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Combination Drug:
Amoxicillin Trihydrate/Clavulanate Potassium , Amoxicillin Trihydrate/Clavulanic Acid

Brands

Clavamox, Augmentin, Synulox

Availability

Suspension available in: 62.5 mg & 125 mg
Tablets: 250 mg

Pharmacology

Amoxicillin, an aminopencillin beta-lactam, differs structurally from ampicillin by having an addition hydroxyl group on the phenyl ring. It is a bactericidal broad-spectrum antibiotic.

When Clavulanate Potassium and Clavulanic Acid (beta-lactamase inhibitors) are used in combined form with the penicillins, such as amoxicillin, they prevent hydrolyzed penicillins, like amoxicillin, from being inactivated by bacterial beta-lactamases.
The antibacterial activity of Clavulanate Potassium and Clavulanic Acid is weak when used alone, and is therefore only available in combination form.

Studies have shown that amoxicillin/clavulanate has a wide range of activity against β-lactamase-producing strains of both Gram-positive and Gram-negative aerobes, facultative anaerobes, and obligate anaerobes.

Amoxicillin and clavulanic acid are both readily distributed into most body tissues and fluids. Note that low concentrations of the drugs are found in saliva, sputum and uninflamed meninges while high concentrations are found in inflamed meninges. Both amoxicillin and clavulanic acid readily cross the placenta and are found in breast milk in low concentrations. Most of the amoxicillin is excreted unchanged in the urine. Excreted levels of clavulanic acid is reported to be only 1/5th that of amoxicillin.

Indications

Used to treat:

• Lower Respiratory Tract Infections - caused by S. pneumoniae and M. catarrhalis.
• Otitis Media - caused by S. pneumoniae and M. catarrhalis.
• Skin and Skin Structure Infections - caused by β-lactamase-producing strains of S. aureus, E. coli, and Klebsiella spp.
• Urinary Tract Infections - caused by β-lactamase-producing strains of E. coli, Klebsiella spp. and Enterobacter spp.

Clinical Note

Although amoxicillin/clavulanate is commonly used against infections caused by S. pneumoniae, it should be noted that the organism Streptococcus does not produce beta-lactamase. If the organism, Streptococcus, is identified on culture, an alternative choice would be to use azithromycin, or to combine the beta-lactamase inhibitor, amoxicillin-clavulanate, with azithromycin.

Drug Interactions or Contraindications

Concomitant use of Probenecid will increase the plasma level of this antibiotic.

Adverse Reactions

Blood:  anemias

GI:  anorexia,diarrhea

Other:  hypersensitivity reaction such as rash and itching.Prolonged high doses can cause neurotoxicity.When given orally the penicillins may alter gut flora,selecting out resistant bacteria residing in the colon(leading to superinfections).

Dosage Recommendations

Caution: Loose stool/diarrhea not an uncommon side effect of this antibiotic. Use higher doses judiciously where condition warrants. In the event loose stools/diarrhea can not be controlled with probiotics contact veterinarian immediately to reduce antibiotic dose, stopping antibiotic, or switching to another antimicrobial to prevent complication of enterocolitis.

6.25 mg/lb, PO, BID  ⁴
Given over 10-14 days.

or

20 mg/kg, PO, q12hrs  ³⁴

or

30 mg/kg to 40mg/kg, PO, q12hrs  ²¹. Dosage range used successfully in pet rats by Vanessa Pisano DVM.

or

100 mg/kg, PO, q12hrs  ²⁹. *Note: use cautiously*

Considerations

• May give with food,does not significantly reduce absorption of drug.
• Give yogurt, Lactobacillus capsules/granules, or Bene-Bac to help maintain normal gut flora.
• Can be used simultaneously with Gentocin or Amikacin, or Baytril (enrofloxacin), or azithromycin.
• For oral suspension shake well, refrigerate, and discard any unused portion after 10 days.

Posted on June 23, 2003, 14:36, Last updated on May 16, 2012, 15:29 | Antimicrobial Agents