Co-amoxiclav
- Generic name
- amoxicillin and clavulanate potassium
- Brand names
- Augmentin (US, international), Curam, Amoxiclav Multichem (New Zealand)
- Drug class
- Penicillin Antibiotic + Beta-Lactamase Inhibitor Combination
- Form
- Tablet (250/500/875 mg combinations), oral suspension, extended-release tablet
- Route
- Oral
- Legal status
- Prescription only. Confirmed Authorised in all 5 countries checked.
Supply Rules Vary
Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand
Australia: Augmentin Duo / Augmentin Duo Forte (and generics) (4) · Full directory
What amoxicillin and clavulanate potassium is and how it works
Co-amoxiclav combines amoxicillin with clavulanate, extending amoxicillin's effectiveness to bacteria that would otherwise resist it. It treats infections of the lungs, ears, sinuses, skin, and urinary tract. (1)
The most important real safety issue with this specific combination is a risk of liver problems (hepatotoxicity) tied specifically to the clavulanate component — this is a genuinely higher risk than with amoxicillin alone, though still uncommon overall.
Mechanism of action: how amoxicillin and clavulanate potassium works
Amoxicillin inhibits bacterial cell wall synthesis; clavulanate irreversibly inhibits bacterial beta-lactamase enzymes, protecting amoxicillin from degradation and extending its spectrum. Amoxicillin half-life ~1.3h, clavulanic acid ~1h; peak levels at 1-1.5h; 50-70% amoxicillin and 25-40% clavulanic acid excreted unchanged in urine within 6 hours. (1)
What amoxicillin and clavulanate potassium is used for
Lower respiratory tract infections
Treats infections such as pneumonia and bronchitis caused by susceptible, including beta-lactamase-producing, bacteria. (1)
Acute bacterial otitis media
Treats middle-ear infections. (1)
Sinusitis
Treats acute bacterial sinus infections. (1)
Skin and skin-structure infections
Treats bacterial skin infections. (1)
Urinary tract infections
Treats UTIs caused by susceptible, including beta-lactamase-producing, bacteria. (1)
Before taking amoxicillin and clavulanate potassium
Do not take / not appropriate for
- Do not take co-amoxiclav if you have had a serious allergic reaction (such as anaphylaxis or a severe skin reaction) to amoxicillin, clavulanate, or other beta-lactam antibiotics. (serious beta-lactam hypersensitivity) (1)
- Do not take co-amoxiclav if you have ever had jaundice or liver problems specifically linked to a previous course of amoxicillin/clavulanate — this is a real, specific contraindication, not just a general caution. (prior amoxicillin/clavulanate-associated liver injury) (1)
Tell your clinician about
- Any allergy to penicillin or other antibiotics.
- Any history of liver problems, especially with a previous antibiotic.
- Any kidney disease.
- If you take allopurinol, oral contraceptives, probenecid, or warfarin.
- If you are pregnant, planning pregnancy, or breastfeeding.
How to take amoxicillin and clavulanate potassium
- Standard adult dose is 500mg every 12 hours or 250mg every 8 hours; for more severe infections, 875mg every 12 hours or 500mg every 8 hours.
- Pediatric dosing is weight-based and depends on age — infants under 12 weeks require a specific lower-strength suspension.
- Complete the full course even if you feel better before finishing it.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5)
Missed dose
Take the missed dose as soon as you remember; skip it if it's almost time for the next dose. Do not double up. Contact your pharmacist if unsure.
Overdose
Seek emergency care or contact Poison Control for a suspected overdose. (1)
Side effects
Diarrhea is the most common side effect and becomes more likely at higher doses.
Diarrhea/loose stools, nausea, rash/hives, vomiting, vaginal irritation
What to notice: Diarrhea occurred in about 9% of people, nausea in 3%, rash/urticaria in 3%.
