Ampicillin and Sulbactam
Also known as: Unasyn
* **Hospital Use Only**: Because this medication must be given by injection (IV or IM) and requires frequent dosing (every 6 to 8 hours), it is best administered to hospitalized patients. * **Purpose**: It is a potent antibiotic combination used to treat severe or resistant bacterial infections, often utilized when oral medications cannot be tolerated. * **Safety**: Generally very safe, but let your veterinary team know if your pet has ever had an allergic reaction to penicillin-type drugs.
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
- For respiratory infections using ampicillin/sulbactam (Unasyn®)
- As adjunctive treatment of serious bite wounds
- For intra-abdominal infections
- For respiratory infections
- For respiratory infections
- As adjunctive treatment of serious bite wounds
- For intra-abdominal infections
How it is given
Possible side effects
- Pain at intramuscular injection sites
- Thrombophlebitis (with intravenous injection)
- Hypersensitivity reactions (including severe anaphylaxis, particularly after IV administration)
- Neurotoxicity (e.g., ataxia in dogs) at high doses or prolonged use
- Elevated liver enzymes
- Tachypnea, dyspnea, edema, and tachycardia (reported in dogs)
Cautions & contraindications
- Patients with a history of severe hypersensitivity (e.g., anaphylaxis) to penicillins
- Use cautiously in patients with documented hypersensitivity to other beta-lactam antibiotics (e.g., cephalosporins, cefamycins, carbapenems) due to potential cross-reactivity. Patients with severe renal dysfunction may require increased intervals between doses. Safe use during pregnancy has not been firmly established (FDA Category B; Papich Class A), use only when potential benefits outweigh risks.
Drug interactions
- Aminoglycosides (amikacin, gentamicin, tobramycin): In vitro inactivation if mixed together; synergistic in vivo, but penicillins can inactivate aminoglycosides in patients with renal failure or when used in massive dosages. Amikacin is the most resistant to this inactivation.
- Bacteriostatic antimicrobials (chloramphenicol, macrolides, tetracyclines, sulfonamides): Potential in vitro antagonism between beta-lactam antibiotics and bacteriostatic antibiotics; clinical importance is unclear.
- Probenecid: Reduces the renal tubular secretion of both ampicillin and sulbactam, maintaining higher systemic levels for a longer period.
Frequently asked questions
What is Ampicillin and Sulbactam used for in pets?
* **Hospital Use Only**: Because this medication must be given by injection (IV or IM) and requires frequent dosing (every 6 to 8 hours), it is best administered to hospitalized patients. * **Purpose**: It is a potent antibiotic combination used to treat severe or resistant bacterial infections, often utilized when oral medications cannot be tolerated. * **Safety**: Generally very safe, but let your veterinary team know if your pet has ever had an allergic reaction to penicillin-type drugs.
Is Ampicillin and Sulbactam 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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