Oxacillin 2gm Inj, 1 Vial
It is used to treat bacterial infections.
Drug Class
Antibiotic
Pharmacologic Class
Penicillin; Beta-lactam antibiotic
Pregnancy Category
Category B
FDA Approved
Jun 1961
DEA Schedule
Not Controlled
Overview
What is this medicine?
Oxacillin is an antibiotic used to treat serious bacterial infections, especially those caused by Staphylococcus bacteria that are resistant to other penicillins. It works by killing the bacteria that cause the infection.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided to you. It is essential to follow the instructions carefully. This medication can be administered in two ways: as an injection into a muscle or as an infusion into a vein over a period of time. In some cases, it may also be given as a direct injection into a vein.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the best storage method.
Missing a Dose
If you miss a dose, contact your doctor to find out what steps to take next.
To use this medication correctly, follow your doctor's instructions and read all the information provided to you. It is essential to follow the instructions carefully. This medication can be administered in two ways: as an injection into a muscle or as an infusion into a vein over a period of time. In some cases, it may also be given as a direct injection into a vein.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the best storage method.
Missing a Dose
If you miss a dose, contact your doctor to find out what steps to take next.
Lifestyle & Tips
- Complete the entire course of medication as prescribed, even if you feel better, to prevent the infection from returning and to reduce the risk of antibiotic resistance.
- Report any signs of allergic reaction (rash, itching, swelling, difficulty breathing) immediately.
- Report severe or persistent diarrhea, as this could be a sign of a more serious infection (Clostridioides difficile-associated diarrhea).
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
2 grams IV every 4-6 hours
Dose Range:
1 - 2 mg
Condition-Specific Dosing:
severeInfections:
2 grams IV every 4 hours
moderateInfections:
1-2 grams IV every 4-6 hours
endocarditis:
2 grams IV every 4 hours
Pediatric Dosing
Neonatal:
25-50 mg/kg/dose IV every 8-12 hours (adjust based on gestational age and postnatal age)
Infant:
100-200 mg/kg/day IV divided every 4-6 hours
Child:
100-200 mg/kg/day IV divided every 4-6 hours (max 12 g/day)
Adolescent:
1-2 grams IV every 4-6 hours (or adult dosing)
Dose Adjustments
Renal Impairment:
Mild:
No adjustment needed (CrCl > 50 mL/min)
Moderate:
No adjustment needed (CrCl 10-50 mL/min), but monitor for accumulation with prolonged use.
Severe:
Reduce dose or extend interval (e.g., 1-2 grams IV every 8-12 hours for CrCl < 10 mL/min)
Dialysis:
Administer after dialysis; supplemental dose may be needed. Hemodialysis removes a significant amount.
Hepatic Impairment:
Mild:
No specific adjustment needed
Moderate:
No specific adjustment needed
Severe:
Use with caution; monitor liver function tests. Dose adjustment generally not required unless concomitant renal impairment.
Pharmacology
Mechanism of Action
Oxacillin is a penicillinase-resistant penicillin that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs) located inside the bacterial cell wall. This binding prevents the cross-linking of peptidoglycan units, leading to the inhibition of cell wall synthesis and ultimately bacterial cell lysis and death.
Pharmacokinetics
Absorption:
Bioavailability:
Not applicable (IV administration)
Tmax:
Not applicable (IV administration, peak levels achieved rapidly)
FoodEffect:
Not applicable (IV administration)
Distribution:
Vd:
0.3-0.4 L/kg
ProteinBinding:
90-95%
CnssPenetration:
Limited (increases with inflamed meninges)
Elimination:
HalfLife:
0.5-1.5 hours (prolonged in renal impairment)
Clearance:
Approximately 200-300 mL/min
ExcretionRoute:
Primarily renal (tubular secretion and glomerular filtration); some biliary excretion
Unchanged:
30-60% (renal)
Pharmacodynamics
OnsetOfAction:
Rapid (within minutes of IV administration)
PeakEffect:
End of infusion
DurationOfAction:
Dependent on half-life and MIC of pathogen, typically requires frequent dosing (q4-6h)
Safety & Warnings
Side Effects
Important Side Effects to Report to Your Doctor Immediately
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you experience any of the following symptoms, seek medical attention right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Signs of kidney problems, such as:
+ Inability to pass urine
+ Changes in urine output
+ Blood in the urine
+ Sudden weight gain
Severe dizziness or fainting
Muscle or joint pain
Mouth irritation
Feeling extremely tired or weak
Severe stomach pain
Twitching
Seizures
Diarrhea, especially if it is severe, bloody, or accompanied by stomach pain or cramps (a rare but potentially life-threatening condition called C. diff-associated diarrhea, or CDAD, may occur during or after antibiotic treatment)
Unexplained bruising or bleeding, signs of infection (such as fever, chills, or sore throat), or feeling extremely tired or weak, which may indicate low blood cell counts
Other Possible Side Effects
Most people do not experience significant side effects, but some may occur. If you experience any of the following side effects, or if they persist or bother you, contact your doctor:
Diarrhea
Upset stomach or vomiting
* Change in tongue color
This is not an exhaustive list of potential side effects. If you have questions or concerns, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you experience any of the following symptoms, seek medical attention right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Signs of kidney problems, such as:
+ Inability to pass urine
+ Changes in urine output
+ Blood in the urine
+ Sudden weight gain
Severe dizziness or fainting
Muscle or joint pain
Mouth irritation
Feeling extremely tired or weak
Severe stomach pain
Twitching
Seizures
Diarrhea, especially if it is severe, bloody, or accompanied by stomach pain or cramps (a rare but potentially life-threatening condition called C. diff-associated diarrhea, or CDAD, may occur during or after antibiotic treatment)
Unexplained bruising or bleeding, signs of infection (such as fever, chills, or sore throat), or feeling extremely tired or weak, which may indicate low blood cell counts
Other Possible Side Effects
Most people do not experience significant side effects, but some may occur. If you experience any of the following side effects, or if they persist or bother you, contact your doctor:
Diarrhea
Upset stomach or vomiting
* Change in tongue color
This is not an exhaustive list of potential side effects. If you have questions or concerns, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe allergic reaction (anaphylaxis): difficulty breathing, swelling of face/throat, severe rash, dizziness.