What to do: Mention persistent or severe symptoms to your clinician. (1)
Liver problems (hepatotoxicity/cholestatic jaundice) — a real, specific risk of this combination
What to notice: Yellowing of the skin or eyes, dark urine, pale stools, unusual fatigue, or upper abdominal pain. Usually reversible, but has rarely been fatal.
What to do: Contact your clinician promptly; seek urgent care for jaundice. (1)
C. difficile-associated diarrhea
What to notice: Watery or bloody diarrhea, during or after treatment.
What to do: Contact your clinician promptly. (1)
Serious warnings
Hepatotoxicity/cholestatic jaundice — real, clavulanate-specific risk — serious
Symptoms: Yellowing of the skin/eyes, dark urine, pale stools, fatigue.
Action: Contact your clinician promptly for these symptoms. If you have ever had this reaction to amoxicillin/clavulanate before, do not take it again — tell every future prescriber. (1)
C. difficile-associated diarrhea — serious
Symptoms: Watery or bloody diarrhea.
Action: Contact your clinician promptly. (1)
Serious allergic reactions — emergency
Symptoms: Anaphylaxis or severe skin reactions (e.g. Stevens-Johnson syndrome).
Action: Seek emergency care immediately. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Allopurinol | Increases the likelihood of a skin rash when combined with amoxicillin. | Mention this combination to your clinician. (1) |
| Oral contraceptives | May reduce contraceptive effectiveness by affecting gut bacteria. | Discuss backup contraception with your clinician during treatment. (1) |
| Probenecid | Increases amoxicillin blood levels. | Combining these is not generally recommended. (1) |
| Warfarin | May prolong prothrombin time/INR. | Your clinician will monitor INR more closely if these are combined. (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Renal impairment
The 875mg tablet strength should be avoided if kidney function is significantly reduced (GFR below 30); dosing intervals are adjusted for severe impairment. (1)
Children, including infants under 12 weeks
Dosing is weight-based and age-specific; infants under 12 weeks require a specific lower-strength suspension formulation, not an adult or general pediatric dose. (1)
Pregnancy
Animal studies have not shown fetal harm; use if clearly needed, as directed by your prescriber. (1)
Breastfeeding
Amoxicillin passes into breast milk; exercise caution and discuss with your prescriber and your baby's healthcare provider. (1)
Monitoring
Before starting
- Review any history of penicillin allergy or prior liver reaction to amoxicillin/clavulanate specifically.
- Review kidney function.
- Review current medicines, especially allopurinol, oral contraceptives, probenecid, and warfarin.
During treatment
- Watch for signs of liver problems (jaundice, dark urine, pale stools).
- Watch for diarrhea, including delayed-onset diarrhea after the course ends.
- Watch for allergic reaction signs.
Storage
Store at controlled room temperature per the product's specific packaging instructions; reconstituted suspension typically requires refrigeration and has a limited shelf life — follow the pharmacy label.
Study the drug class: Penicillins
Professional information
Clinician-facing context only. Non-US product, brand, and supply information is limited to what is explicitly documented in country-brand-verification.json and country-supply-classification.json.
United States
Indication: Full real indication list above
Dose summary: 500mg q12h or 250mg q8h standard; 875mg q12h or 500mg q8h for severe infections; pediatric 25-45mg/kg/day (12wk+) or 30mg/kg/day (neonates <12wk, specific suspension).
Renal context: Avoid 875mg tablet if GFR<30; adjust intervals for severe impairment. (1)
United Kingdom
Indication: Authorised — real CO-AMOXICLAV product listings confirmed (625mg tablets, 1000/200mg injection).
Dose summary: Not itemized in this pass.
Renal context: Not itemized. (3)
Australia
Indication: Authorised — Augmentin Duo/Duo Forte, real ARTG numbers and PBS verification dates confirmed.
Dose summary: Not itemized in this pass.
Renal context: Not itemized. (4)
Canada
Indication: Authorised — 88 real combination products confirmed via direct DPD API query.
Dose summary: Not itemized in this pass.
