Cefdinir Is a Prescription Antibiotic Used to Treat Common Bacterial Infections

Cefdinir is a third-generation cephalosporin antibiotic that treats bacterial infections of the ears, sinuses, throat, lungs, and skin. It's one of the most commonly prescribed oral antibiotics in the United States, available as a generic medication in capsule and liquid suspension forms.

This guide covers everything you need to know about Cefdinir — what it treats, how to take it, who should avoid it, and what it costs in 2026.

What Is Cefdinir?

Cefdinir is the generic name for a broad-spectrum antibiotic originally sold under the brand name Omnicef (now discontinued). It belongs to the cephalosporin class of antibiotics, which are related to penicillin but work slightly differently.

Key facts about Cefdinir:

• Drug class: Third-generation cephalosporin antibiotic
• Brand name: Omnicef (discontinued by Abbott/AbbVie)
• Generic: Yes — manufactured by Lupin, Aurobindo, Sandoz, Teva, and others
• Controlled substance: No
• Available forms: 300 mg capsules, 125 mg/5 mL oral suspension, 250 mg/5 mL oral suspension

To learn how Cefdinir works at a molecular level, see our guide on how Cefdinir works.

What Is Cefdinir Used For?

Cefdinir is FDA-approved to treat the following bacterial infections:

• Acute bacterial otitis media (middle ear infections)
• Acute maxillary sinusitis (sinus infections)
• Pharyngitis and tonsillitis (strep throat)
• Acute exacerbations of chronic bronchitis
• Community-acquired pneumonia
• Uncomplicated skin and skin structure infections

Doctors sometimes prescribe Cefdinir off-label for urinary tract infections (UTIs) and as an alternative treatment for Lyme disease, though these are not its primary uses.

Important: Cefdinir only works against bacterial infections. It will not treat viral infections like the common cold or flu.

How Is Cefdinir Taken?

The typical dosing for Cefdinir is:

Adults and Adolescents (13 years and older)

• 300 mg twice daily, or
• 600 mg once daily
• Treatment duration: 5–10 days depending on the infection

Children (6 months to 12 years)

• 7 mg/kg twice daily, or
• 14 mg/kg once daily
• Maximum dose: 600 mg per day

How to Take It Properly

• Can be taken with or without food
• Swallow capsules whole
• Shake the oral suspension well before each dose
• Take doses at evenly spaced intervals
• Complete the full course even if you feel better — stopping early increases the risk of antibiotic resistance
• Separate from antacids and iron supplements by at least 2 hours

Who Should Not Take Cefdinir?

Cefdinir is not appropriate for everyone. Do not take it if you:

• Have a known allergy to Cefdinir or other cephalosporin antibiotics
• Have had a severe allergic reaction (anaphylaxis) to any beta-lactam antibiotic, including Penicillin (though cross-reactivity is only about 1–3%, your doctor will weigh the risks)

Tell your doctor if you have:

• Kidney problems — dose adjustment is needed if your creatinine clearance is below 30 mL/min. Hemodialysis patients typically take 300 mg every other day.
• A history of GI disease, especially colitis
• Are pregnant or breastfeeding — Cefdinir is Pregnancy Category B (likely safe, but discuss with your doctor). Small amounts pass into breast milk.

For a full list of interactions, read our guide on Cefdinir drug interactions.

What Are the Side Effects?

Most people tolerate Cefdinir well. Common side effects include diarrhea (up to 15%), nausea, vomiting, stomach pain, and headache. A harmless but surprising side effect is reddish or rust-colored stools, caused by Cefdinir reacting with iron in the digestive tract.

Serious side effects are rare but include severe allergic reactions, C. difficile-associated diarrhea, and skin reactions like Stevens-Johnson syndrome. For the complete breakdown, see our guide to Cefdinir side effects.

How Much Does Cefdinir Cost?

Cefdinir is available only as a generic, which keeps costs relatively low:

• With insurance: Most patients pay $0–$15 as a copay. Cefdinir is typically on Tier 1 or Tier 2 of most formularies.
• Without insurance (retail): Around $114 for 20 capsules (300 mg) at retail price.
• With discount coupons: As low as $16 for a full course using GoodRx, SingleCare, or RxSaver.
• Oral suspension: $16–$24 retail for a 100 mL bottle.

There is no manufacturer savings program since the brand-name Omnicef has been discontinued. However, discount cards and patient assistance programs can significantly reduce your out-of-pocket cost.

Availability in 2026

Cefdinir has experienced intermittent supply shortages since 2023, especially the oral suspension formulation. Capsules are generally easier to find, but stock can vary by pharmacy and region. If your pharmacy is out of stock, use Medfinder to check availability nearby or talk to your doctor about alternatives.

Final Thoughts

Cefdinir is an effective, well-tolerated antibiotic used to treat a wide range of common bacterial infections. It's affordable as a generic, widely prescribed by primary care doctors and pediatricians, and available in both capsule and liquid forms. If you've been prescribed Cefdinir, take the full course as directed and don't hesitate to contact your doctor if you have questions about side effects or interactions.

Ready to fill your prescription? Find Cefdinir in stock near you with Medfinder.