- Severe diarrhea (watery or bloody stools), abdominal cramps, fever.
- New or worsening fever, chills, sore throat, or unusual bruising/bleeding (signs of blood dyscrasias).
- Yellowing of skin or eyes, dark urine, severe stomach pain (signs of liver problems).
- Decreased urination, swelling in ankles/feet (signs of kidney problems).
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced.
If you are allergic to penicillin, as this may be relevant to your treatment.
* If you are currently taking tetracycline, as this may interact with the medication.
Please note that this is not an exhaustive list of potential interactions. To ensure your safety, it is crucial to discuss all of your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. Additionally, inform them about any existing health problems.
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to confirm that it is safe to do so. This will help prevent potential interactions and ensure the safe use of this medication.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced.
If you are allergic to penicillin, as this may be relevant to your treatment.
* If you are currently taking tetracycline, as this may interact with the medication.
Please note that this is not an exhaustive list of potential interactions. To ensure your safety, it is crucial to discuss all of your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. Additionally, inform them about any existing health problems.
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to confirm that it is safe to do so. This will help prevent potential interactions and ensure the safe use of this medication.
Precautions & Cautions
Important Warnings and Cautions for Patients Taking This Medication
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
If you are taking this medication long-term, your doctor may recommend regular blood tests to monitor your condition. Be sure to discuss this with your doctor.
Do not take this medication for longer than prescribed, as this may increase the risk of a second infection.
If you are following a low-sodium or sodium-free diet, consult your doctor before taking this medication, as some products may contain sodium.
Patients 65 years or older should exercise caution when taking this medication, as they may be more susceptible to side effects.
If you are pregnant, planning to become pregnant, or are breastfeeding, inform your doctor to discuss the potential benefits and risks to you and your baby.
Special Considerations for Children
When administering this medication to children, use with caution, as they may be at a higher risk of experiencing certain side effects.
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
If you are taking this medication long-term, your doctor may recommend regular blood tests to monitor your condition. Be sure to discuss this with your doctor.
Do not take this medication for longer than prescribed, as this may increase the risk of a second infection.
If you are following a low-sodium or sodium-free diet, consult your doctor before taking this medication, as some products may contain sodium.
Patients 65 years or older should exercise caution when taking this medication, as they may be more susceptible to side effects.
If you are pregnant, planning to become pregnant, or are breastfeeding, inform your doctor to discuss the potential benefits and risks to you and your baby.
Special Considerations for Children
When administering this medication to children, use with caution, as they may be at a higher risk of experiencing certain side effects.
Overdose Information
Overdose Symptoms:
- Neuromuscular hyperexcitability (e.g., twitching, myoclonus, seizures), especially with very high doses or in patients with renal impairment.
- Nausea, vomiting, diarrhea.
What to Do:
Seek immediate medical attention or call a poison control center (1-800-222-1222). Treatment is supportive and symptomatic. Hemodialysis may be used to remove oxacillin from the blood in severe cases, especially with renal failure.
Drug Interactions
Major Interactions
- Methotrexate (increased methotrexate levels and toxicity due to competition for renal tubular secretion)
- Warfarin (may alter INR, requiring close monitoring)
Moderate Interactions
- Probenecid (decreases renal tubular secretion of oxacillin, increasing and prolonging serum levels)
- Tetracyclines (may antagonize the bactericidal effect of penicillins)
- Oral Contraceptives (may reduce efficacy, though evidence is weak for penicillins)
Monitoring
Baseline Monitoring
Renal function (BUN, creatinine)
Rationale: To establish baseline for dose adjustment in renal impairment and monitor for potential nephrotoxicity.
Timing: Prior to initiation of therapy
Liver function tests (ALT, AST, bilirubin)
Rationale: To establish baseline and monitor for potential hepatotoxicity (rare).
