Amoxicillin
Also known as: Amoxil, Amoxi-Tabs, Amoxi-Drop, Amoxi-Mast, Trimox, Moxatag, Amoxibactin, Amoxycare, Amoxypen, Betamox, Bimoxyl, Clamoxyl
* **Administration**: Amoxicillin can be given with or without food. However, if your pet experiences stomach upset (vomiting or loss of appetite), giving the medication with a meal may help. * **Storage**: If you are using the liquid oral suspension, it is best to keep it refrigerated, though room temperature is acceptable. **Discard any unused liquid after 14 days**. * **Completion of Therapy**: Always finish the entire prescription as directed by your veterinarian, even if your pet seems completely better. Stopping early can lead to resistant bacterial infections. * **Side Effects**: Mild diarrhea or vomiting can occur. If these symptoms become severe, or if you notice signs of an allergic reaction (like facial swelling, hives, or difficulty breathing), contact your veterinarian immediately. * **Species Warning**: Never share this medication with small pets like rabbits, guinea pigs, or hamsters, as it can be fatal to them.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Gram-positive infections
- Gram-negative infections
- Susceptible UTI's
- Susceptible systemic infections (bacteremia/sepsis)
- Susceptible orthopedic infections
- Lyme disease
- Susceptible urinary tract infections
- Preventative therapy for repeated (>2 per 6 months) urinary tract Gram-positive bacterial infections
- Susceptible bacterial infections
- Susceptible bacterial infections (depot preparations)
- Susceptible bacterial infections
- Bacterial cystitis
- Susceptible infections
How it is given
Possible side effects
- Gastrointestinal upset (anorexia, vomiting, diarrhea)
- Antibiotic-associated diarrhea and gut flora alteration
- Hypersensitivity reactions (rashes, fever, anaphylaxis)
- Eosinophilia, neutropenia, agranulocytosis, thrombocytopenia, leukopenia, anemias
- Lymphadenopathy
- Neurotoxicity (e.g., ataxia) at very high doses or prolonged use
- Elevated liver enzymes (rare)
- Tachypnea, dyspnea, edema, and tachycardia (reported in dogs)
Cautions & contraindications
- Patients with a history of hypersensitivity to penicillins
- Oral administration in hindgut fermenters (rabbits, guinea pigs, chinchillas, hamsters) due to risk of fatal clostridial enterotoxemia
- Oral administration in patients with septicemia, shock, or grave illness (due to delayed/diminished GI absorption)
- > **Species Warning**: Never administer amoxicillin (or other penicillins) orally to rabbits, guinea pigs, chinchillas, or hamsters, as it can cause severe, often fatal, clostridial enterotoxemia. * **Cross-Reactivity**: Use with caution in patients with documented hypersensitivity to other beta-lactam antibiotics (e.g., cephalosporins, carbapenems). * **Pregnancy**: Crosses the placenta. Categorized as FDA Category B (human) and Class A (veterinary - probably safe), but should be used only when potential benefits outweigh risks. * **Laboratory Tests**: May cause false-positive urine glucose determinations when using cupric sulfate solutions (e.g., Clinitest).
Drug interactions
- Bacteriostatic antimicrobials (e.g., chloramphenicol, macrolides, tetracyclines, sulfonamides): Potential in vitro antagonism; concurrent use has historically been discouraged, though clinical significance is debated.
- Methotrexate: Amoxicillin may decrease the renal excretion of methotrexate, leading to increased levels and potential toxicity.
- Probenecid: Competitively blocks the tubular secretion of penicillins, increasing serum levels and prolonging serum half-life.
- Aminoglycosides: In vitro inactivation of aminoglycosides by beta-lactams; may falsely decrease aminoglycoside serum concentrations if samples are stored prior to analysis.
- Tetracycline: Potential antagonism of bactericidal activity (bacteriostatic vs bactericidal)
- Erythromycin: Potential antagonism of bactericidal activity
- Chloramphenicol: Potential antagonism of bactericidal activity
- Aminoglycosides (in vitro): Inactivation of aminoglycoside if mixed in the same syringe
- Aminoglycosides (in vivo): Synergistic antimicrobial effect when used concurrently
Frequently asked questions
What is Amoxicillin used for in pets?
* **Administration**: Amoxicillin can be given with or without food. However, if your pet experiences stomach upset (vomiting or loss of appetite), giving the medication with a meal may help. * **Storage**: If you are using the liquid oral suspension, it is best to keep it refrigerated, though room temperature is acceptable. **Discard any unused liquid after 14 days**. * **Completion of Therapy**: Always finish the entire prescription as directed by your veterinarian, even if your pet seems completely better. Stopping early can lead to resistant bacterial infections. * **Side Effects**: Mild diarrhea or vomiting can occur. If these symptoms become severe, or if you notice signs of an allergic reaction (like facial swelling, hives, or difficulty breathing), contact your veterinarian immediately. * **Species Warning**: Never share this medication with small pets like rabbits, guinea pigs, or hamsters, as it can be fatal to them.
Is Amoxicillin safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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