Introduction

Name

• Amoxycillin.

Class of drug

• Penicillin antibiotic.

Description

Chemical name

• 6[D(-)-a-amino-p-hydroxyphenylacetamido]penicillanic acid.

Molecular formula

• C16H19N3O5S.
• Similar to ampicillin, but with an extra hydroxyl group on the phenyl ring.

Molecular weight

• 419.45 g.

Physical properties

• Tablets (50 mg, 250 mg, 500 mg).
• Powder for oral solutions (50% w/w equivalent to 500 mg/g and 100% w/w equivalent to 1000 mg/g).
• Powder is usually white and odorless.
• Acid-stable, beta-lactamase-susceptible.
• Various injectable formulations typically containing a non-aqueous or oily suspension of amoxicillin trihydrate at a concentration of 150 mg/ml.
• Sparingly soluble in water, lipid insoluble.

Storage requirements

• <25°C.
• In a dry environment.
• Self-life and manufacturer's recommendations should be respected.

Uses

Indications

• Actrive against certain gram-positive and negative organisms.
• Generally indicated for the treatment of skin diseases, soft tissue infections, dental infections, urinary tract infections and respiratory disease in small animals (dogs and cats).
• Not active against those that produce penicillinases, egE. coli  Escherichia coli   andStaphylococcus aureus  Staphylococcus aureus  .
• The more difficult gram-negative organisms, egPseudomonasspp   Pseudomonads  , are usually resistant.

Administration

Pharmacokinetics

Precautions

Interactions

with other drugs

• Probenecid: will decrease the renal tubular secretion of penicillin   Penicillin  antibiotics and thus prolong their blood levels.
• Aminoglycosides: do not mix in the same syringe as aminoglycosides.

Not recommended for use with bacteriostatic antibiotics.

with diagnostic tests

• Little information available.

Adverse Reactions

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Kelley Fann M & O'Rourke D (2001) Normal bacterial flora of the rabbit gastrointestinal tract: A clinical approach. Semin Avian Exotic Pet Med 10 (1), 45-47 ResearchGate.
• Woodnut G, Berry V & Mizen L (1995) Effect of protein binding on penetration of beta-lactams into rabbit peripheral lymph. Antimicrob Agents Chemother 39 (12), 2678-2683 PubMed.
• Hillyer E V (1994) Pet rabbits. Vet Clin North Am: Small Anim Pract 24, 25-65 PubMed.
• Lashev L (1986) [Comparative pharmacokinetic research in agricultural animals.] Vet Med Nauki 23 (10), 76-82 PubMed.
• Pujadas R, Escriva E, Jane J et al (1986) Comparative capacity of orally administered amoxicillin and parenterally administered penicillin-streptomycin to protect rabbits against experimentally induced streptococcal endocarditis. Antimicrob Agents Chemother 29 (5), 909-912 PubMed.
• Uematsu M, Ito T, Morishima T et al (1983) [Study on distribution to oral tissues of long acting amoxicillin.] Jap J Antibiot 36 (2), 423-427 PubMed. 
• Faiqenbaum S J, Boyle G L, Prywes A S et al (1976) Intraocular penetrating of amoxicillin. Am Ophthalmol 82 (4), 598-603 PubMed.

Other sources of information

• Ramsey I (2011) Ed Small Animal Formulary. 7th edn. Cheltenham: BSAVA.
• Carpenter J W (2005) Exotic animal formulary. 3rd edn. St Louis: Elsevier Publishing