Medications Directory

Approved indications: Orally, amoxicillin and clavulanate potassium is FDA-approved to treat lower respiratory tract infections, acute bacterial otitis media, sinusitis, skin and skin-structure infections, and urinary tract infections caused by susceptible beta-lactamase–producing bacteria.

Off-label uses: Clinicians commonly prescribe this drug for human and animal bite wounds, some dental and oral infections, community-acquired pneumonia, and mixed skin or soft-tissue infections (including in people with diabetes), based on guideline support and extensive clinical experience even though these uses are not specifically listed on the FDA label.

Efficacy expectations and comparisons: When the infecting bacteria are susceptible and the dose is appropriate, symptom improvement often begins within 48 to 72 hours and typical courses last about 5 to 14 days depending on the infection; compared with amoxicillin alone, adding clavulanate broadens activity against many beta-lactamase–producing organisms such as Haemophilus influenzae, Moraxella catarrhalis, some Staphylococcus aureus, and certain Enterobacteriaceae, giving clinical cure rates that are similar to or better than many other oral options for these pathogens, but it does not treat viral illnesses like colds or influenza.

Typical adult dosing: For most infections in adults and adolescents weighing at least 40 kg, common oral regimens are 875 mg/125 mg every 12 hours or 500 mg/125 mg every 8 or 12 hours, with 250 mg/125 mg doses sometimes used for milder infections; in severe renal impairment (creatinine clearance under 30 mL/min), the 875 mg tablet should be avoided and dosing intervals extended per prescriber instructions.

Pediatric dosing: For neonates and infants younger than 12 weeks, the usual total dose is 30 mg/kg/day of the amoxicillin component divided every 12 hours; for children 12 weeks and older weighing under 40 kg, typical doses are about 25–45 mg/kg/day (amoxicillin component) divided every 12 hours or 20–40 mg/kg/day divided every 8 hours, not exceeding the usual adult maximum dose.

How and when to take it: Take each dose at the start of a meal with a full glass of water to improve absorption of the clavulanate component and reduce stomach upset; swallow tablets whole without crushing unless they are scored and your prescriber says splitting is acceptable, and measure the oral suspension with an oral syringe or dosing cup after shaking the bottle well.

Special instructions, missed doses, and overdose: Doses should be spaced as evenly as possible (for example every 8 or 12 hours) and the full prescribed course should be completed even if you feel better; if you miss a dose, take it as soon as you remember unless it is almost time for the next dose, in which case skip the missed dose and resume your regular schedule without doubling up; in suspected overdose (such as large accidental ingestion or symptoms like severe vomiting or diarrhea, confusion, or seizures), seek urgent medical care or contact a poison control center, where treatment is usually supportive and hemodialysis can be used in severe cases to help remove the drug.

Common side effects:

• Gastrointestinal upset (diarrhea, nausea, vomiting, abdominal discomfort) is the most frequent effect, usually mild to moderate, starting within the first few days of treatment and more common than with amoxicillin alone because of the clavulanate component.
• Other possible effects include headache, dizziness, mild skin rash, vaginal yeast infection, and oral thrush due to disruption of normal flora.

Serious or rare adverse effects (seek immediate care):

• Severe allergic reactions such as hives, wheezing, swelling of the face, lips, tongue, or throat, or trouble breathing, especially in people with prior penicillin or cephalosporin allergy.
• Severe skin reactions with blistering, peeling, or sores on the mouth, eyes, or genitals.
• Persistent, severe, or bloody diarrhea with stomach cramps or fever that may signal Clostridioides difficile–associated colitis.
• Signs of liver injury such as yellowing of the skin or eyes, dark urine, pale stools, severe fatigue, or right-upper-abdominal pain, which can appear during therapy or several weeks after stopping.
• Unusual bruising or bleeding, extreme tiredness, frequent infections suggesting blood cell changes, or seizures, especially with very high doses or severe kidney impairment.

