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Methylphenyl Isoxazolyl Penicillin (Generic Oxacillin Injection)

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Why is this medication prescribed?

Oxacillin is a prescription antibiotic medication that belongs to the penicillin class of antibiotics. It is primarily prescribed to treat bacterial infections caused by susceptible organisms. Oxacillin is often used to treat infections caused by penicillinase-producing staphylococci, which are bacteria that produce an enzyme called penicillinase that can destroy penicillin antibiotics.

Here are some common reasons why Oxacillin Injection may be prescribed:

  • Skin and Soft Tissue Infections: Oxacillin can be used to treat skin and soft tissue infections caused by susceptible bacteria, including cellulitis, impetigo, and abscesses.
  • Respiratory Tract Infections: It may be used for respiratory tract infections, such as pneumonia, bronchitis, and lung abscesses, caused by susceptible bacteria.
  • Bone and Joint Infections: Oxacillin can be prescribed for bone and joint infections, such as osteomyelitis and septic arthritis, when caused by susceptible organisms.
  • Endocarditis: It is sometimes used as part of the treatment regimen for infective endocarditis, a serious heart valve infection.
  • Bloodstream Infections: In cases of bacteremia (bacteria in the bloodstream), Oxacillin may be administered intravenously.

How should this medicine be used?

Here are some general guidelines for the use of Oxacillin Injection:

  • Dosage: The dosage of Oxacillin will depend on the specific infection being treated, the patient’s age, weight, and overall health, as well as the severity of the infection. Your healthcare provider will determine the appropriate dosage for your condition.
  • Administration: Oxacillin is typically administered by a healthcare professional in a hospital or clinical setting. It can be given as an IV infusion or as an IM injection, depending on the healthcare provider’s instructions.
  • Frequency: The frequency of administration will also be determined by your healthcare provider. It is important to follow the prescribed dosing schedule and complete the entire course of treatment, even if you start feeling better before it’s finished.
  • Follow Directions: Always follow your healthcare provider’s instructions regarding the preparation and administration of Oxacillin. The medication may need to be diluted before administration, and it should be administered slowly over a specified period.
  • Duration of Treatment: The duration of treatment with Oxacillin will vary depending on the type and severity of the infection. It’s crucial to complete the full course of treatment to ensure that the infection is completely eradicated.
  • Monitoring: While receiving Oxacillin, your healthcare provider will monitor your progress and may perform tests to check the effectiveness of the medication. Be sure to keep all scheduled follow-up appointments.
  • Allergic Reactions: Inform your healthcare provider if you have a history of allergies to antibiotics, especially penicillin or cephalosporin antibiotics, as Oxacillin belongs to the penicillin class. If you experience signs of an allergic reaction (e.g., rash, itching, swelling, severe dizziness, difficulty breathing), seek immediate medical attention.
  • Precautions: Tell your healthcare provider about any other medications, supplements, or medical conditions you have, as they can affect the safety and efficacy of Oxacillin. It’s essential to provide a complete medical history.
  • Adverse Effects: Like all medications, Oxacillin may have side effects. Common side effects may include nausea, vomiting, diarrhea, and injection site reactions. If you experience severe or unusual side effects, contact your healthcare provider.

Please note that this is just general information, and you should always follow your healthcare provider’s specific instructions and guidance when using Oxacillin Injection or any medication. They will provide you with personalized dosing and administration instructions based on your individual medical condition.

Other uses for this medicine

Oxacillin is primarily used for the treatment of bacterial infections caused by susceptible organisms. These infections may include:

  • Skin and soft tissue infections
  • Respiratory tract infections
  • Bone and joint infections
  • Bloodstream infections (bacteremia)
  • Certain types of pneumonia
  • Endocarditis (heart valve infection)
  • Other serious bacterial infections

Oxacillin is a narrow-spectrum antibiotic and is specifically designed to target certain types of bacteria, including Staphylococcus aureus that are resistant to other forms of penicillin. It is not typically used for viral infections like the common cold or flu, as antibiotics are ineffective against viral infections.

What special precautions should I follow?

Special precautions to follow when using Oxacillin Injection include:

  • Allergy and Sensitivity: Inform your healthcare provider if you have a known allergy to Oxacillin, other penicillin antibiotics, or cephalosporins, as you may be at an increased risk of an allergic reaction.
  • Kidney Function: If you have kidney problems, your healthcare provider may need to adjust the dosage of Oxacillin or monitor your kidney function during treatment.
  • Liver Function: Oxacillin is primarily excreted through the liver. If you have liver disease or impaired liver function, your healthcare provider may need to adjust the dosage.
  • Antibiotic Resistance: Overuse or misuse of antibiotics, including Oxacillin, can lead to antibiotic resistance. It’s important to take the medication exactly as prescribed and complete the full course of treatment, even if you start feeling better.
  • Side Effects: Be aware of potential side effects of Oxacillin, which can include diarrhea, nausea, vomiting, rash, and allergic reactions. If you experience severe or persistent side effects, contact your healthcare provider.
  • Drug Interactions: Inform your healthcare provider about all other medications, supplements, and herbal products you are taking, as Oxacillin can interact with other drugs.
  • Pregnancy and Breastfeeding: Discuss with your healthcare provider if you are pregnant, planning to become pregnant, or breastfeeding, as there may be considerations regarding the use of Oxacillin during these periods.

