Cefixime: what it treats, how to take it, side effects
Last updated September 3, 2026.
Cefixime is a cephalosporin antibiotic - it kills bacteria. You may know it as Suprax. Like every antibiotic: nothing for colds, flu, or any virus - and a partial course breeds the resistant kind.
What does it treat?
Certain bacterial infections - ears, sinuses, throat, lungs, and urinary tract among them.
How do you take it?
Tablet, chewable tablet, capsule, or suspension, with or without food, every 12 or 24 hours depending on the prescription - same times daily, suspension shaken well. Gonorrhea may be a single dose. Exactly as directed, and finish the full 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: diarrhea, nausea, vomiting, stomach pain, gas, and heartburn.
- Serious - call your doctor immediately or get emergency care: watery or bloody stools, stomach cramps, or fever during treatment or up to two or more months after - the C. diff pattern; the allergic set - rash, itching, hives, trouble breathing or swallowing, wheezing, swelling of face, throat, tongue, lips, or eyes; and a return of sore throat, fever, chills, or other infection signs.
Who should not take it?
A past severe penicillin reaction matters: cephalosporins are cousins - tell the prescriber the exact reaction history before the first dose. Flag kidney disease and colitis history. If you become pregnant, call your doctor.
When is it an emergency?
Throat swelling, trouble breathing, or a rapidly spreading rash 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.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
Why did my doctor ask about my penicillin allergy?
Cephalosporins and penicillins are chemical cousins - a past severe penicillin reaction raises the chance of reacting to this one too. The detail that matters is the exact reaction: a childhood rash and anaphylaxis are different conversations. Most people with mild penicillin histories tolerate cefixime - but the prescriber decides with the history, not after it.
Why does the course have to be finished?
Feeling better is the bacteria knocked down, not out: the survivors of a stopped course are the hardiest, and they regrow the infection in a resistant form. MedlinePlus states it for the class - antibiotics misused or half-used raise your risk of a later infection that resists treatment. The last tablet is the treatment; the last symptom is just a milestone.
What is the delayed-diarrhea warning?
Antibiotics disturb gut bacteria - and watery or bloody stools, cramps, or fever can follow during treatment or up to two or more months after: the C. difficile pattern. Do not self-treat that diarrhea with anti-diarrhea medicine - call your doctor first; the treatment is specific. Mild loose stools without those features are common and usually pass.
Why are there so many forms - tablet, chewable, liquid?
Same drug, different deliveries: adults usually take tablets or capsules; children take the suspension, which also runs on a different schedule. Never borrow between them - a child's twice-daily liquid and an adult's once-daily tablet are not interchangeable. The suspension gets shaken well and measured with the dosing device, not a kitchen spoon.
Can I take it with my other medications?
Mostly yes - cephalosporins are light on interactions compared to many antibiotics - but blood thinners and a few others deserve the pharmacist screen, and any probiotic or supplement routine is worth mentioning. One more: it can throw off some urine-sugar tests - diabetics using older test methods should know.
What happens if I miss a dose of cefixime?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up. Once-daily versions are forgiving of a same-day catch-up. The pattern to avoid is the stop-start course - that is the resistance factory, not the single late dose.