Oxacillin
BACTOCILL
What it isPenicillinase-resistant penicillin; methicillin-susceptible staphylococcal infection.
Why this oneIt is nafcillin's close efficacy peer; selection usually turns on formulary and tolerability rather than antibacterial reach.
What limits itHepatotoxicity and interstitial nephritis stand out. It does not cover MRSA and requires frequent administration.
FDA-approved for
- staphylococcal infections (MSSA) (1962)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Staphylococcal infection, mild-moderate | Adults | 250-500 mg IV q4-6h | 250-500 mg IV q4-6h | |
| Severe infection | Adults | 1 g IV q4-6h | 1 g IV q4-6h |
Renal Undefined
Hepatic Undefined
Instructions
- Administer as continuous or intermittent IV infusion
- Premixed frozen container inappropriate for children/infants/neonates — use other dosage forms
- Severe staph infections: continue at least 14 days and for ≥48 h after afebrile, asymptomatic, and cultures negative
Contraindications
- History of anaphylactic/hypersensitivity reaction to any penicillin
- Dextrose-containing solutions may be contraindicated in patients with corn allergy
Cautions
- Serious/fatal anaphylactic reactions; cross-sensitivity with other beta-lactams
- Thrombophlebitis with IV use, especially in elderly
Adverse reactions
- Allergic reactions: urticaria, pruritus, angioedema, laryngospasm, bronchospasm, hypotension, anaphylaxis
Pregnancy Animal studies show no fetal harm; no adequate well-controlled human studies
Lactation Undefined
NO BOXED WARNINGS
Principal riskHepatotoxicity; interstitial nephritis
Cost, est. cash$10–$500/month
Generic entryPre-1982
Classes and tags
Clinical profile
Legacy pregnancy categoryB
Defining liabilityAllergy, gastrointestinal effects and agent-specific renal, hepatic, hematologic or interaction risks.
Mechanism of action: Oxacillin ballicule