Always follow your healthcare provider’s instructions and advice regarding the use of Oxacillin Injection, and do not hesitate to ask any questions or express concerns you may have about the medication or its potential risks and benefits.

What special dietary instructions should I follow?

There are generally no specific dietary restrictions associated with Oxacillin. However, it’s essential to follow a balanced diet and stay hydrated to support your body’s recovery from the infection. Discuss any dietary concerns or drug interactions with your healthcare provider or pharmacist.

What should I do if I forget a dose?

  • If you miss a dose, take it as soon as you remember. If it’s close to the time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule.
  • Do not double the dose to catch up for a missed one, as this can increase the risk of side effects and may not improve the antibiotic’s effectiveness.
  • If you have questions or concerns about missed doses, contact your healthcare provider or pharmacist for guidance.

What side effects can this medication cause?

Oxacillin is a type of antibiotic medication that is used to treat bacterial infections. Like all medications, oxacillin can cause side effects. It’s important to note that not everyone will experience these side effects, and some people may experience different side effects to varying degrees of severity. Common side effects of oxacillin injection may include:

  • Pain or irritation at the injection site: This is a common side effect of many injectable medications.
  • Nausea and vomiting: Some people may experience gastrointestinal symptoms such as nausea and vomiting.
  • Diarrhea: Diarrhea is another possible gastrointestinal side effect.
  • Skin rash: Skin rashes, itching, or hives may occur as a reaction to the medication.
  • Fever: An elevation in body temperature may occur as a response to the infection or as a side effect of the medication.
  • Allergic reactions: In rare cases, people may experience severe allergic reactions to oxacillin, which can include difficulty breathing, swelling of the face or throat, and a rapid heartbeat. This is a medical emergency and requires immediate attention.
  • Liver problems: Oxacillin can sometimes affect liver function, leading to symptoms such as jaundice (yellowing of the skin and eyes), dark urine, or abdominal pain. These symptoms should be reported to a healthcare provider.
  • Blood disorders: Oxacillin can rarely cause changes in blood cell counts, leading to conditions like leukopenia (low white blood cell count), thrombocytopenia (low platelet count), or anemia (low red blood cell count). Symptoms of these conditions may include weakness, unusual bleeding or bruising, or frequent infections.
  • Kidney problems: Kidney damage is a rare side effect of oxacillin. Signs of kidney problems may include changes in urine output, swelling, or pain in the lower back or sides.
  • Clostridium difficile infection: Antibiotics like oxacillin can disrupt the balance of bacteria in the digestive tract, potentially leading to an overgrowth of Clostridium difficile bacteria, which can cause severe diarrhea and colitis (inflammation of the colon).

It’s essential to take oxacillin exactly as prescribed by your healthcare provider and to report any unusual or severe side effects to them promptly. If you experience signs of a severe allergic reaction, such as difficulty breathing or swelling of the face, seek immediate medical attention.

What should I know about storage and disposal of this medication?


  • Follow Instructions: Always store the medication as per the instructions provided on the label or as directed by your healthcare provider or pharmacist.
  • Refrigeration: In most cases, Oxacillin Injection should be stored in the refrigerator between 36°F to 46°F (2°C to 8°C). Check the packaging or ask your pharmacist for specific storage recommendations as it may vary depending on the manufacturer.
  • Protect from Light: Keep the medication in its original packaging or container to protect it from light. Some medications can degrade when exposed to light.
  • Keep Out of Reach of Children: Store Oxacillin Injection in a secure place, out of the reach of children and pets. It’s important to prevent accidental ingestion.
  • Avoid Freezing: Do not freeze the medication. Freezing can alter the composition and effectiveness of the medication.


  • Dispose of Unused Medication: If you have any unused or expired Oxacillin Injection, do not keep it for future use. Properly dispose of it to prevent unintentional use or misuse.
  • Follow Local Regulations: Dispose of medication in accordance with local regulations and guidelines. Many areas have take-back programs or specific instructions for the disposal of medications.
  • Do Not Flush: Do not flush medications down the toilet unless specifically instructed to do so. Flushing can contaminate water sources.
  • Use a Medication Disposal Service: Some pharmacies and healthcare facilities offer medication disposal services. You can inquire with them about the safe disposal of your unused medication.

In case of emergency/overdose

If you suspect an overdose or experience severe side effects from Oxacillin Injection, seek emergency medical attention immediately. Symptoms of an overdose or severe reaction may include:

  • Difficulty breathing or shortness of breath
  • Swelling of the face, lips, tongue, or throat
  • Severe dizziness or lightheadedness
  • Rapid or irregular heartbeat
  • Unusual bleeding or bruising
  • Extreme weakness or fatigue

What other information should I know

  • Inform your healthcare provider about any allergies or sensitivities you may have before starting Oxacillin Injection.
  • Take the full course of the medication as prescribed by your healthcare provider, even if your symptoms improve before the medication is finished. Stopping antibiotics prematurely can lead to antibiotic resistance.
  • If you miss a dose, contact your healthcare provider or pharmacist for instructions on what to do next.
  • Inform your healthcare provider about all other medications, supplements, and herbal products you are taking, as there can be interactions with Oxacillin Injection.
  • Follow your healthcare provider’s recommendations for follow-up care and monitoring while taking this medication.

Always consult your healthcare provider or pharmacist for specific guidance on the storage, disposal, and usage of Oxacillin Injection based on your individual circumstances and the specific product you have.

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