Warnings and precautions: This medicine must not be used by anyone with a history of serious hypersensitivity to amoxicillin, clavulanate, other penicillins, or a prior episode of cholestatic jaundice or hepatitis caused by this drug; dose reductions and extended intervals are needed in significant kidney dysfunction, and careful monitoring is advised in liver disease; it is generally considered acceptable during pregnancy and breastfeeding when clearly needed, but use should be individualized and breastfed infants watched for diarrhea, rash, or thrush.

Relative safety profile: Amoxicillin and clavulanate is widely used and overall well tolerated, but causes more diarrhea and has a higher risk of liver enzyme elevations or cholestatic jaundice than amoxicillin alone, while lacking some of the tendon, nerve, and serious blood sugar risks associated with fluoroquinolone antibiotics.

Safety updates and reporting: Suspected side effects can be reported in the United States to the FDA MedWatch program (online or at 1-800-FDA-1088), and updated safety communications are available on the FDA’s Drug Safety web pages.

Drug interactions: Important interactions include probenecid (which raises and prolongs amoxicillin blood levels), oral anticoagulants such as warfarin and some direct oral anticoagulants (which may increase bleeding risk and warrant closer INR or clinical monitoring), allopurinol (which increases the risk of rash), methotrexate (reduced renal clearance and higher methotrexate levels with risk of toxicity), and other broad-spectrum antibiotics or drugs that significantly alter gut flora; like other penicillins, it may theoretically reduce the effectiveness of combined estrogen–progestin oral contraceptive pills, so backup contraception is sometimes recommended.

Interactions with OTC medicines, supplements, food, alcohol, and tests: Most over-the-counter pain relievers and cold medicines do not directly interact, but all new prescription, OTC, and herbal products should be checked with a clinician or pharmacist; doses should be taken with food, and there are no specific food restrictions, while moderate alcohol use is not strictly contraindicated but should be limited because alcohol can worsen stomach upset and, together with this medicine, may increase stress on the liver; the drug can interfere with some older urine glucose tests that use copper-reduction methods, so enzymatic tests are preferred.

Conditions and co-medications requiring caution: Extra caution is needed in people with a history of penicillin or cephalosporin allergy, prior antibiotic-associated colitis, moderate to severe kidney impairment, existing liver disease or previous Augmentin-related hepatitis, and in those taking other hepatotoxic drugs, anticoagulants, or medicines that suppress the bone marrow.

Monitoring needs: For short, standard courses in otherwise healthy patients, routine laboratory monitoring is usually unnecessary, but in longer courses or in patients with kidney, liver, or hematologic problems, clinicians often monitor renal function, liver enzymes, and complete blood counts, and may follow coagulation tests when the drug is combined with anticoagulants.

Q: How long does it take for amoxicillin and clavulanate to start working?
A: Many people begin to notice some improvement within 2 to 3 days, but you should keep taking it for the full prescribed course even if symptoms improve sooner.

Q: Can I drink alcohol while taking this antibiotic?
A: There is no strict ban on alcohol, but it is best to avoid or limit drinking because alcohol can worsen stomach upset and, together with this medicine, may put extra strain on the liver.

Q: What should I do if I develop diarrhea on this medication?
A: Mild loose stools are common and often improve if you take doses with food, but if diarrhea is severe, watery, bloody, or lasts more than a couple of days, contact your clinician promptly because it could indicate a more serious intestinal infection such as C. difficile colitis.

Q: Is amoxicillin and clavulanate safe during pregnancy and breastfeeding?
A: This medicine is generally considered acceptable in pregnancy and while breastfeeding when clearly needed, but the decision should be made with your obstetric or pediatric provider, and breastfed infants should be watched for diarrhea, rash, or thrush.

Q: What happens if I stop taking the antibiotic early because I feel better?
A: Stopping early can allow some bacteria to survive, which may cause the infection to return and can contribute to antibiotic resistance, so you should not stop or change the dose unless your clinician advises it.