formerly _Clostridium_) _difficile_-associated diarrhea in adult and pediatric patients 6 months of age and older.[ Read more

Pharmacodynamic

Fidaxomicin has a narrow-spectrum antibacterial profile, with potent bactericidal activity specifically against C. difficile.[ Read more

Mechanism of action

_Clostridium difficile_ is a Gram-positive bacterium that causes various gastrointestinal complications, such as antibiotic-associated diarrhea. _C. difficile_ infection can be caused by antibiotic therapy, resulting in the disruption of the human gut flora leads to an overgrowth of _C. difficile_.... Read more

Absorption

Following oral administration of a single dose of 200 mg fidaxomicin in healthy adults, the Cmax of fidaxomicin and its main metabolite OP-1118 were 5.20 ± 2.81 ng/mL and 12.0 ± 6.06, respectively. The median Tmax of fidaxomicin was 2 hours. The systemic absorption of fidaxomic... Read more

Protein binding

Since fidaxomicin has minimal systemic absorption following oral administration, there is limited information on the plasma protein binding profile of fidoxamicin.

Volume of distribution

Fidaxomicin is mainly confined to the gastrointestinal tract when orally administered.[10] There is limited information on the volume of distribution of fidaxomicin.

Clearance

There is limited information on the clearance of fidaxomicin.

Half life

Following oral administration of a single dose of 200 mg fidaxomicin in healthy adults, the elimination half-life of fidaxomicin was approximately 11.7 ± 4.80 hours.[10 Read more

Route of elimination

Following oral administration, fidaxomicin is mainly excreted in feces. More than 92% of the dose was recovered in the faces as either the unchanged parent drug or metabolites in one study consisting of healthy adults receiving single doses of 200 mg and 300 mg of fidaxomicin. In another study of he... Read more

Toxicity

In rats, the LD50 of fidaxomicin was approximately 200 mg/kg and the no observed adverse effect level (NOAEL) was determined to be 62.5 mg/kg following administration of a single intravenous dose.[ Read more

Adverse Effects

Contraindications

  • Route:
    • Oral
  • Dose Form:
    • Tablet
  • Hypersensitivity:
    • true
  • Regions: US

Food Interactions

  • Take with or without food. High-fat meal decreases the Cmax of fidaxomicin and its metabolite in a clinically insignificant way.

Interactions

Type in a drug name to check for interaction with Fidaxomicin
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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 risk or severity of bleeding can be increased when Fidaxomicin is combined with (R)-warfarin.
(S)-Warfarin
The risk or severity of bleeding can be increased when Fidaxomicin is combined with (S)-Warfarin.
4-hydroxycoumarin
The risk or severity of bleeding can be increased when Fidaxomicin is combined with 4-hydroxycoumarin.
Acenocoumarol
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Acenocoumarol.
BCG vaccine
The therapeutic efficacy of BCG vaccine can be decreased when used in combination with Fidaxomicin.
Clorindione
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Clorindione.
Coumarin
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Coumarin.
Dicoumarol
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Dicoumarol.
Diphenadione
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Diphenadione.
Ethyl biscoumacetate
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Ethyl biscoumacetate.
Fluindione
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Fluindione.
Lactulose
The therapeutic efficacy of Lactulose can be decreased when used in combination with Fidaxomicin.
Phenindione
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Phenindione.
Phenprocoumon
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Phenprocoumon.
Picosulfuric acid
The therapeutic efficacy of Picosulfuric acid can be decreased when used in combination with Fidaxomicin.
Tioclomarol
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Tioclomarol.
Typhoid vaccine
The therapeutic efficacy of Typhoid vaccine can be decreased when used in combination with Fidaxomicin.
Warfarin
The risk or severity of bleeding can be increased when Fidaxomicin is combined with Warfarin.
11 References
  1. 1 . Artsimovitch I, Seddon J, Sears P: Fidaxomicin is an inhibitor of the initiation of bacterial RNA synthesis. Clin Infect Dis. 2012 Aug;55 Suppl 2:S127-31. doi: 10.1093/cid/cis358.PubMed: 22752861
  2. 2 . Crawford T, Huesgen E, Danziger L: Fidaxomicin: a novel macrocyclic antibiotic for the treatment of Clostridium difficile infection. Am J Health Syst Pharm. 2012 Jun 1;69(11):933-43. doi: 10.2146/ajhp110371.PubMed: 22610025
  3. 3 . Authors unspecified: Fidaxomicin: Difimicin; Lipiarmycin; OPT 80; OPT-80; PAR 101; PAR-101. Drugs R D. 2010;10(1):37-45. doi: 10.2165/11537730-000000000-00000.PubMed: 20509714
  4. 4 . Zhanel GG, Walkty AJ, Karlowsky JA: Fidaxomicin: A novel agent for the treatment of Clostridium difficile infection. Can J Infect Dis Med Microbiol. 2015 Nov-Dec;26(6):305-12. doi: 10.1155/2015/934594.PubMed: 26744587
  5. 5 . Weiss K, Allgren RL, Sellers S: Safety analysis of fidaxomicin in comparison with oral vancomycin for Clostridium difficile infections. Clin Infect Dis. 2012 Aug;55 Suppl 2:S110-5. doi: 10.1093/cid/cis390.PubMed: 22752858
  6. 6 . Vaishnavi C: Fidaxomicin--the new drug for Clostridium difficile infection. Indian J Med Res. 2015 Apr;141(4):398-407. doi: 10.4103/0971-5916.159251.PubMed: 26112840
  7. 7 . Louie TJ, Cannon K, Byrne B, Emery J, Ward L, Eyben M, Krulicki W: Fidaxomicin preserves the intestinal microbiome during and after treatment of Clostridium difficile infection (CDI) and reduces both toxin reexpression and recurrence of CDI. Clin Infect Dis. 2012 Aug;55 Suppl 2:S132-42. doi: 10.1093/cid/cis338.PubMed: 22752862
  8. 8 . Shue YK, Sears PS, Shangle S, Walsh RB, Lee C, Gorbach SL, Okumu F, Preston RA: Safety, tolerance, and pharmacokinetic studies of OPT-80 in healthy volunteers following single and multiple oral doses. Antimicrob Agents Chemother. 2008 Apr;52(4):1391-5. doi: 10.1128/AAC.01045-07. Epub 2008 Feb 11.PubMed: 18268081
  9. 9 . Mariani R, Maffioli SI: Bacterial RNA polymerase inhibitors: an organized overview of their structure, derivatives, biological activity and current clinical development status. Curr Med Chem. 2009;16(4):430-54. doi: 10.2174/092986709787315559.PubMed: 19199915
  10. 10 . FDA Approved Drug Products: DIFICID (fidaxomicin) tablets, for oral use Link
  11. 11 . Santa Cruz Biotechnology, Inc.: Fidaxomicin Safety Data Sheet Link