Renal context: Not itemized. (2)
New Zealand
Indication: Authorised — three independent current Medsafe data sheets confirmed (Augmentin, Curam, Amoxiclav Multichem).
Dose summary: Not itemized in this pass.
Renal context: Not itemized. (5)
Hepatic guidance
Real, clavulanate-specific hepatotoxicity risk (hepatitis, cholestatic jaundice) — usually reversible, deaths have been reported. A prior episode with this combination is a contraindication to future use.
Overdose note
Supportive care and poison control guidance. (1)
Frequently asked questions
Why does co-amoxiclav carry a liver-injury warning that plain amoxicillin doesn't?
The added clavulanate component is specifically associated with a real, if uncommon, risk of liver injury (hepatitis or cholestatic jaundice), usually reversible. This risk is much lower with amoxicillin alone. If you've ever had this reaction to amoxicillin/clavulanate before, you should not take it again. (1)
Does co-amoxiclav affect birth control pills?
It may reduce the effectiveness of oral contraceptives by affecting gut bacteria. Discuss backup contraception with your clinician during treatment. (1)
What is clavulanate for?
Clavulanate itself doesn't kill bacteria — it blocks an enzyme (beta-lactamase) that some bacteria use to destroy amoxicillin, allowing amoxicillin to work against bacteria that would otherwise resist it. (1)
What is the mechanism of action of amoxicillin and clavulanate potassium?
Amoxicillin inhibits bacterial cell wall synthesis; clavulanate irreversibly inhibits bacterial beta-lactamase enzymes, protecting amoxicillin from degradation and extending its spectrum. Amoxicillin half-life ~1.3h, clavulanic acid ~1h; peak levels at 1-1.5h; 50-70% amoxicillin and 25-40% clavulanic acid excreted unchanged in urine within 6 hours. (1)
What is the generic name of Co-amoxiclav?
The generic name is amoxicillin and clavulanate potassium. It is sold under brand names including Augmentin (US, international), Curam, Amoxiclav Multichem (New Zealand). (1)
What class of drug is amoxicillin and clavulanate potassium?
Co-amoxiclav is classed as: Penicillin Antibiotic + Beta-Lactamase Inhibitor Combination. (1)
References
- AUGMENTIN (amoxicillin and clavulanate potassium) — prescribing informationDailyMed / FDA · United States · accessed 2026-07-27 · source 1
- DPD active-ingredient query for clavulanate (88 combination products)Health Canada DPD, public API · Canada · accessed 2026-07-27 · source 2
- CO-AMOXICLAV and AMOXICILLIN AND CLAVULANIC ACID substance/product entriesMHRA Products · United Kingdom · accessed 2026-07-27 · source 3
- Augmentin Duo, Augmentin Duo Forte, and multiple generic brands — ARTG-registered, PBS-verifiedTherapeutic Goods Administration (Australia) / Healthdirect · Australia · accessed 2026-07-27 · source 4
- Augmentin, Curam, and Amoxiclav Multichem — current New Zealand Data Sheets (3 independent products)Medsafe (New Zealand) · New Zealand · accessed 2026-07-27 · source 5
Brand names by country
Single-ingredient amoxicillin and clavulanate potassium names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Augmentin (and generics) (1)FDA approved currently labeled · 250 mg, 500 mg, 875 mg, ES-600 suspension · multiple
United Kingdom
- Co-amoxiclav (generic, multiple) (3)MHRA licensed · 625 mg, 1000/200 mg injection · multiple
Canada
- Amoxicillin/clavulanate (generic, multiple manufacturers) (2)currently listed 88 real products · various · multiple
Australia
- Augmentin Duo / Augmentin Duo Forte (and generics) (4)ARTG registered PBS verified · 500/125 mg, 875/125 mg · multiple
New Zealand
- Augmentin; Curam; Amoxiclav Multichem (5)current medsafe data sheets three products · 125mg/31.25mg per 5mL, 500mg/125mg tablet · multiple