Cefdinir — Compare Prices at US & Canada Pharmacies

• Cefdinir is a third-generation cephalosporin antibiotic prescribed to treat bacterial infections including bronchitis, sinusitis, sore throat, and urinary tract infections.
• Frequently reported side effects include diarrhea, vomiting, headache, vaginal yeast infection, and rash; serious but uncommon reactions may include severe allergic responses, Stevens-Johnson syndrome, and C. difficile colitis.
• Cefdinir can affect laboratory test results, potentially raising blood glucose levels and liver enzyme values.
• Risk of side effects can be minimized by taking the medication exactly as prescribed, informing your healthcare provider of all existing conditions and current medications, and completing the entire prescribed course.

Cefdinir (brand name Omnicef) belongs to a class of antibiotics called third-generation cephalosporins. It is used to treat several types of bacterial infections, including bronchitis, sinusitis, pharyngitis (sore throat), and urinary tract infections. The medication works by eliminating harmful bacteria throughout the body. Available in capsule and oral suspension forms, cefdinir is typically prescribed for up to 10 days depending on the infection type.

Most patients tolerate cefdinir well, though side effects do occur. The most frequently encountered effects include diarrhea, vomiting, and headache. Serious adverse reactions exist but are uncommon and may include severe allergic reactions, Stevens-Johnson syndrome, and Clostridium difficile (C. difficile) infections. Because drug interactions are possible, inform your healthcare provider of any medical conditions or medications you take before starting cefdinir treatment.

Patients receiving cefdinir commonly experience the following side effects:

Diarrhea, yeast infection (candidiasis), nausea and vomiting, headache, abdominal pain, vaginal inflammation (vaginitis), rash, and indigestion or gas are among the most frequently reported effects.

Laboratory testing may also show clinically meaningful changes during treatment:

Elevated white blood cells in the urine, increased urinary protein (proteinuria), microscopic blood in the urine (microhematuria), elevated blood glucose, high eosinophil levels (eosinophilia—a specific type of white blood cell), and raised liver enzymes including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) may all be detected on lab work.

Diarrhea. The most frequently reported side effect — 15% of adults and adolescents in clinical trials, 8% of children overall, and up to 17% in children under 2. Contact your provider if it becomes severe, since that can signal a C. difficile infection that needs different treatment.

Yeast infection. Cefdinir can disrupt the body's normal bacterial balance, leading to oral thrush or a vaginal yeast infection. In one large trial of women taking 600 mg daily, 4% developed a vaginal yeast infection; in a separate pediatric study, 0.3% of girls developed one and 0.9% of all children developed a fungal skin infection.

Although uncommon, serious adverse reactions can occur. These include severe allergic reactions (anaphylaxis), Stevens-Johnson syndrome (presenting as flu-like illness with painful rash and blistering), toxic epidermal necrolysis (rare condition involving skin peeling and blistering), exfoliative dermatitis (widespread skin redness and peeling), C. difficile infection with severe diarrhea and colitis, low neutrophil counts (neutropenia), low platelets (thrombocytopenia), hemolytic anemia, aplastic anemia, severe immune reactions (serum sickness), kidney damage, and liver toxicity.

Rash can accompany several cefdinir-related conditions, including allergic reactions, Stevens-Johnson syndrome, toxic epidermal necrolysis, and exfoliative dermatitis. Trial data show rash occurred in 0.9% of adults and adolescents taking cefdinir, while 3% of children experienced rash—predominantly those younger than 2 years.

Seek immediate emergency care if rash occurs alongside wheezing, chest or throat tightness, or difficulty breathing, as these signs may indicate a serious allergic reaction.

Cefdinir can eliminate protective bacteria in the gut microbiota, allowing C. difficile organisms to proliferate unchecked. These bacteria produce toxins that inflame the large intestine lining, a condition called pseudomembranous colitis. The resulting diarrhea ranges from mild to life-threatening, with symptoms including frequent watery or bloody diarrhea, abdominal pain and tenderness, cramping, nausea, fever, and loss of appetite.

Most cefdinir side effects resolve during treatment or shortly after stopping the medication, though some require additional care. Yeast infections, oral thrush, and C. difficile infections often need separate treatment with other medications.

