Dificid (Fidaxomicin) is a macrolide antibacterial agent specifically indicated for the treatment of diarrhea caused by Clostridioides difficile (CDAD). It is suitable for pediatric patients aged 6 months and above, as well as adult patients.

Precautions for Administration of Dificid (Fidaxomicin)

Dosage and Administration Method

Adults: Take 200mg tablets orally, twice a day (12 hours apart), for a 10-day treatment course. The tablets can be taken with food or on an empty stomach.

Pediatric patients (≥ 6 months old and body weight ≥ 12.5kg): 200mg tablets, administered in the same way as adults; for patients with body weight < 12.5kg or those unable to swallow tablets, oral suspension (40mg/mL) should be used, and the dosage should be adjusted based on body weight (e.g., 4-7kg: 80mg per dose; above 12.5kg: 200mg per dose).

Management of missed dose: If more than 6 hours remain until the next scheduled dose, the missed dose can be taken; otherwise, skip the missed dose. Do not take an additional dose after vomiting.

Contraindications and Precautions for Use

Absolute contraindications: Patients with hypersensitivity to fidaxomicin or any component in the preparation; concurrent use with drugs such as pethidine, tramadol, and dextromethorphan.

Populations requiring caution: Pregnant women (weigh the pros and cons); lactating women (avoid breastfeeding within 1 week after discontinuing the drug); patients with moderate to severe hepatic impairment (dose reduction or prohibition is required for Child-Pugh B/C).

Drug Interactions

P-gp inhibitors (e.g., cyclosporine): May increase the blood concentration of fidaxomicin, but no dose adjustment is needed.

Acid-suppressing drugs: Avoid concurrent use with proton pump inhibitors (PPIs) or H2 receptor antagonists. If necessary, administer the drugs at intervals (take fidaxomicin 4 hours before or 10 hours after taking the acid-suppressing drug).

Medication Monitoring for Dificid (Fidaxomicin)

Monitoring of Gastrointestinal Reactions

Common symptoms: Nausea (11%), vomiting (7%), abdominal pain (6%).

Management: Mild reactions can be treated symptomatically; for grade ≥ 3 diarrhea or vomiting, suspend medication and reduce the dose after symptom resolution.

Monitoring of Liver Function

Frequency: Before treatment, once every 3 weeks for the first 3 months of treatment, and then once a month thereafter.

Abnormality criteria: If ALT/AST > 3× upper limit of normal (ULN) accompanied by symptoms, or > 5× ULN, suspend medication; if ALT/AST > 3× ULN and bilirubin > 2× ULN, discontinue medication permanently.

Monitoring of the Hematological System

Items: Complete blood count (focus on anemia and neutropenia), creatine phosphokinase (CPK) (screen for rhabdomyolysis when myalgia or dark urine occurs).

Special precautions for children: Rash (5%), fever (13.3%), and elevated aminotransferases (5.1%).

Monitoring of Allergic Reactions

Symptoms: Difficulty breathing, angioedema, rash, pruritus.

Management: Discontinue medication immediately and administer anti-allergic treatment.