Amoxicillin/ClavulanateAmoxicillin/Clavulanic Acid

About Amoxicillin/Clavulanate

Amoxicillin is a penicillin; clavulanate blocks the beta-lactamase enzymes some bacteria use to break it down, restoring its activity against them. Tablets treat lower respiratory, middle ear, sinus, skin and urinary tract infections in adults and children of at least 40 kg, at 500 mg every 12 hours or 250 mg every 8 hours, or 875 mg every 12 hours or 500 mg every 8 hours for severe infections. Children under 40 kg take chewable tablets or liquid dosed by weight, preferably every 12 hours, which causes less diarrhea. The extended-release tablet (two tablets every 12 hours) treats community-acquired pneumonia and acute sinusitis in people of at least 40 kg. ES-600, a stronger liquid not recommended for adults, is for children from three months weighing 8 to 40 kg: up to twelve years for acute sinusitis, and for ear infections that recur or persist after an antibiotic in the previous three months, up to two years, or up to twelve in daycare.

There is no boxed warning. It must not be taken after a serious allergic reaction to amoxicillin, clavulanate or another beta-lactam antibiotic such as a penicillin or cephalosporin, or by anyone who developed jaundice or liver problems on it before. Liver injury has been reported, more often in older people, men and longer courses; it can start during treatment or weeks after, and is usually reversible, though deaths have occurred. Diarrhea is the most common side effect, then nausea, rash and hives, vomiting and vaginitis; watery or bloody diarrhea can be Clostridioides difficile, even two months or more later. The label also warns of severe skin reactions, of the rash many people with mononucleosis get on amoxicillin, and, since 2024, of drug-induced enterocolitis syndrome: prolonged vomiting starting one to four hours after a dose, mostly in children.

Forms can be swapped only when their ratio of amoxicillin to clavulanate matches: two 250 mg tablets do not replace one 500 mg tablet, the 250 mg tablet is not swapped for the 250 mg chewable, two 500 mg tablets do not replace one extended-release tablet, and ES-600 replaces no other form. The 200 and 400 mg chewables and liquids, and ES-600, contain aspartame, a source of phenylalanine, which matters in phenylketonuria. The 875 mg dose is not used when kidney function is severely reduced, nor are the extended-release tablet and ES-600, which are also avoided with hemodialysis. A July 2026 revision merged the brand’s labels, revised indications and dosing, and added acute sinusitis to ES-600’s uses.

Taking Amoxicillin/Clavulanate

How to take it

At the start of a meal, which helps absorption of clavulanate and eases stomach upset. The extended-release tablet is not taken with a high-fat meal or crushed or chewed; if swallowing it whole is hard it can be split along its score, both halves taken right away. Chew the chewables; shake the liquid and measure it with a proper dosing device, not a kitchen spoon. Finish the course even if you feel better.

If you miss a dose

Take a missed dose when you remember, unless the next dose is almost due; then skip it. Never take two doses at once.

Storage

Tablets and unmixed powder at or below 77°F (25°C), tightly closed. Keep the mixed suspension in the refrigerator and throw away what is left after ten days. Keep it out of reach of children.

Interactions to know about

Probenecid is not recommended with it. It can raise the INR with warfarin, so clotting tests may be checked, and allopurinol makes a rash more likely. Tell the prescriber about mononucleosis, liver or kidney disease, or phenylketonuria.

This summarizes the official prescribing information. Your prescriber’s and pharmacist’s instructions, and the leaflet that comes with your medicine, take priority.

Why the cash price for Amoxicillin/Clavulanate differs from pharmacy to pharmacy

Standard generic tablets and suspensions come from more than one company and cost pharmacies little, so a course is priced mostly on the dispensing fee and markup; a prescription that names Augmentin and blocks substitution is filled at a brand price.

The extended-release tablet has only one approved generic maker, and a pharmacy may need to order it, ES-600 or a less common chewable strength. Because the forms are not interchangeable, a pharmacy out of your strength cannot make it up from smaller tablets.

Ways to pay less for Amoxicillin/Clavulanate without insurance

• Ask for generic substitution and whether it is on the pharmacy’s flat-price generic list, and compare more than one pharmacy.
• For a child’s liquid, ask for a quote that covers every bottle the full course needs.
• If the extended-release tablet or ES-600 is quoted high, ask the prescriber whether a standard tablet or liquid would suit; the pharmacist cannot make that switch alone.
• Upload the prescription to Script Unlock so licensed pharmacies can quote their cash price. You pay the pharmacy directly.

Questions to ask your pharmacist about Amoxicillin/Clavulanate

1. 1.Should I take each dose at the start of a meal?
2. 2.How long does my child’s liquid keep in the refrigerator?
3. 3.What should I do if I get diarrhea, a rash, or yellow skin or eyes?
4. 4.Does it interact with my warfarin, allopurinol or birth control pills?

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