Oxacillin: uses, dosing, side effects & brands
Oxacillin is a penicillin-class antibacterial sold in the U.S. under 3 brand and generic names, for cellulitis, bacterial endocarditis and osteomyelitis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Penicillin-Class Antibacterial
- Treats (across its forms)
- Cellulitis, Bacterial Endocarditis and Osteomyelitis
- Available as
- Injectable · Capsule
- Sold as
- 3 products — Bactocill in Plastic Container, Oxacillin Sodium and Prostaphlin
- Prescription?
- Prescription only
- Generic available?
- Yes
How Bactocill in Plastic Container is dosed
From the FDA label for Bactocill in Plastic Container (application NDA050640). Other oxacillin products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Oxacillin Injection, USP supplied as a premixed frozen solution is to be administered as a continuous or intermittent intravenous infusion. The usual dose recommendation is as follows: Adults 250-500 mg I.V. every 4-6 hours (mild to moderate infections) 1 gram I.V. every 4-6 hours (severe infections) This container system may be inappropriate for the dosage requirements for children, infants and neonates. Other dosage forms may be more appropriate. Bacteriologic studies to determine the causative organisms and their susceptibility to oxacillin should always be performed. Duration of therapy varies with the type of severity of infection as well as the overall condition of the patient; therefore, it should be determined by the clinical and bacteriological response of the patient. In severe staphylococcal infections, therapy with oxacillin should be continued for at least 14 days. Therapy should be continued for at least 48 hours after the patient has become afebrile, asymptomatic, and cultures are negative. Treatment of endocarditis and osteomyelitis may require a longer duration of therapy. Concurrent administration of oxacillin and probenecid increases and prolongs serum penicillin levels. Probenecid decreases the apparent volume of distribution and slows the rate of excretion by competitively inhibiting renal tubular secretion of penicillin. Penicillin-probenecid therapy is…
Everything below is the FDA label for Bactocill in Plastic Container (injectable). Oxacillin is also sold as capsule, and those are different medicines to take — follow the label for the one you were prescribed.
Bactocill in Plastic Container side effects
Body as a Whole The reported incidence of allergic reactions to penicillin ranges from 0.7 to 10 percent (see WARNINGS ). Sensitization is usually the result of treatment but some individuals have had immediate reactions when first treated. In such cases, it is thought that the patients may have had prior exposure to the drug via trace amounts present in milk and vaccines. Two types of allergic reactions to penicillins are noted clinically, immediate and delayed. Immediate reactions usually occur within 20 minutes of administration and range in severity from urticaria and pruritus to angioneurotic edema, laryngospasm, bronchospasm, hypotension, vascular collapse and death. Such immediate anaphylactic reactions are very rare (see WARNINGS ) and usually occur after parenteral therapy but have occurred in patients receiving oral therapy. Another type of immediate reaction, an accelerated reaction, may occur between 20 minutes and 48 hours after administration and may include urticaria, pruritus, and fever. Although laryngeal edema, laryngospasm, and hypotension occasionally occur, fatality is uncommon. Delayed allergic reactions to penicillin therapy usually occur after 48 hours and sometimes as late as 2 to 4 weeks after initiation of therapy. Manifestations of this type of reaction include serum sickness-like symptoms ( i.e. , fever, malaise, urticaria, myalgia, arthralgia,…
Who shouldn’t take Bactocill in Plastic Container
A history of a hypersensitivity (anaphylactic) reaction to any penicillin is a contraindication. Solutions containing dextrose may be contraindicated in patients with known allergy to corn or corn products.
Bactocill in Plastic Container drug interactions
Tetracycline, a bacteriostatic antibiotic, may antagonize the bactericidal effect of penicillin and concurrent use of these drugs should be avoided. Oxacillin blood levels may be prolonged by concurrent administration of probenecid which blocks the renal tubular secretion of penicillins.
Every oxacillin product we track (3)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | Not yet rated | Prescription | Injectable | No data | — | View → | |
| 2 | Not yet rated | Prescription | Injectable | No data | — | View → | |
| 3 | Not yet rated | Prescription | Capsule | No data | — | View → |
Oxacillin and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for oxacillin: levels in milk, effects in breastfed infants, and the drugs it would consider insteadLimited information indicates that oxacillin produces low levels in milk that are not expected to cause adverse effects in breastfed infants. Occasionally disruption of the infant's gastrointestinal flora, resulting in diarrhea or thrush have been reported with penicillins, but these effects have not been adequately evaluated. Oxacillin is acceptable in nursing mothers.
National Institute of Child Health and Human Development, record revised November 15, 2024. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about oxacillin
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 169 reports naming oxacillin, and the FDA flagged 86% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- drug reaction with eosinophilia and systemic symptoms17 reports
- hepatic cytolysis11 reports
- toxic epidermal necrolysis11 reports
- pyrexia10 reports
- drug-induced liver injury9 reports
- diarrhoea8 reports
- eosinophilia8 reports
- rash8 reports
Read these as a signal, not a rate. A report does not mean oxacillin caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved August 25, 2026.
Related calculators
Frequently asked questions
What is Bactocill in Plastic Container?
Bactocill in Plastic Container (Oxacillin Sodium) is a penicillin-class antibacterial used to treat Cellulitis, Bacterial Endocarditis, Osteomyelitis, Postoperative Complications.
What kind of drug is oxacillin?
The FDA classifies oxacillin as a penicillin-class antibacterial. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take oxacillin with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run oxacillin against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is oxacillin sold under?
We track 3 oxacillin-containing products in the U.S.: Bactocill in Plastic Container, Oxacillin Sodium and Prostaphlin. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does oxacillin come in?
Across the brands we track, oxacillin is currently marketed as injectable and capsule, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic oxacillin?
Yes. Our catalog lists 1 generic oxacillin product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Oxacillin: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/oxacillin
- MLA
- “Oxacillin: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/oxacillin.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for oxacillin on DailyMed (NIH) ↗.