Ampicillin / Cloxacillin
Ampicillin/Cloxacillin is a combination antibiotic that merges two penicillin-class medications to provide broad-spectrum coverage against various bacterial infections. This fixed-dose combination is particularly effective against both penicillin-sensitive organisms and penicillinase-producing staphylococci, making it useful when the causative bacteria cannot be immediately identified. The combination allows for treatment of infections that might otherwise require multiple antibiotics.
A broad-spectrum penicillin combination antibiotic used to treat various bacterial infections, particularly those involving staphylococci and other gram-positive organisms.
Key facts at a glance
- RxNorm
- 106846
- Generic
- Ampicillin / Cloxacillin
- Class
- multi-ingredient
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Treats respiratory tract infections, skin and soft tissue infections, urinary tract infections, and other bacterial infections caused by susceptible organisms. Commonly prescribed when bacterial cause is uncertain or for mixed infections requiring broad coverage.
Both ampicillin and cloxacillin work by interfering with bacterial cell wall synthesis. Cloxacillin is specifically formulated to resist penicillinase, an enzyme some bacteria produce to inactivate penicillin antibiotics, thereby extending coverage to include penicillinase-producing Staphylococcus aureus.
Should not be used in patients with penicillin allergy. Common side effects include gastrointestinal symptoms like diarrhea, nausea, and potential allergic reactions. Effectiveness may be reduced when taken with food, so typically taken on an empty stomach. Full course must be completed as prescribed.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 27, 2026. · Read our editorial policy