fidaxomicin

fidaxomicin

Dificid

Pharmacologic class: Macrolide

Therapeutic class: Anti-infective

Pregnancy risk category B

Action

Bactericidal against Clostridium difficile in vitro, inhibiting RNA synthesis by RNA polymerases

Availability

Tablets: 200 mg

Indications and dosages

➣ C. difficile-associated diarrhea

Adults: 200-mg tablet P.O. b.i.d. for 10 days

Contraindications

None

Precautions

Use cautiously in:

• systemic infections or absence of proven or strongly suspected C. difficile infection

• pregnant or breastfeeding patients

• children younger than age 18 (safety and efficacy not established).

Administration

• Administer with or without food.

• Be aware that using drug in absence of proven or strongly suspected C. difficile infection is unlikely to provide benefit to patient and increases risk of development of drug-resistant bacteria.

• Be aware that drug has minimal systemic absorption and isn't effective in treatment of systemic infections.

Adverse reactions

GI: nausea, vomiting, abdominal pain, GI hemorrhage

Hematologic: anemia, neutropenia

Interactions

Drug-drug. Cyclosporine: increased plasma concentrations of fidaxomicin and its metabolite

Patient monitoring

• Monitor CBC periodically.

• Observe patient for signs and symptoms of GI hemorrhage.

Patient teaching

• Tell patient to take drug with or without food.

• Inform patient that drug only treats C. difficile-associated diarrhea and shouldn't be used to treat other infections.

• Inform patient that although it's common to feel better early in the course of therapy, the drug should be taken exactly as directed. Skipping doses or not completing full course of therapy may decrease effectiveness of immediate treatment and increase likelihood that bacteria will develop resistance and won't be treatable by this drug or other antibacterials in the future.

☞ Instruct patient to promptly report signs and symptoms of GI bleeding.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs mentioned above.

fidaxomicin

(fi-dax-oh-mye-sin) ,

Dificid

(trade name)

Classification

Therapeutic: anti infectives
Pharmacologic: macrolides

Pregnancy Category: B

Indications

Treatment of diarrhea associated with Clostridium difficile.

Action

Bactericial action mostly against clostridia; inhibits RNA synthesis.

Acts locally in the GI tract to eliminate Clostridium difficile.

Therapeutic effects

Elimination of diarrhea caused by Clostridium difficile.

Pharmacokinetics

Absorption: Minimal systemic absorption.

Distribution: Stays primarily in the GI tract.

Metabolism and Excretion: Mostly transformed via hydrolysis in the GI tract to OP-1118, its active metabolite. Eliminated mostly (>92%) in feces: <1% excreted in urine.

Half-life: Fidaxomicin—11.7 hr; OP-1118—11.2 hr.

Time/action profile

ROUTE	ONSET	PEAK	DURATION
PO	unknown	unknown	unknown

Contraindications/Precautions

Contraindicated in: Hypersensitivity.

Use Cautiously in: Obstetric / Lactation: Use during pregnancy only if clearly needed, use cautiously during lactation; Pediatric: Safe and effective use in children <18 yr has not been established.

Adverse Reactions/Side Effects

Gastrointestinal

• GI hemorrhage (life-threatening)
• nausea (most frequent)
• abdominal pain

Hematologic

• anemia
• neutropenia

Miscellaneous

• hypersensitivity reactions (life-threatening)

Interactions

Drug-Drug interaction

No significant interactions noted.

Route/Dosage

Oral (Adults >18 yr) 200 mg twice daily for 10 days.

Availability

Tablets: 200 mg

Nursing implications

Nursing assessment

• Monitor bowel function for diarrhea, abdominal cramping, fever, and bloody stools. May begin up to several weeks following cessation of antibiotic therapy.
• Monitor for signs and symptoms of hypersensitivity reactions (dyspnea, pruritus, rash, angioedema of mouth, throat, and face) periodically during therapy. Risk increases with a macrolide allergy.
• Lab Test Considerations: May cause ↑ serum alkaline phosphatase, and hepatic enzymes.
  • May cause ↓ serum bicarbonate, ↓ platelet count, anemia, and neutropenia.
  • May cause hyperglycemia and metabolic acidosis.

Potential Nursing Diagnoses

Risk for infection (Indications)
Diarrhea (Indications)

Implementation

• Oral: Administer twice daily without regard to food.

Patient/Family Teaching

• Instruct patient to take fidamoxicin as directed for the full course of therapy, even if feeling better. Skipping doses or not completing full course of therapy may decrease effectiveness of therapy and increase risk that bacteria will develop resistance and not be treatable in the future.
• Advise female patients to notify health care professional if pregnancy is planned or suspected or if breast feeding.

Evaluation/Desired Outcomes

• Decrease in diarrhea caused by Clostridium difficile.