Dificid Sus
It is used to treat diarrhea caused by a bacterial infection called C diff.
Drug Class
Macrolide antibiotic
Pharmacologic Class
RNA polymerase inhibitor
Pregnancy Category
Category B
FDA Approved
Jan 2020
DEA Schedule
Not Controlled
Overview
What is this medicine?
Fidaxomicin is an antibiotic used to treat a severe type of diarrhea caused by a bacteria called Clostridioides difficile (C. diff). It works by killing the C. diff bacteria in your gut, helping to stop the diarrhea and other symptoms.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take your medication as directed, with or without food, and continue using it even if your symptoms improve. Before taking your dose, remove the medication from the refrigerator 15 minutes in advance. Do not heat or microwave the medication.
To ensure accurate dosing, shake the medication well before use and measure the liquid dose carefully using the provided measuring device. If a measuring device is not included, ask your pharmacist for one. After taking your dose, replace the cap on the medication.
Storing and Disposing of Your Medication
Store your medication in the refrigerator at all times, but do not freeze it. After the medication has been mixed, discard any unused portion after 12 days. Keep the medication in its original container to maintain its potency and safety.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed dose.
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take your medication as directed, with or without food, and continue using it even if your symptoms improve. Before taking your dose, remove the medication from the refrigerator 15 minutes in advance. Do not heat or microwave the medication.
To ensure accurate dosing, shake the medication well before use and measure the liquid dose carefully using the provided measuring device. If a measuring device is not included, ask your pharmacist for one. After taking your dose, replace the cap on the medication.
Storing and Disposing of Your Medication
Store your medication in the refrigerator at all times, but do not freeze it. After the medication has been mixed, discard any unused portion after 12 days. Keep the medication in its original container to maintain its potency and safety.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed dose.
Lifestyle & Tips
- Stay well-hydrated by drinking plenty of fluids, especially if you have ongoing diarrhea.
- Maintain good hand hygiene to prevent the spread of C. diff.
- Complete the entire course of medication as prescribed, even if you start feeling better.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
200 mg orally twice daily for 10 days
Dose Range:
200 - 200 mg
Condition-Specific Dosing:
Clostridioides difficile-associated diarrhea (CDAD):
200 mg orally twice daily for 10 days
Pediatric Dosing
Neonatal:
Not established (for suspension, specific dosing for <4 months is available)
Infant:
For infants < 4 months: 160 mg/m² orally twice daily for 10 days (maximum 200 mg per dose). For infants ≥ 4 months: 11 mg/kg orally twice daily for 10 days (maximum 200 mg per dose).
Child:
11 mg/kg orally twice daily for 10 days (maximum 200 mg per dose)
Adolescent:
200 mg orally twice daily for 10 days
Dose Adjustments
Renal Impairment:
Mild:
No dose adjustment recommended
Moderate:
No dose adjustment recommended
Severe:
No dose adjustment recommended
Dialysis:
No dose adjustment recommended; fidaxomicin is minimally absorbed systemically.
Hepatic Impairment:
Mild:
No dose adjustment recommended
Moderate:
No dose adjustment recommended
Severe:
No dose adjustment recommended
Pharmacology
Mechanism of Action
Fidaxomicin is a macrocyclic antibacterial drug that acts locally in the gastrointestinal tract. It exerts its bactericidal activity by inhibiting bacterial RNA polymerase, specifically targeting the sigma subunit of RNA polymerase in Clostridioides difficile, leading to inhibition of RNA synthesis and cell death.
Pharmacokinetics
Absorption:
Bioavailability:
< 1% (systemic)
Tmax:
1-4 hours (for the small amount absorbed)
FoodEffect:
Can be administered with or without food. Food does not significantly affect systemic exposure.
Distribution:
Vd:
Not clinically relevant due to minimal systemic absorption and local GI action
ProteinBinding:
91-97% (for the small amount absorbed)
CnssPenetration:
Limited
Elimination:
HalfLife:
11.7 hours (fidaxomicin), 10.9 hours (OP-1118) (systemic, but not clinically relevant)
Clearance:
Not clinically relevant due to minimal systemic absorption
ExcretionRoute:
Primarily fecal excretion (>92% of dose)
Unchanged:
>92% (excreted in feces as parent drug and metabolite)
Pharmacodynamics
OnsetOfAction:
Clinical improvement typically seen within 2-3 days
PeakEffect:
Not applicable (local GI action)
DurationOfAction:
Sustained local activity in the GI tract for the duration of treatment
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor immediately or seek emergency medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Shortness of breath
Black, tarry, or bloody stools
Vomiting blood or coffee ground-like material
Feeling extremely tired or weak
Fever or chills
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or persist, contact your doctor for guidance:
For all patients taking this medication:
+ Stomach pain
+ Upset stomach or vomiting
For children:
+ Diarrhea
+ Constipation
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor immediately or seek emergency medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Shortness of breath
Black, tarry, or bloody stools
Vomiting blood or coffee ground-like material
Feeling extremely tired or weak
Fever or chills
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or persist, contact your doctor for guidance:
For all patients taking this medication:
+ Stomach pain
+ Upset stomach or vomiting
For children:
+ Diarrhea
+ Constipation
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Worsening or persistent diarrhea after starting the medication
- Signs of dehydration (e.g., extreme thirst, decreased urination, dizziness, lightheadedness)
- Severe abdominal pain or bloating
- Fever that does not improve or worsens
- Any new or unusual symptoms
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Describe the allergic reaction you experienced, including any symptoms that occurred.
