Amoxicillin/Clavulanate: Dosage, Uses, and Side Effects

Amoxicillin/Clavulanate for Dogs, Cats, and Different Animal Species: Dosage, Uses, and Side Effects Guide

Overview

• Amoxicillin binds to penicillin-binding proteins that are involved in bacterial cell walls.
• This makes the cell walls weaker and less rigid, which affects cell division, growth, and the formation of cell walls.
• Clavulanate and the beta-lactamase inhibitor broaden the antimicrobial spectrum against Staphylococcus and E. coli.

Uses of Co-amoxiclav (Amoxicillin/Clavulanate)

• Effective against Gram-positive and Gram-negative aerobic bacteria and many obligate anaerobes.
• Active against beta-lactamase-producing Escherichia coli, Staphylococcus spp., and Pasteurella multocida.
• Ineffective against difficult Gram-negative organisms like Pseudomonas aeruginosa, Serratia spp., and Klebsiella spp..
• Commonly used for:
  • Skin and soft tissue infections (e.g., wounds, abscesses).
  • Urinary tract infections (UTIs).
  • Respiratory infections.
  • Canine periodontal disease.
  • Surgical prophylaxis.

Dose of Amoxicillin/Clavulanate

Dose of Amoxicillin/Clavulanate In Dogs and Cats:

• Parenteral:
  • Standard dose: 8.75–25 mg/kg (combined) i.v. q8h; i.m. or s.c. q24h.
  • Surgical prophylaxis: 22–25 mg/kg i.v. 30 minutes prior to surgery, then q1.5–2h during surgery.
• Oral:
  • Standard dose: 12.5–25 mg/kg (combined) p.o. q8–12h.

Dose of Amoxicillin/Clavulanate In Birds:

• Susceptible infections (extra-label):
  • 50–100 mg/kg p.o. q6–8h.

Dose of Amoxicillin/Clavulanate In Ferrets:

• Susceptible infections (extra-label):
  • 10–20 mg/kg p.o. q8–12h.

Dose of Amoxicillin/Clavulanate In Reptiles:

• Susceptible infections (extra-label):
  • 22 mg/kg p.o. q12–24h.

Dose of Amoxicillin/Clavulanate In Cattle:

• Parenteral: 8.75–25 mg/kg i.m. or s.c. q24h.
  • Note: Verify withdrawal periods for milk and meat with regulatory agencies.

Dose of Amoxicillin/Clavulanate In Small Mammals (e.g., Rabbits, Guinea Pigs, Hamsters):

• Contraindicated: Oral administration can lead to fatal enteritis due to disruption of GI flora.

Side Effects of Amoxicillin/Clavulanate

• Common:
  • Nausea, vomiting, diarrhea.
  • Skin irritation or rash.
• Less Common but Serious:
  • Allergic reactions: edema, pruritis, urticaria (hives), and hypotension.
  • GI upset may increase when used with general anesthesia for surgical prophylaxis.

Contraindications of Amoxicillin/Clavulanate

• Known hypersensitivity to penicillins or other beta-lactam antibiotics (e.g., cephalosporins).
• Critically ill patients where GI absorption is unreliable; use i.v. antibiotics instead.
• Avoid use in small mammals (e.g., rabbits, guinea pigs, hamsters) due to the risk of life-threatening enteritis.

Some Notes:

• Resistance:
  • Resistance may occur due to bacterial production of extended-spectrum beta-lactamases (ESBLs) in Klebsiella spp. and Pseudomonas spp..
  • For empirical therapy of UTIs, amoxicillin (without clavulanate) is often preferred due to its high urinary concentration.
• Drug Interactions:
  • Avoid concurrent use with bacteriostatic antibiotics (e.g., tetracyclines, macrolides) due to potential antagonistic effects.
  • Do not mix with aminoglycosides in the same syringe; however, concurrent administration may result in synergism.
• Administration Tips:
  • Oral formulations can be given with or without food, but administering with food may reduce GI side effects.
  • Refrigerate oral suspension after reconstitution and discard after 10 days.
• Monitoring:
  • Monitor for clinical resolution of infection and adverse effects.
  • Consider culture and susceptibility testing for recurrent or unresolved infections.