Timing: Prior to initiation of therapy
Complete Blood Count (CBC) with differential
Rationale: To establish baseline and monitor for potential hematologic abnormalities (e.g., leukopenia, eosinophilia, thrombocytopenia).
Timing: Prior to initiation of therapy
Routine Monitoring
Clinical response (fever, signs/symptoms of infection)
Frequency: Daily
Target: Resolution of infection symptoms
Action Threshold: Lack of improvement or worsening symptoms may indicate treatment failure or resistant organism.
Renal function (BUN, creatinine)
Frequency: Weekly (or more frequently in patients with pre-existing renal impairment or prolonged therapy)
Target: Within normal limits or stable from baseline
Action Threshold: Significant increase may require dose adjustment or discontinuation.
Liver function tests (ALT, AST, bilirubin)
Frequency: Weekly (for prolonged therapy or in patients with pre-existing hepatic impairment)
Target: Within normal limits or stable from baseline
Action Threshold: Significant elevation may require discontinuation.
Complete Blood Count (CBC) with differential
Frequency: Weekly (for prolonged therapy, >2 weeks)
Target: Within normal limits
Action Threshold: Significant changes (e.g., leukopenia, eosinophilia, thrombocytopenia) may require discontinuation.
Electrolytes (especially potassium)
Frequency: Periodically, especially with high doses or prolonged therapy
Target: Within normal limits
Action Threshold: Hypokalemia may occur with high doses.
Symptom Monitoring
- Signs of allergic reaction (rash, itching, hives, swelling, difficulty breathing)
- Diarrhea (especially severe or persistent, suggestive of C. difficile infection)
- Nausea/vomiting
- Fever or chills (if new onset or worsening)
- Signs of superinfection (e.g., oral thrush, vaginal yeast infection)
- Signs of phlebitis or irritation at injection site
Special Patient Groups
Pregnancy
Oxacillin is generally considered safe for use during pregnancy (Category B). Animal reproduction studies have not demonstrated a risk to the fetus, but there are no adequate and well-controlled studies in pregnant women. Use only if clearly needed.
Trimester-Specific Risks:
First Trimester:
No increased risk of congenital anomalies identified.
Second Trimester:
No specific risks identified.
Third Trimester:
No specific risks identified.
Lactation
Oxacillin is excreted in breast milk in small amounts. It is generally considered compatible with breastfeeding. Monitor the infant for potential adverse effects such as diarrhea, candidiasis (thrush, diaper rash), or allergic reactions.
Infant Risk:
Low risk (L2)
Pediatric Use
Use with caution in neonates and premature infants due to immature renal function, which may lead to prolonged half-life and increased drug accumulation. Dosage adjustments and close monitoring are necessary. Higher doses per kg are often required compared to adults due to faster elimination in older children.
Geriatric Use
No specific dose adjustment is typically needed based on age alone, but dose adjustments may be necessary for age-related decreases in renal function. Elderly patients may be more susceptible to adverse effects, particularly gastrointestinal disturbances and central nervous system effects at very high doses.
Clinical Information
Clinical Pearls
- Oxacillin is a narrow-spectrum penicillinase-resistant penicillin, primarily used for infections caused by Methicillin-Sensitive Staphylococcus aureus (MSSA). It is NOT effective against Methicillin-Resistant Staphylococcus aureus (MRSA).
- Administer IV slowly over 10-30 minutes to minimize vein irritation and phlebitis.
- High doses of oxacillin can cause hypokalemia; monitor potassium levels, especially in patients at risk.
- Although rare, oxacillin can cause drug-induced liver injury (cholestatic hepatitis); monitor LFTs, especially with prolonged therapy.
- Consider therapeutic drug monitoring (TDM) in critically ill patients or those with altered pharmacokinetics to ensure adequate drug exposure, though not routinely performed for oxacillin.
Alternative Therapies
- Nafcillin (another penicillinase-resistant penicillin, often interchangeable with oxacillin)
- Cefazolin (a first-generation cephalosporin, often used for MSSA infections, generally well-tolerated)
- Clindamycin (for MSSA, but resistance can be an issue)
- Vancomycin (if MRSA is suspected or confirmed, or for severe penicillin allergy)
Cost & Coverage
Average Cost:
Varies, typically $10-$50 per 2g vial
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (Generic)
General Drug Facts
If your symptoms or health problems persist or worsen, it is essential to contact your doctor promptly. To ensure safe use, never share your medication with others, and do not take medication prescribed for someone else. Store all medications in a secure location, out of reach of children and pets, to prevent accidental ingestion. Dispose of unused or expired medications properly. Unless instructed otherwise, avoid flushing medications down the toilet or pouring them down the drain. If you are unsure about the correct disposal method, consult your pharmacist for guidance. Many communities offer drug take-back programs, which your pharmacist can help you locate. Some medications may come with an additional patient information leaflet; check with your pharmacist to see if this applies to your prescription. If you have any questions or concerns about your medication, discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. Be prepared to provide information about the medication taken, the amount, and the time it was taken, as this will aid in providing appropriate care.