This medication may interact with other medications or health conditions. To ensure safe use, disclose all your medications (including prescription and over-the-counter drugs, natural products, and vitamins) and health problems to your doctor and pharmacist. Carefully review your medications and health conditions to confirm it is safe to take this medication. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
It is essential to inform your doctor about any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Describe the allergic reaction you experienced, including any symptoms that occurred.
This medication may interact with other medications or health conditions. To ensure safe use, disclose all your medications (including prescription and over-the-counter drugs, natural products, and vitamins) and health problems to your doctor and pharmacist. Carefully review your medications and health conditions to confirm it is safe to take this medication. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. To minimize the risk of a second infection, do not use this drug for a longer period than prescribed. If you are pregnant, planning to become pregnant, or are breastfeeding, notify your doctor immediately. Your doctor will discuss the potential benefits and risks of this medication with you, considering both your health and the health of your baby, to determine the best course of action.
Overdose Information
Overdose Symptoms:
- Due to minimal systemic absorption, overdose is unlikely to cause systemic toxicity. Gastrointestinal upset (e.g., nausea, vomiting, diarrhea) might occur.
What to Do:
In case of suspected overdose, contact a poison control center immediately (e.g., 1-800-222-1222 in the US) or seek emergency medical attention. Treatment is generally supportive.
Drug Interactions
Moderate Interactions
- P-glycoprotein (P-gp) inhibitors (e.g., cyclosporine, ketoconazole, verapamil, amiodarone, quinidine)
Monitoring
Baseline Monitoring
Diagnosis of Clostridioides difficile infection (CDI)
Rationale: To confirm the indication for treatment.
Timing: Prior to initiation of therapy
Routine Monitoring
Resolution of diarrhea and other CDI symptoms
Frequency: Daily during treatment
Target: Absence of symptoms
Action Threshold: Persistent or worsening symptoms may indicate treatment failure or recurrence, requiring re-evaluation.
Symptom Monitoring
- Diarrhea frequency and consistency
- Abdominal pain or cramping
- Fever
- Signs of dehydration (e.g., dry mouth, decreased urination, dizziness)
Special Patient Groups
Pregnancy
Fidaxomicin is classified as Pregnancy Category B. Animal studies have not shown harm to the fetus, and due to minimal systemic absorption, maternal use is not expected to result in fetal exposure.
Trimester-Specific Risks:
First Trimester:
Low risk due to minimal systemic absorption.
Second Trimester:
Low risk due to minimal systemic absorption.
Third Trimester:
Low risk due to minimal systemic absorption.
Lactation
Fidaxomicin is considered L3 (Moderately Safe) by LactMed. Due to minimal systemic absorption, it is unlikely to be excreted in breast milk in clinically significant amounts, and therefore, unlikely to cause adverse effects in a breastfed infant. However, monitor the infant for potential changes in gut flora (e.g., diarrhea, candidiasis).
Infant Risk:
Low risk
Pediatric Use
Fidaxomicin suspension is approved for use in pediatric patients of all ages, including neonates, for the treatment of Clostridioides difficile-associated diarrhea (CDAD). Dosing is weight- or body surface area-based for younger children. Safety and efficacy have been established.
Geriatric Use
No dose adjustment is necessary for elderly patients. Clinical studies included a significant number of patients aged 65 and older, and no overall differences in safety or effectiveness were observed compared to younger adults. Fidaxomicin's minimal systemic absorption makes it a suitable option for this population, especially those with comorbidities or polypharmacy.
Clinical Information
Clinical Pearls
- Fidaxomicin is a highly effective, locally acting antibiotic specifically for Clostridioides difficile infection (CDI), including recurrent CDI.
- Its minimal systemic absorption reduces the risk of systemic side effects and drug interactions compared to systemically absorbed antibiotics.
- The suspension formulation is crucial for pediatric patients and those unable to swallow tablets.
- Ensure patients complete the full 10-day course, even if symptoms improve, to minimize recurrence risk.
- It is not effective for infections outside the gastrointestinal tract.
- Shake the suspension well before each use and use an accurate oral dosing syringe.
Alternative Therapies
- Oral Vancomycin (for Clostridioides difficile infection)
- Metronidazole (for mild to moderate initial Clostridioides difficile infection, though less effective than fidaxomicin or vancomycin for severe or recurrent cases)
Cost & Coverage
Average Cost:
Very high (e.g., >$5,000 - $6,000) per 10-day course
Insurance Coverage:
Specialty Tier / Non-preferred (requires prior authorization and/or step therapy)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.