What Is Dificid?

Dificid (Fidaxomicin) is a prescription macrolide antibiotic used to treat diarrhea caused by Clostridioides difficile (C. diff) infection in adults and children ages 6 months and older.

C. diff is a bacterium that can cause severe, sometimes life-threatening diarrhea — most commonly after a course of broad-spectrum antibiotics disrupts the normal balance of gut bacteria. Dificid works by killing C. diff bacteria specifically, while largely preserving the beneficial bacteria in your digestive tract. This narrow-spectrum approach is what sets Dificid apart from older C. diff treatments.

Brand Name, Generic, and Manufacturer

Here are the key details:

• Brand name: Dificid
• Generic name: Fidaxomicin
• Drug class: Macrolide antibiotic
• Manufacturer (brand): Merck & Co., Inc.
• Generic manufacturer: Teva Pharmaceuticals (launched July 2025)
• FDA approval: Originally approved in May 2011 for adults; expanded in March 2025 to include children ages 6 months and older
• DEA schedule: Not a controlled substance
• Available forms: 200 mg oral tablets and oral suspension (40 mg/mL powder for suspension)

The availability of a generic version from Teva is significant — it makes Fidaxomicin more accessible and affordable for many patients. For more on cost, see the pricing section below.

What Is Dificid Used For?

Dificid is FDA-approved for one specific condition:

Clostridioides difficile-associated diarrhea (CDAD)

C. diff infection typically occurs when:

• You've recently taken antibiotics (which can disrupt normal gut bacteria)
• You've been hospitalized or lived in a long-term care facility
• You're over 65 years old
• You have a weakened immune system

Symptoms of C. diff include watery diarrhea (3 or more loose stools per day), fever, abdominal pain or cramping, loss of appetite, and nausea. In severe cases, it can lead to life-threatening inflammation of the colon.

Dificid is not effective for treating other types of infections. Because it has minimal absorption into the bloodstream, it stays in the gastrointestinal tract where C. diff lives. It should not be used for systemic bacterial infections.

Doctors may prescribe Dificid for a first episode of C. diff or, more commonly, for recurrent C. diff infections — cases where the infection comes back after initial treatment with another antibiotic like Vancomycin. Clinical studies have shown that Dificid is associated with lower recurrence rates compared to Vancomycin. For more on how this works, read our guide on how Dificid works.

How Is Dificid Taken?

Dificid is taken by mouth. Here's what you need to know about dosing:

Adults

• Dose: 200 mg twice daily
• Duration: 10 days
• With or without food: Dificid can be taken with or without food
• Swallow whole: Do not crush, break, or chew the tablets

Children (6 Months and Older)

• Tablets: Children weighing at least 12.5 kg (about 27.5 lbs) who can swallow tablets take 200 mg twice daily for 10 days
• Oral suspension: Children who cannot swallow tablets use the liquid suspension. The dose is weight-based (typically 2 to 5 mL twice daily for 10 days) and determined by the child's doctor
• Storage: Mixed oral suspension must be refrigerated and used within 12 days

Important Dosing Tips

• Complete the full course: Even if you feel better after a few days, finish all 10 days of treatment. Stopping early increases the risk of recurrence.
• Missed dose: If you miss a dose, take it as soon as you remember. If it's almost time for your next dose, skip the missed one — do not double up.
• Do not take anti-diarrheal medications (like Imodium) without your doctor's approval, as they can make C. diff worse.

Who Should Not Take Dificid?

Dificid is not appropriate for everyone. You should not take Dificid if:

• You are allergic to Fidaxomicin or any ingredients in the medication
• You have a history of allergy to macrolide antibiotics — such as Azithromycin (Zithromax), Clarithromycin (Biaxin), or Erythromycin. Tell your doctor about any prior antibiotic allergies.

Talk to your doctor before taking Dificid if:

• You are pregnant or planning to become pregnant (limited data available)
• You are breastfeeding (it's unknown if Fidaxomicin passes into breast milk)
• You have a systemic (non-gut) infection — Dificid is not absorbed into the bloodstream and won't treat infections outside the GI tract

For information about potential interactions with other medications, see our guide on Dificid drug interactions. For side effect details, visit our Dificid side effects guide.

How Much Does Dificid Cost?

Dificid is one of the more expensive antibiotics on the market. Here's what you can expect to pay in 2026:

• Brand-name Dificid (200 mg tablets, 20-count): Approximately $5,100 retail price without insurance
• Generic Fidaxomicin (Teva, 200 mg tablets, 20-count): Around $1,293 with a GoodRx coupon
• Oral suspension (brand): Approximately $5,092 for 136 mL

With insurance, your out-of-pocket cost will depend on your plan's formulary, tier placement, and whether prior authorization is required. Many insurance plans cover Dificid but place it on a specialty or high-cost tier.

Ways to Save

• Ask for generic Fidaxomicin — The Teva generic can save you thousands compared to brand-name Dificid.
• Manufacturer savings coupon — Merck offers a savings coupon at dificid.com for eligible commercially insured patients.
• Teva copay card — Teva offers a copay card for generic Fidaxomicin where eligible patients may pay as little as $50 out of pocket.
• Discount cards — GoodRx, SingleCare, and Optum Perks all offer coupons that can significantly reduce the price at participating pharmacies.
• Patient assistance programs — NeedyMeds and the Medicine Assistance Tool can help uninsured or underinsured patients find financial help.

For a complete breakdown, see our guide on how to save money on Dificid.

Final Thoughts

Dificid (Fidaxomicin) is a targeted, effective antibiotic specifically designed to treat C. diff infections. Its narrow spectrum of activity means it kills C. diff while preserving your gut's healthy bacteria — which is why it's associated with lower recurrence rates than older treatments like Vancomycin.

With the launch of a generic version in 2025, Dificid has become more affordable and accessible. If you've been prescribed Dificid, use Medfinder to find a pharmacy near you that has it in stock, and explore savings options to keep your out-of-pocket cost as low as possible.