Cefdinir (Omnicef) is used for treating wide range of bacterial infections, including certain types of pneumonia, sinusitis, and certain skin infections. OMNICEF® (cefdinir) Capsules. OMNICEF® (cefdinir) Oral Suspension. To reduce the development of drug-resistant bacteria and maintain the effectiveness of OMNICEF and other antibacterial drugs, OMNICEF should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. SIDE EFFECTS Adverse Events Clinical Trials - OMNICEF Capsules (Adult and Adolescent Patients) In clinical trials, 5093 adult and adolescent patients (3841 US and 1252 non-US) were treated with the recommended dose of cefdinir capsules (600 mg/day). Cefoxitin is a cephalosporin (SEF a low spor in) antibiotic. It works by fighting bacteria in your body. Cefaclor is used to treat many kinds of bacterial infections, such as bladder infection, ear infection, skin infection, or infection of the respiratory tract. Omnicef (cefdinir) is in a group of drugs called cephalosporin (SEF a low spor in) antibiotics. It works by fighting bacteria in your body. Omnicef is used to treat many different types of infections caused by bacteria. Consumer information about the medication CEFDINIR - ORAL (Omnicef), includes side effects, drug interactions, recommended dosages, and storage information. Read more about the prescription drug CEFDINIR - ORAL. Amoxicillin passes through breast milk, but is usually considered safe for most breastfeeding women. Even though it is not known whether clavulanate potassium passes through breast milk, many healthcare providers also consider it safe for most breastfeeding women. Cefdinir is an antibiotic in the cephalosporin drug class prescribed to treat infections, for example, middle ear, tonsillitis, strep throat, bronchitis, and sinusitis. Common side effects are nausea, abdominal pain, loose stools, and vaginitis. Dosage and pregnancy and breastfeeding safety information are included. Amoxicillin is OK to take while pregnant. I'm a nurse and have a drug guide.It states the following: Distribution - Crosses the placenta and enters breast milk in low concentration Use cautiously in - renal impariment, infectious mononucleosis, heptic impairment It's a category B which is OK in pregnancy..Cat. c and D are not. How to use Omnicef Capsule. Take this medication by mouth with or without food as directed by your doctor, usually once a day or twice a day (every 12 hours).