Co-amoxiclav is a broad-spectrum, combination antibiotic formulated to effectively treat a wide range of bacterial infections. It merges the bactericidal action of amoxicillin, a penicillin-type antibiotic, with clavulanic acid, a beta-lactamase inhibitor that prevents bacterial resistance. This synergistic approach enhances its efficacy against both gram-positive and gram-negative pathogens, making it a first-line choice for complicated and recurrent infections. Prescribed globally, it is available under various brand names and is indicated for respiratory, urinary, skin, and soft tissue infections, among others.

Features

• Contains amoxicillin and clavulanic acid in a fixed combination ratio
• Available in multiple formulations: tablets, chewable tablets, oral suspension, and intravenous injection
• Standard strengths include 250/125 mg, 500/125 mg, and 875/125 mg (amoxicillin/clavulanic acid)
• Exhibits time-dependent bactericidal activity
• Stable across a range of pH conditions in the gastrointestinal tract
• Requires prescription in most jurisdictions

Benefits

• Effectively eradicates beta-lactamase-producing bacteria that are resistant to amoxicillin alone
• Broad spectrum of activity covers common pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, E. coli, and Staphylococcus aureus
• Rapid onset of action with symptomatic improvement often within 48–72 hours
• Flexible dosing regimens adaptable to infection severity and patient demographics
• Well-established safety profile with extensive clinical use over decades
• Reduces the need for broader-spectrum or more toxic antibiotics in many cases

Common use

Co-amoxiclav is indicated for the treatment of bacterial infections caused by susceptible organisms. Common uses include:

• Acute bacterial sinusitis
• Community-acquired pneumonia
• Acute otitis media
• Urinary tract infections (including pyelonephritis)
• Skin and soft tissue infections (e.g., cellulitis, abscesses)
• Dental infections
• Bone and joint infections
• Intra-abdominal infections
• Prophylaxis in surgical procedures

Dosage and direction

Dosage varies based on infection severity, patient age, renal function, and formulation. General adult dosing for mild to moderate infections is one 500/125 mg tablet every 12 hours, or one 250/125 mg tablet every 8 hours. For severe infections, one 875/125 mg tablet every 12 hours is recommended. Pediatric dosing is weight-based, typically 25–45 mg/kg/day (amoxicillin component) divided every 8 or 12 hours. Oral suspension should be shaken well before use. Tablets may be taken with food to minimize gastrointestinal upset. Complete the full course even if symptoms improve earlier.

Precautions

• Use with caution in patients with hepatic impairment; monitor liver function periodically
• Assess renal function before and during therapy; adjust dose in renal impairment (e.g., CrCl <30 mL/min)
• May cause false-positive glucose reactions with copper reduction tests (e.g., Clinitest®)
• Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea
• Not recommended during pregnancy unless clearly needed; use during lactation may lead to sensitization in the infant
• Ensure adequate hydration to reduce risk of crystalluria

Contraindications

• History of hypersensitivity to penicillins, cephalosporins, or other beta-lactam antibiotics
• Previous history of co-amoxiclav-associated jaundice or hepatic dysfunction
• Infectious mononucleosis (due to high risk of rash)
• Severe renal impairment without appropriate dose adjustment

Possible side effect

Common side effects (≥1/100) include:

• Diarrhea, nausea, vomiting
• Skin rash, urticaria
• Vaginal candidiasis

Uncommon side effects (≥1/1000 to <1/100) include:

• Headache, dizziness
• Reversible leukopenia, thrombocytopenia
• Elevated liver enzymes

Rare but serious side effects (<1/1000) include:

• Anaphylaxis, angioedema
• Stevens-Johnson syndrome, toxic epidermal necrolysis
• Hepatitis, cholestatic jaundice
• Clostridium difficile-associated colitis
• Interstitial nephritis

Drug interaction

• Probenecid reduces renal excretion of amoxicillin, increasing its serum concentration
• Concurrent use with allopurinol may increase incidence of skin rash
• May reduce efficacy of oral contraceptives; advise alternative contraception during treatment
• May potentiate anticoagulant effect of warfarin; monitor INR
• Bacteriostatic antibiotics (e.g., tetracyclines, macrolides) may interfere with bactericidal action

Missed dose

If a dose is missed, take it as soon as remembered unless it is almost time for the next dose. Do not double the dose to catch up. Resume the regular dosing schedule. Consistent dosing is important to maintain effective antibiotic concentrations.

Overdose

Symptoms may include gastrointestinal disturbances (nausea, vomiting, diarrhea), electrolyte imbalances, and crystalline. Management is supportive; maintain hydration and electrolyte balance. Hemodialysis may remove both amoxicillin and clavulanic acid. There is no specific antidote.

Storage

Store tablets and powder for oral suspension at room temperature (15–30°C). Keep in original container, tightly closed. Reconstituted oral suspension is stable for 7–10 days under refrigeration (2–8°C); do not freeze. Keep out of reach of children.

Disclaimer

This information is for educational purposes only and does not replace professional medical advice. Always consult a healthcare provider for diagnosis, treatment decisions, and personalized dosing. Do not self-medicate or share antibiotics with others.

Reviews

Co-amoxiclav is widely regarded in clinical practice for its reliability and broad-spectrum efficacy. Systematic reviews and meta-analyses support its use for respiratory and urinary tract infections, noting high clinical cure rates. Some criticisms include gastrointestinal side effects and the need for multiple daily dosing in certain formulations. Overall, it remains a cornerstone in empirical antibiotic therapy where beta-lactamase-producing bacteria are suspected.