Hopkins ABX Guide

Oxacillin Antibiotic

What is Oxacillin and When It is Used?

Also known as oxacillin sodium, oxacillin is an antibiotic from the penicillin group of antibiotics. Developed by the British pharmaceutical company Beecham Group in the 1960s, the drug is used to treat a number of bacterial infections. Just like methicillin which it replaced, oxacillin belongs to the so-called penicillinase-resistant beta-lactam antibiotics. It works by inhibiting the growth of disease causing bacteria.

The antibiotic is effective against a number of pathogenic bacteria including Staphylococcus aureus. But the widespread use of its predecessor - methicillin - and oxacillin itself led to the development of strains that are resistant to both types of antibiotics: MRSA.

How is Oxacillin Taken/Administered?

This antibiotic is either taken orally - usually every 8 to 12 hours - or is administered by an injection at the intervals of 4 to 6 hours, depending on the type, location and severity of the infection. The duration of oxacillin therapy depends on the severity of the infection and the patient’s response to the medication.

Side Effects and Warnings

Oxacillin is well tolerated and generally doesn’t cause severe side effects. The most common side effect are pain and redness at the site of the injection. However, serious side effects aren’t impossible and it is highly important to seek medical help if experiencing changes in the colour or/and amount of urine, yellowing of the skin or/and eyes, severe stomach pain, joint or muscle soreness, or lethargy.

In rare cases, oxacillin can trigger an intestinal bacterial infection with severe diarrhoea which can occur during or after the treatment, sometimes several months after receiving the last dosage. Severe allergic reactions are rare but if developing a rash, shortness of breath or swelling in the face or mouth, seek medical attention right away.

Though it is often used in combination with other medications, it is important to be aware that there is always a risk of interaction. Therefore it is of utmost importance to notify the doctor if taking any medications - both prescription and nonprescription ones - as well as dietary supplements or herbal remedies. It is also very important to tell the doctor if having any health problems/underlying conditions, allergies to food or medications, or if being pregnant or breast-feeding.