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Short answer What does it treat? How do you take it? Side effects to know Who should not take it? When is it an emergency? What a Pymander AI doctor consult looks like Common questions Sources Related questionsCefdinir is a cephalosporin antibiotic - it kills the bacteria behind common respiratory and skin infections.
It is a workhorse for ear infections, sinus infections, and strep, with two quirks people always ask about: red stools and a birth-control interaction.
What does it treat?
Bacterial infections including bronchitis, pneumonia, and infections of the skin, ears, sinuses, throat, and tonsils. It kills bacteria; it does nothing for colds, flu, or other viruses.
How do you take it?
With or without food, every 12 or 24 hours depending on what is being treated, for 5 to 10 days - same times every day. Capsules come as 300 mg; shake the suspension before each use. Two spacing rules: antacids containing magnesium or aluminum, iron supplements, and iron-containing multivitamins go 2 hours before or 2 hours after cefdinir. And the famous quirk: it can turn stools reddish, especially alongside iron - harmless, but nobody warns you. Finish the whole course even when you feel better. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
Common: vomiting, nausea, stomach pain, diarrhea, headache, vaginal itching, and reddish-colored stools.
Serious - call your doctor immediately or get emergency care: rash, hives, swelling of the face, throat, tongue, lips, or eyes, and difficulty breathing or swallowing.
Who should not take it?
Anyone allergic to cefdinir or other cephalosporins - and penicillin allergy goes on the list too, since cross-reactions exist. Flag gastrointestinal disease, especially colitis, and kidney disease. If you have diabetes, the suspension contains sugar. And the birth-control rule: cefdinir may decrease the effectiveness of hormonal contraceptives - pills, patches, rings, and injections - so a backup method for the course. If you become pregnant, call your doctor.
When is it an emergency?
In an emergency, call 911Trouble breathing or swallowing, or swelling of the face, tongue, or throat, is a 911 call. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
How our AI doctor decides when to send you to care ›What a Pymander AI doctor consult looks like
Common questions
Why is my poop red on cefdinir?
Almost certainly the drug, not blood. MedlinePlus lists reddish-colored stools among cefdinir's common effects - it is a known, harmless interaction, especially with iron in your diet or supplements. The versions that are not harmless - watery or bloody stools with cramps or fever - come with symptoms you cannot miss and mean calling your doctor.
Why do I have to separate cefdinir from my iron supplement?
Iron binds it in the gut and blocks absorption. MedlinePlus says antacids with magnesium or aluminum, iron supplements, and iron-containing multivitamins go 2 hours before or 2 hours after cefdinir. Same window, three common products - check your multivitamin label.
Does cefdinir affect birth control?
It can. MedlinePlus says cefdinir may decrease the effectiveness of hormonal contraceptives - pills, patches, rings, and injections - and that you will need another method while taking it. Sort the backup before the first dose.
I am allergic to penicillin - can I take cefdinir?
Tell your doctor before the first dose, not after. Cefdinir is a cephalosporin, a cousin of penicillin, and MedlinePlus says to disclose allergy to any cephalosporin or to penicillin antibiotics. Many penicillin-allergic people take cephalosporins safely, but that call belongs to your prescriber with your specific reaction history.
Why is the suspension a problem for diabetics?
It is sweetened with sucrose. MedlinePlus says if you have diabetes, you should know the cefdinir suspension contains sugar - relevant to glucose control and worth factoring into your monitoring during the course.
What happens if I miss a dose of cefdinir?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up. With a 5-to-10-day course, the finish line is close - the complete course is what makes the infection stay gone.