AUGMENTIN '125'
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AUGMENTIN '125' (AUGMENTIN '125').
Amoxicillin inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), inhibiting transpeptidation and autolysin activation. Clavulanate is a beta-lactamase inhibitor that irreversibly binds to and inactivates beta-lactamases, preventing hydrolysis of amoxicillin.
| Metabolism | Amoxicillin is partially metabolized by hydrolysis to penicilloic acid; clavulanate is extensively metabolized by hydrolysis and conjugation, primarily by the liver. |
| Excretion | Amoxicillin: ~50-70% excreted unchanged in urine via glomerular filtration and tubular secretion; clavulanate: ~30-50% excreted unchanged in urine. Small amounts eliminated in bile and feces. |
| Half-life | Amoxicillin: 1.0-1.3 hours (prolonged in renal impairment; up to 7-20 hours in anuria). Clavulanate: 0.9-1.2 hours (increased in renal impairment). |
| Protein binding | Amoxicillin: ~17-20% bound to serum proteins (mainly albumin). Clavulanate: ~25-30% bound to albumin. |
| Volume of Distribution | Amoxicillin: 0.21-0.41 L/kg; distributes well into body fluids and tissues including lungs, sinuses, and middle ear. Clavulanate: 0.3-0.4 L/kg. |
| Bioavailability | Oral: Amoxicillin 74-92% (dose-dependent); clavulanate ~60-75% (enhanced by food). |
| Onset of Action | Oral: Peak serum concentrations reached in 1-2 hours; antibacterial effect begins within 1-2 hours. |
| Duration of Action | Bactericidal levels maintained for 6-8 hours; dosing interval is typically every 8 or 12 hours depending on formulation and indication. |
One AUGMENTIN '125' tablet (amoxicillin 125 mg, clavulanate 31.25 mg) orally every 8 hours for mild to moderate infections.
| Dosage form | TABLET, CHEWABLE |
| Renal impairment | CrCl 10-30 mL/min: one tablet every 12 hours; CrCl <10 mL/min: one tablet every 24 hours; hemodialysis: one tablet every 24 hours, plus one dose during and post-dialysis. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: use with caution, monitor; Child-Pugh Class C: contraindicated. |
| Pediatric use | For children weighing <40 kg: based on amoxicillin component, 20-40 mg/kg/day in divided doses every 8 hours; for children ≥40 kg: adult dosing. |
| Geriatric use | Monitor renal function; adjust dose based on creatinine clearance; use lower end of dosing interval in elderly with impaired renal function. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AUGMENTIN '125' (AUGMENTIN '125').
| Breastfeeding | Excreted in low levels in breast milk. M/P ratio: 0.004-0.03 for amoxicillin; clavulanate undetectable or negligible. Considered compatible with breastfeeding; monitor infant for diarrhea, rash, or candidiasis. |
| Teratogenic Risk | Animal studies show no teratogenicity. Human data: no increased risk of major malformations with first-trimester exposure. Risk of necrotizing enterocolitis in neonates if maternal ampicillin-resistant infections treated near delivery. |
| Fetal Monitoring |
■ FDA Black Box Warning
None
| Serious Effects |
History of allergic reaction to penicillins, cephalosporins, or other beta-lactams; History of cholestatic jaundice or hepatic dysfunction with Augmentin; Mononucleosis (amoxicillin component causes rash); Severe renal impairment (creatinine clearance <30 mL/min) requires dosage adjustment.
| Precautions | Hypersensitivity reactions (anaphylaxis, Stevens-Johnson syndrome); Clostridium difficile-associated diarrhea; Hepatotoxicity (elevated liver enzymes, cholestatic hepatitis); Use in mononucleosis (high risk of rash); Prolonged use may lead to superinfection. |
| Food/Dietary | Take with food or milk to minimize GI side effects. No significant food-drug interactions, but avoid alcohol consumption during treatment as it may exacerbate hepatotoxicity risk. |
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| Monitor maternal allergic reactions, GI adverse effects. No specific fetal monitoring required; observe neonate for jaundice if used near term (potential bilirubin displacement). |
| Fertility Effects | No evidence of adverse effects on fertility in animal or human studies. |
| Clinical Pearls | Augmentin '125' refers to an amoxicillin/clavulanate formulation with 125 mg clavulanic acid per dose, typically used for pediatric patients or reduced clavulanate dosing. Monitor for diarrhea due to clavulanate; consider probiotics. Adjust dose in renal impairment (CrCl <30 mL/min). Not first-line for sinusitis or otitis media due to increasing resistance. |
| Patient Advice | Take with food to reduce gastrointestinal upset. · Complete entire prescribed course even if symptoms improve. · Shake liquid suspension well before each dose; refrigerate and discard after 10 days. · Report severe diarrhea, rash, or signs of liver injury (jaundice, dark urine) immediately. · Do not skip doses: if a dose is missed, take it as soon as remembered unless near next dose; do not double. |