Key takeaways
Cefdinir (Omnicef) and penicillin V potassium (Penicillin VK) are both antibiotics used to treat bacterial infections, including strep throat and certain skin infections. However, they belong to different medication classes. Cefdinir is a cephalosporin antibiotic, while penicillin V potassium is a penicillin antibiotic. Cefdinir is available as capsules and oral suspension, typically taken once or twice a day, whereas penicillin V potassium comes in tablets and suspension, usually taken three to four times daily. Cefdinir is often used off-label for urinary tract infections, especially in children, while penicillin V potassium is not used for this purpose. Common side effects of both medications include diarrhea, nausea, and vomiting. Both medications can cause serious allergic reactions, especially if you have a history of allergies to similar antibiotics. Cefdinir should not be taken with certain antacids or iron supplements, while penicillin V potassium should not be combined with other antibiotics unless prescribed together.
