Oxacillin

Uses

What is oxacillin used for?

Oxacillin sodium is an antibiotic under the class of penicillin. It is a semisynthetic form of penicillin that has penicillinase resistance and is acid-stable. Like other penicillins, oxacillin works by binding to penicillin-binding proteins embedded on the inner membrane of the cell wall of certain bacteria. This weakens and deforms the structure of the bacterium, causing it to be destroyed.

Oxacillin is indicated mainly to treat Staphylococcal infections that are resistant to benzylpenicillin. There are over 30 species of Staphylococcus, with S. aureus causing the majority of these infections.

Staph bacteria cause infections such as:

• Cutaneous (skin) infection
• Sepsis (infection in the blood with accompanied immune response)
• Osteitis (bone) infection
• Endocarditis (the inner lining of the heart muscles)
• Food poisoning
• Pneumonia
• Toxic shock syndrome (commonly attributed to tampon use)

How should I take oxacillin?

Oxacillin is primarily available in the parenteral (IV/IM) dosage form. This medication requires reconstitution with sterile water for injection prior to administration. Once reconstituted, this drug should be administered immediately. Do not take parenteral medications by mouth or by other routes.

How do I store oxacillin?

This drug should be stored at room temperature (20-25°C) and be protected from light. Do not allow this product to freeze. Always check the label before using this product. For safety, keep out of the reach of children and pets.

Do not use if the printed expiration date has passed, the vial seal has been broken, or the product has changed in color, odor, or consistency.

Do not dispose of this product by pouring it down the drain, toilet, or into the environment. Ask your pharmacist regarding the proper way and location of disposal.

Precautions & warnings

What should I know before using oxacillin?

Before using this medication, inform your doctor if:

• You have ever had an allergic reaction to oxacillin or any penicillin
• You have a history of allergy to other medications, food, or other substances
• You are taking other medications
• You have underlying health conditions

Is it safe during pregnancy or breastfeeding?

This drug is a pregnancy category B drug. Human and animal studied have not shown evidence of causing fetal or reproductive harm. This drug should only be used during pregnancy if there is a clear need and the potential benefits outweigh the potential risks, as determined by your doctor.

This drug is excreted in breast milk. Do not breastfeed or pump milk for storage while taking this medication.

Side effects

What side effects can occur when using oxacillin?

All drugs have the potential to elicit side effects even with normal use. Many side effects are dose-related and will resolve when it is adjusted or at the end of therapy.

While this medication is specific for killing bacteria. While side effects are not likely, some side effects include:

• Gastrointestinal upset
  • Nausea
  • Vomiting
  • Diarrhea
  • Clostridium difficile-associated diarrhea or pseudomembranous colitis (potentially fatal)
• Allergic reaction
  • Fever
  • Rash
  • Leukopenia
• Anaphylaxis (potentially fatal)
  • Trouble breathing
  • Tightening or collapse of airways
• Hepatotoxicity
  • Increased AST
• Acute interstitial nephritis
  • Hematuria
• Serum sickness-like reactions

You may experience some, none, or other side effects not mentioned above. If you have any concerns about a side effect or it becomes bothersome, consult your doctor or pharmacist.

Interactions

What drugs may interact with oxacillin?

This drug may interact with other medications. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist.

Known drugs and their interactions with oxacillin include:

• Caffeine citrate
• Sodium bicarbonate
• Verapamil
• Doxapram
• Vitamin B complex with vitamin C
• Tetracycline
• Probenecid

If you experience an adverse drug interaction, stop taking this drug and continue taking your other medication. Inform your doctor immediately to reevaluate your treatment plan. Your dose may need to be adjusted, substituted with another drug, or discontinue using the drug.

Does food or alcohol interact with oxacillin?

The oral form of this drug should be taken on an empty stomach for optimal absorption, as food may reduce the amount of drug that is absorbed. It can be taken 1-2 hours before or 2-3 hours after meals. Parenteral dosage forms can be administered without regard to the timing of meals. There are no notable interactions with alcohol with this drug.

Inform your doctor or pharmacist if you have any concerns regarding food-drug interactions.

What health conditions may interact with oxacillin?

This drug should be taken with caution if you have any of the following conditions:

• Hypersensitivity to β-lactams
• Asthma

Inform your doctor or pharmacist if you have any concerns regarding specific health conditions.

Dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using oxacillin.

What is the dose of oxacillin for an adult?

For reconstitution of the suspension

Intramuscular (IM)

• Add 5.7 mL or 11.4 mL of sterile water for injection to the vial containing 1 g or 2 g of oxacillin, respectively, to create a solution containing 167 mg/mL (250 mg/1.5 mL).

Intravascular (IV)

• Add 10 mL or 20 mL of sterile water for injection or NaCl 0.45% or 0.9% injection to the vial containing 1 g or 2 g of oxacillin, respectively.
• For IV infusion, dilute further with a compatible IV solution to a concentration of 0.5-40 mg/mL.

For infections due to benzylpenicillin-resistant staphylococci

Oral

• Take 1 g twice a day

Parenteral

• Administer 250-500 mg every 4 to 6 hours, by IM, slow IV injection over 10 minutes or IV infusion.
• May increase the dose to 1 g given 4 to 6 hours for severe infections.

What is the dose of oxacillin for a child?

For infections due to benzylpenicillin-resistant staphylococci

Parenteral

• Body weight <40 kg: 50-100 mg/kg/day administered via IV in divided doses.
• Premature and neonate babies: 25 mg/kg/day administered via IV

How is oxacillin available?

This drug is available in the following brands, dosage forms and strengths:

• Cilvex powder for injection 500 mg/vial
• Oxal powder for injection 500 mg/vial
• Oxan powder for injection 500 mg/vial
• Oxapen powder for injection 500 mg/vial
• Wydox powder for injection 500 mg/vial

What should I do in case of an emergency or overdose?

Symptoms of overdose are the same as those described under “Side effects”. If signs or symptoms occur, discontinue use of the medication, treat symptomatically, and institute appropriate supportive measures.

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of this drug, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.