What are the dosages of Monocef (ceftriaxone) and Amoxiclav (amoxicillin/clavulanic acid) for adults and children?

Dosages of Monocef (Ceftriaxone) and Amoxiclav (Amoxicillin/Clavulanic Acid) for Adults and Children

For optimal clinical outcomes, ceftriaxone (Monocef) should be dosed at 1-2 grams IV/IM once daily for adults and 50-100 mg/kg/day for children, while amoxicillin/clavulanic acid (Amoxiclav) should be dosed at 875/125 mg twice daily for adults and 40-90 mg/kg/day (of amoxicillin component) divided into 2-3 doses for children.

Ceftriaxone (Monocef) Dosing

Adult Dosing

• Standard dose: 1-2 grams IV/IM once daily 1
• Maximum dose: 4 grams per day 2
• Duration: Generally 4-14 days, continue for at least 2 days after signs and symptoms of infection have disappeared 2

Pediatric Dosing

• Standard infections: 50-75 mg/kg/day IV/IM once daily or divided twice daily 2
• Maximum dose: 2 grams per day for standard infections 2
• Severe infections/meningitis: 100 mg/kg/day (not to exceed 4 grams daily) 2
• Specific indications:
  • Acute otitis media: Single IM dose of 50 mg/kg (not to exceed 1 gram) 3, 4
  • Skin and soft tissue infections: 50-75 mg/kg/day once daily or divided twice daily 2, 5

Special Considerations

• Neonates: Contraindicated in premature neonates; in term neonates, administer IV doses over 60 minutes to reduce risk of bilirubin encephalopathy 2
• Renal/Hepatic impairment: No dosage adjustment necessary unless severe impairment 2
• Elderly: No modification required up to 2 grams per day in absence of severe renal/hepatic impairment 2

Amoxicillin/Clavulanic Acid (Amoxiclav) Dosing

Adult Dosing

• Standard formulation: 500/125 mg orally three times daily
• Extended-release formulation: 875/125 mg orally twice daily
• Maximum daily dose: 4000 mg amoxicillin component

Pediatric Dosing

• Standard infections: 40 mg/kg/day of amoxicillin component divided into 2-3 doses 3
• Severe infections: 90 mg/kg/day of amoxicillin component divided into 2-3 doses
• Specific indications:
  • Acute otitis media: 80 mg/kg/day of amoxicillin component with 10 mg/kg/day of clavulanate in three divided doses 4

Administration Guidelines

Ceftriaxone (Monocef)

• IV administration: Infuse over 30 minutes (60 minutes in neonates) 2
• IM administration: Inject well within a large muscle; reconstitute with appropriate diluent 2
• Compatibility: Do not use diluents containing calcium; compatible with metronidazole 2

Amoxicillin/Clavulanic Acid (Amoxiclav)

• Administer with food to enhance absorption and reduce GI side effects
• Extended-release tablets should be swallowed whole, not crushed or chewed

Clinical Pearls and Pitfalls

1. Pharmacokinetic advantages of ceftriaxone: Long half-life (7-8 hours) allows once-daily dosing in adults and children, providing sustained plasma concentrations above MICs for most pathogens for 24 hours 6, 7

2. Common pitfalls to avoid:

   • Do not administer ceftriaxone with calcium-containing solutions, especially in neonates 2
   • Do not use amoxicillin/clavulanic acid in patients with history of penicillin allergy
   • Avoid underdosing amoxicillin/clavulanic acid in areas with high prevalence of resistant organisms

3. Efficacy considerations:

   • Ceftriaxone 2g once daily is as effective as more frequent dosing regimens of other cephalosporins for serious bacterial infections 8
   • Single-dose ceftriaxone (50 mg/kg) has comparable efficacy to 10-day amoxicillin/clavulanic acid for pediatric acute otitis media 4

Always consider local antimicrobial resistance patterns and adjust therapy accordingly. Monitor for clinical improvement within 48-72 hours and consider de-escalation to oral therapy when appropriate.