Overview
11 DESCRIPTION Fidaxomicin tablets (fidaxomicin) is a macrolide antibacterial drug for oral administration. Its CAS chemical name is Oxacyclooctadeca-3,5,9,13,15-pentaen-2-one, 3-[[[6-deoxy-4- O -(3,5-dichloro-2-ethyl-4,6-dihydroxybenzoyl)-2- O -methyl-β-D-mannopyranosyl]oxy]methyl]-12-[[6-deoxy-5- C -methyl-4- O -(2-methyl-1-oxopropyl)-β-D- lyxo -hexopyranosyl]oxy]-11-ethyl-8-hydroxy-18-[(1 R...
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Fidaxomicin is an antibacterial drug [see Microbiology ( 12.4 )]. 12.2 Pharmacodynamics Fidaxomicin acts locally in the gastrointestinal tract on C. difficile. In a dose-ranging trial (N=48) of fidaxomicin using 50 mg, 100 mg, and 200 mg twice daily for 10 days, a dose-response relationship was observed for efficacy. 12.3 Pharmacokinetics The pharmacokinetic parameters of fidaxomicin and its main metabolite OP-1118 following a single dose of 200 mg in healthy adult males (N=14) are summarized in Table 4. Table 4: Mean (± Standard Deviation) Pharmacokinetic Parameters of Fidaxomicin 200 mg in Healthy Adult Males Parameter Fidaxomicin OP- 1118 N Value N Value C max (ng/mL) 14 5.20 ± 2.81 14 12.0 ± 6.06 T max (h)* 14 2.00 (1.00-5.00) 14 1.
Indications
- 1 INDICATIONS AND USAGE Fidaxomicin tablets are a macrolide antibacterial indicated in adult patients for the treatment of C. difficile -associated diarrhea. ( 1.1 ) To reduce the development of drug-resistant bacteria and maintain the effectiveness of fidaxomicin tablets and other antibacterial drugs, fidaxomicin tablets should be used only to treat infections that are proven or strongly suspected to be caused by C. difficile. ( 1.2 ) 1.1 Clostridioides difficile -Associated Diarrhea Fidaxomicin tablets are indicated in adult patients for the treatment of C.
Common Doses
- 200 mg
Dosage
2 DOSAGE AND ADMINISTRATION Fidaxomicin tablets are administered orally with or without food. ( 2.1 ) Adults One 200 mg tablet orally twice daily for 10 days. ( 2.2 ) 2.1 Important Administration Instructions Fidaxomicin tablets are available for oral administration as 200 mg tablets. Fidaxomicin tablets are administered orally with or without food. 2.2 Adult Patients The recommended dosage for adults is one 200 mg fidaxomicin tablet orally twice daily for 10 days. Pediatric use information is approved for Cubist Pharmaceuticals LLC's DIFICID ® (fidaxomicin) tablets.
Contraindications
- 4 CONTRAINDICATIONS Fidaxomicin tablets are contraindicated in patients who have known hypersensitivity to fidaxomicin or any other ingredient in fidaxomicin tablets [see Warnings and Precautions ( 5.1 )]. Fidaxomicin tablets are contraindicated in patients who have known hypersensitivity to fidaxomicin or any other ingredient in fidaxomicin tablets. ( 4 )
Side Effects
- 6 ADVERSE REACTIONS The most common adverse reactions in adults (incidence ≥2%) are nausea, vomiting, abdominal pain, gastrointestinal hemorrhage, anemia, and neutropenia. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Apotex Corp., at 1-800-706-5575 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in...
Interactions
- 7 DRUG INTERACTIONS Fidaxomicin and its main metabolite, OP-1118, are substrates of the efflux transporter, P-glycoprotein (P-gp), which is expressed in the gastrointestinal tract. 7.1 Cyclosporine Cyclosporine is an inhibitor of multiple transporters, including P-gp. When cyclosporine was co-administered with fidaxomicin tablets, plasma concentrations of fidaxomicin and OP-1118 were significantly increased but remained in the ng/mL range [see Clinical Pharmacology ( 12.3 )]. Concentrations of fidaxomicin and OP-1118 may also be decreased at the site of action (i.e.