Severe allergic reactions demand immediate medical attention. Warning signs include rash or hives, swollen or blistered skin areas, red peeling skin, wheezing, chest tightness, swelling of the mouth, face, lips, throat or tongue, and difficulty breathing.

• Kidney disease. A creatinine clearance below 30 mL/min may call for a lower dose — cephalosporins have been linked to seizures in people with kidney impairment whose dose wasn't adjusted.
• Colitis. A history of colitis calls for closer monitoring, since C. difficile-associated diarrhea can be more severe in that group if it develops.
• Diabetes. Cefdinir can raise blood sugar on its own, and the liquid suspension contains sugar too — diabetic patients are generally advised to avoid the suspension and to monitor glucose carefully if cefdinir is needed.
• Older age. Despite the theoretical concern of more chronic conditions, clinical trials actually found cefdinir well tolerated in older adults, with lower side-effect rates than in younger adults.
• Children. FDA-approved for children as young as 2 months, for ear infections, sinusitis, pharyngitis, tonsillitis, pneumonia, and bacterial skin infections.
• Pregnancy. Older FDA pregnancy category B — no human safety data exist, but animal studies showed no known risk. Talk to your provider about your specific situation before taking it while pregnant.
• Breastfeeding. Considered compatible; there's no direct human data on the nursing infant, but data from other cephalosporins suggests no significant risk. Effects on milk supply aren't known.
• Overdose. Symptoms can include nausea, vomiting, stomach pain, diarrhea, and seizures — seek emergency care or contact Poison Control if you suspect an overdose.

Cefdinir can interact with several medications and supplements. Inform your healthcare provider of all drugs, vitamins, and supplements you are taking before starting treatment.

Antacids containing magnesium or iron supplements may reduce cefdinir absorption and should be taken at least 2 hours before or after the antibiotic. Patients taking iron may notice reddish-colored stools, which results from a complex formed between cefdinir and iron in the digestive tract and is not related to bleeding.

Probenecid, used to treat gout by lowering uric acid, may increase cefdinir levels in the bloodstream. Hormonal birth control methods may be less effective during cefdinir therapy; backup contraception is recommended. Tetracycline antibiotics may alter how cefdinir functions in the body when taken concurrently.

Several measures can minimize the risk of unwanted cefdinir effects. Follow your healthcare provider's and pharmacist's directions precisely. If taking the liquid formulation, shake well before each use and measure doses with an appropriate syringe.

Cefdinir may be taken with or without food, though taking it with food can reduce stomach upset. Do not skip doses. If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose—in which case skip the missed dose. Never double up to compensate for a missed dose, as this increases the risk of side effects.

Avoid taking antacids or supplements containing magnesium or iron within 2 hours before or after your cefdinir dose, as these interfere with medication absorption. Disclose all medical conditions to your provider, as cefdinir may not be appropriate for certain health situations. If you have experienced allergic reactions to cephalosporin antibiotics, inform your provider before use.

Provide a complete medication list to your healthcare provider before treatment begins, including prescription drugs, over-the-counter products, supplements, and herbal remedies, as drug interactions are possible. Complete your entire prescribed course even if symptoms improve, since stopping early risks infection recurrence and antibiotic resistance.

Store cefdinir at room temperature, away from moisture, heat, and children's access. Discard any unused medication after your treatment ends.

Not typically. Cefdinir isn't on the FDA-approved indication list for urinary tract infections — it's approved for community-acquired pneumonia, bronchitis flare-ups, sinusitis, strep throat/tonsillitis, uncomplicated skin infections, and (in children) ear infections. If you have a standard bladder infection, your provider is more likely to prescribe an antibiotic specifically suited to the urinary tract, like cephalexin, nitrofurantoin, or a sulfa drug. If cefdinir has been prescribed for a urinary symptom, it's worth asking your provider what's actually being treated.

There's no documented severe interaction between cefdinir and alcohol — it's not in the same category as metronidazole or similar drugs that can cause a genuinely dangerous reaction. Still, drinking can make cefdinir's common side effects (nausea, diarrhea) worse and won't help your recovery, so it's best kept light or avoided until you finish your course.

Unlike some liquid antibiotics, the cefdinir oral suspension does not need to be refrigerated — it's stable at room temperature for the full 10 days it's typically prescribed for. Shake it well before each dose and discard any unused suspension once your course is done.