Administration: IM injection, IV injection, IV infusion. IM injections of oxacillin sodium should be made deeply into a large muscle. IV injection should be slow for about 10 minutes. For IV infusion, additives should not be introduced into the injection. 

Adult Dosage

+ For the treatment of infections: the usual adult IM or IV dosage of oxacillin is 250–1000 mg every 4–6 hours.

+ For the treatment septicaemia or meningitis due to bacteria: adult IV dosage of oxacillin is 1-2 g every 4 hours.

Pediatric Dosage

Children weighing 40 kg or more: IM injection or IV injection, 250 mg – 1 g every 4-6 hours. 

Children weighing less than 40 kg: IM injection or IV injection, 12,5 25 mg/kg body weight every 6 hours or 16,7 mg/kg body weight every 4 hours. 

Children over 1 month of age and weighing less than 40 kg: 100-200 mg/kg daily in equally divided doses every 4-6 hours for the treatment of severe infections. 

– Dosage in patients with Renal Impairment

Dosage should be adjusted in patients with creatinine clearances less than 10 ml/minutes

– Duration of Therapy

The duration of oxacillin therapy depends on the type and severity of infection and should be determined by the clinical and bacteriologic response of the patient. In serious staphylococcal infections, therapy should be continued for at least 1–2 weeks; more prolonged therapy is necessary for the treatment of osteomyelitis or endocarditis.