Oxacillin
Oxacillin is a penicillinase-resistant penicillin antibiotic used primarily to treat infections caused by Staphylococcus aureus bacteria. It works by inhibiting bacterial cell wall synthesis and is particularly useful when beta-lactamase producing staph are suspected.
Oxacillin is a penicillin-type antibiotic used to treat staphylococcal infections by killing bacteria through cell wall inhibition.
Key facts at a glance
- ATC
- J01CF04
- RxNorm
- 7773
- Generic
- Oxacillin
- Class
- atc-j01
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- injection, solution, capsule, suspension
- 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.
Dosage and administration
- Usual dose
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
9 groupspregnancy
first trimesterstandard dosing
use only if clearly needed benefits outweigh potential risks
standard prenatal care
Use with caution and monitor for adverse effects.
pregnancy
second and third trimesterstandard dosing
use only if benefits outweigh risks
standard prenatal care
Use with caution and monitor for adverse effects.
lactation
breastfeedingstandard dosing
considered compatible with breastfeeding
monitor infant for diarrhea or candidiasis
pediatric_age
neonatesadjust dose based on weight and gestational age
reduce dose in premature infants due to immature renal function
monitor renal function and drug levels
Use with caution and monitor for adverse effects.
pediatric_age
infants and childrenweight-based dosing
standard pediatric dosing applies
routine monitoring
geriatric
elderlymonitor renal function adjust if needed
assess renal function before dosing
monitor renal function
Use with caution and monitor for adverse effects.
renal_impairment
mild to moderateno significant adjustment needed
monitor renal function
monitor renal function
Use with caution and monitor for adverse effects.
renal_impairment
severereduce dose extend interval
consider dose reduction and extended dosing interval
monitor drug levels and renal function
Use with caution and monitor for adverse effects.
hepatic_impairment
moderate to severeconsider dose reduction
use with caution monitor liver function
monitor liver function tests
Use with caution and monitor for adverse effects.
Statistics and clinical data
Drug class
Antibiotic classification based on ATC system
First FDA approval
Initial drug approval information
Common uses
Primary therapeutic indications
Mechanism of action
Pharmacodynamic mechanism
Treatment of skin and soft tissue infections, bone and joint infections, pneumonia, and septicemia caused by penicillinase-producing Staphylococcus aureus. May also be used for other susceptible gram-positive organisms.
Oxacillin binds to penicillin-binding proteins (PBPs) in bacterial cell walls, inhibiting transpeptidation and preventing cross-linking of peptidoglycan chains. This weakens the cell wall, leading to bacterial cell death. It is resistant to inactivation by penicillinase enzymes.
Use with caution in patients with penicillin allergy due to cross-reactivity. Monitor for hepatotoxicity, nephrotoxicity, and hematologic effects during prolonged therapy. Administered intravenously or intramuscularly. Not effective against methicillin-resistant Staphylococcus aureus (MRSA) or gram-negative bacteria.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
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 24, 2026. · Read our editorial policy