Prescription medication · Macrocyclic Antibiotic
fidaxomicin
Also sold as Dificid. Fidaxomicin treats diarrhea caused by Clostridioides difficile (C.
Data updated 2026-05-15
- 2,273
- FDA reportsRarely reported
- 1
- InteractionFew interactions
- $238.77
- Brand price (NADAC)
What the data shows
fidaxomicin (Dificid) is a prescription Macrocyclic Antibiotic, among the least-reported drugs the FDA tracks (2,273 FDA reports), with 1 documented drug interaction.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
fidaxomicin (Dificid) is a prescription Macrocyclic Antibiotic. Fidaxomicin treats diarrhea caused by Clostridioides difficile (C.
Fidaxomicin is an antibiotic medicine. It is used to treat diarrhea caused by a bacteria called C. difficile.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Brand Price
$238.77/unit
Generic Available
Yes (3 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Fidaxomicin treats diarrhea caused by Clostridioides difficile (C.
Common side effects
Nausea, Vomiting, Abdominal pain
Key warnings
Do not take fidaxomicin if you are allergic to it or any of its ingredients.
The sections below are summarized in plain English from fidaxomicin's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Fidaxomicin is a macrolide antibacterial drug. It works by stopping the growth of C. difficile bacteria in your gut. This helps to relieve diarrhea and other symptoms caused by the infection.
How to Take It
Take one 200 mg tablet twice a day. Take it by mouth for 10 days. You can take it with or without food.
This is a plain-language summary of fidaxomicin's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
It is not known if fidaxomicin will harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if fidaxomicin passes into breast milk. Talk to your doctor about the best way to feed your baby if you take this medicine.
This is a plain-language summary of fidaxomicin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is close to your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of fidaxomicin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store fidaxomicin tablets at room temperature, between 68°F to 77°F, in the original bottle.
Side Effects (from patient reports)
Based on 2,273 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for fidaxomicin, by number of reports
- Clostridium Difficile Infection
Clostridium Difficile Infection
461 reports
- Diarrhoea
Diarrhoea
339 reports
- Disease Recurrence 178
Disease Recurrence
178 reports
- Clostridium Difficile Colitis 156
Clostridium Difficile Colitis
156 reports
- Nausea 120
Nausea
120 reports
- Treatment Failure 119
Treatment Failure
119 reports
- Abdominal Pain 85
Abdominal Pain
85 reports
- Pyrexia 74
Pyrexia
74 reports
- Death 69
Death
69 reports
- Vomiting 69
Vomiting
69 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for fidaxomicin each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where fidaxomicin sits
fidaxomicin has more FDA adverse-event reports than 14% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is fidaxomicin; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 2,273 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2011–2025.
Total Reports
2,273
Reports Mentioning Death
248
10.9% of reports — not proof of cause
Hospitalization Reports
699
Top Indication
Clostridium Difficile Infection
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | CLOSTRIDIUM DIFFICILE INFECTION | 461 |
| 3 | DIARRHOEA | 339 |
| 4 | DISEASE RECURRENCE | 178 |
| 5 | CLOSTRIDIUM DIFFICILE COLITIS | 156 |
| 7 | NAUSEA | 120 |
| 8 | TREATMENT FAILURE | 119 |
| 9 | ABDOMINAL PAIN | 85 |
| 11 | PYREXIA | 74 |
| 12 | DEATH | 69 |
| 13 | VOMITING | 69 |
| 14 | FATIGUE | 55 |
| 15 | ACUTE KIDNEY INJURY | 52 |
| 18 | CLOSTRIDIUM TEST POSITIVE | 46 |
| 19 | DYSPNOEA | 44 |
| 20 | MALAISE | 44 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Do not take fidaxomicin if you are allergic to it or any of its ingredients. Allergic reactions can include trouble breathing, rash, itching, and swelling of the face, mouth, or throat. If you have a severe allergic reaction, stop taking fidaxomicin and get medical help right away.
Known Drug Interactions
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 )].
Mechanism: Cyclosporine blocks the proteins that help remove fidaxomicin from your system, which raises the amount of fidaxomicin in your blood.
What to do: Your doctor may monitor you for side effects, but no specific dose changes are usually required.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
What is fidaxomicin used for?
How often do I take fidaxomicin?
Can I take fidaxomicin with food?
What should I do if I miss a dose?
What are the common side effects?
Can I take fidaxomicin if I'm allergic to other antibiotics?
Is fidaxomicin safe during pregnancy?
Can I breastfeed while taking fidaxomicin?
How should I store fidaxomicin?
What if I have a severe allergic reaction?
What are the common side effects of fidaxomicin?
Does fidaxomicin interact with other medications?
What drug class is fidaxomicin?
Is fidaxomicin safe during pregnancy?
Related Medications in Macrocyclic Antibiotic
Other drugs grouped near fidaxomicin - same-class peers and common alternatives.
amikacin
Amikin
Amikacin is an antibiotic medicine.
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amoxicillin
Amoxil
Amoxicillin and Clavulanate Potassium is a combination medicine used to fight bacterial infections.
Compare with fidaxomicin →
amoxicillin/clavulanate
Augmentin
Augmentin is a combination of two medicines, amoxicillin and clavulanate.
Compare with fidaxomicin →
ampicillin/sulbactam
Unasyn
Unasyn is a combination of two antibiotics that fights bacteria in your body.
Compare with fidaxomicin →
azithromycin
Zithromax, Z-Pack
Azithromycin is an antibiotic that fights bacteria.
Compare with fidaxomicin →
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What the FDA Data Shows for fidaxomicin
The FDA label for fidaxomicin (sold under brand names such as Dificid) classifies it as a prescription-only medication in the Macrocyclic Antibiotic class. Fidaxomicin treats diarrhea caused by Clostridioides difficile (C. Official labeling lists 6 commonly reported side effects, including Nausea, Vomiting, Abdominal pain.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 2,273 voluntary reports. The database also lists 1 documented drug interaction derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: January 28, 2026
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages