Amoxicillin
Antibiotic
View Brand Names (24)Dose and dosage
For susceptible infections:
a) For Gram-positive infections: 10 mg/kg PO, IM, SC twice daily for at least 2 days after symptoms subside.
For Gram-negative infections: 20 mg/kg PO three times daily or IM, SC twice daily for at least 2 days after symptoms subside.
b) For susceptible UTI’s: 10–20 mg/kg PO q12h for 5–7 days.
For susceptible systemic infections (bacteremia/sepsis): 22–30 mg/kg IV, IM, SC q8h for 7 days.
For susceptible orthopedic infections: 22–30 mg/kg IV, IM, SC, or PO q6–8h for 7–10 days.
c) For Lyme disease: 22 mg/kg PO q12h for 21–28 days.
d) For susceptible urinary tract infections: 11 mg/kg PO q8h. For preventative therapy for repeated (>2 per 6 months) urinary tract Grampositive bacterial infections: 20 mg/kg PO once daily before bedtime after the dog has urinated. Use only after effective treatment completed using full therapeutic doses.
For susceptible infections:
a) For Gram-positive infections: 10 mg/kg PO, IM, SC twice daily for at least 2 days after symptoms subside.
For Gram-negative infections: 20 mg/kg PO three times daily or IM,
SC twice daily for at least 2 days after symptoms subside
b) For susceptible UTI’s and soft tissue infections: 50 mg (total dose per
cat) or 11–22 mg/kg PO once daily for 5–7 days.
For sepsis: 10–20 mg/kg IV, SC, or PO q12h for as long as necessary. Note: Duration of treatment are general guidelines, generally treat for at least 2 days after all signs of infection are gone.
c) C. perfringens, bacterial overgrowth (GI): 22 mg/kg PO once daily for 5 days
d) C. perfringens enterotoxicosis: 11–22 mg/kg PO two to three times daily for 7 days
e) For treating H. pylori infections using triple therapy: amoxicillin 20 mg/kg PO twice daily for 14 days; metronidazole 10–15 mg/kg PO twice daily; clarithromycin 7.5 mg/kg PO twice daily
For susceptible infections:
a) 6–10 mg/kg SC or IM q24h (Withdrawal time = 30 days)
b) For respiratory infections: 11 mg/kg IM or SC q12h
c) Calves: Amoxicillin trihydrate: 7 mg/kg PO q8–12h
In calf: 10-22 mg/kg q8-12h PO
For susceptible infections:
a) For respiratory infections: 20–30 mg/kg PO q6h (Beech 1987a)
b) Foals: Amoxicillin Sodium: 15–30 mg/kg IV or IM q6–8h; amoxicillin
trihydrate suspension: 25–40 mg/kg PO q8h; amoxicillin/clavulanate 15–
25 mg/kg IV q6–8h
For eliminating Helicobacter gastritis infections:
a) Using triple therapy: Metronidazole 22 mg/kg, amoxicillin 22 mg/kg and bismuth subsalicylate (original Pepto-Bismol®) 17.6 mg/kg PO. Give each 3 times daily for 3–4 weeks.
b) Using triple therapy: Metronidazole 20 mg/kg PO q12h, amoxicillin 20
mg/kg PO q12h and bismuth subsalicylate 17.5 mg/kg PO q8h. Give 21
days. Sucralfate (25 mg/kg PO q8h) and famotidine (0.5 mg/kg PO once
daily) are also used. Fluids and assisted feeding should be continued
while the primary cause of disease is investigated.
For susceptible infections:
a) 125 mg/kg q12h PO. Mix oral solution to double strength to a final concentration of 125 mg/mL.
b) 100 mg/kg q8h, IM, SC, PO
c) Ratites: 15–22 mg/kg PO twice daily; in drinking water: 250 mg/gallon for 3–5 days
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Urinary and Reproductive System: Mastitis, Metritis, Pyometra, Retention of Placenta, Cystitis, Nephritis, Metritis-Mastitis-Agalactia (MMA) Syndrome.
Respiratory System: Pneumonia, Bronchitis, Calf Diphtheria, Sinusitis, Pharyngitis, Laryngitis
Digestive System: Calf Scour, Salmonellosis, Gastritis, Enteritis, Stomatitis, Campylobacteriosis
Musculo-skeletal System: Skin and Soft tissue infection, Abscess, Wound, Black quarter, Arthritis, Eczema
Prevention of Secondary bacterial Infection.
Beta-lactam antibiotic. Amoxicillin inhibits bacterial cell wall synthesis. Amoxicillin generally has a narrow spectrum of activity that includes streptococci, non–beta-lactamase–
producing staphylococci, and other gram-positive cocci and bacilli.
Many Staphylococcus strains are resistant because of beta-lactamase production. Most enteric gram-negative Enterobacteriaceae bacilli are resistant. Susceptible gram-negative bacteria include some species of Proteus, Pasteurella multocida, and Histophilus spp. resistance among other gram-negative bacteria is common.
BACTERIOSTATIC ANTIMICROBIALS (e.g., chloramphenicol, erythromycin and other macrolides, tetracyclines, sulfonamides, etc.): Because there is evidence of in vitro antagonism between beta-lactam antibiotics and bacteriostatic antibiotics, use together has been generally not recommended in the past, but actual clinical importance is not clear and in doubt.
METHOTREXATE: Amoxicillin may decrease the renal excretion of MTX causing increased levels and potential toxic effects.
PROBENECID: Competitively blocks the tubular secretion of most penicillins, thereby increasing serum levels and serum half-lives.
Adverse effects with the penicillins are usually not serious and have a relatively low frequency of occurrence. Hypersensitivity reactions unrelated to dose can occur with these agents and can manifest as rashes, fever, eosinophilia, neutropenia, agranulocytosis, thrombocytopenia, leukopenia, anemias, lymphadenopathy, or full blown anaphylaxis.
When given orally, penicillins may cause GI effects (anorexia, vomiting, diarrhea). Because the penicillins may alter gut flora, antibiotic-associated diarrhea can occur and allow the proliferation of resistant bacteria in the colon (superinfections). Healthy dogs given oral amoxicillin had their gut flora altered with a shift in balance toward gram-negative bacteria that included resistant Enterobacteriaceae species
High doses or very prolonged use have been associated with neurotoxicity (e.g., ataxia in dogs). Although the penicillins are not considered hepatotoxic, elevated liver enzymes have been reported. Other effects reported in dogs include tachypnea, dyspnea, edema and tachycardia.
Penicillins have been shown to cross the placenta; safe use during pregnancy has not been firmly established, but neither have there been any documented teratogenic problems associated with these drugs. However, use only when the potential benefits outweigh the risks. In humans, the FDA categorizes this drug as category B for use during pregnancy.
25 days for meat, 96 hours for milk. Amoxicillin intramammary infusion: withdrawal time 12 days for meat, 60 hours for milk