The penicillinase-resistant penicillins are indicated in the treatment of infections caused by penicillinase-producing staphylococci which have demonstrated susceptibility to the drugs.

Culture and susceptibility tests should be performed initially to determine the causative organism and their sensitivity to the drug (See CLINICAL PHARMACOLOGY – Susceptibility Plate Testing).The penicillinase-resistant penicillins may be used to initiate therapy in suspected cases of resistant staphylococcal infections prior to the availability of laboratory test results.

The penicillinase-resistant penicillins should not be used in infections caused by organisms susceptible to penicillin G.

If the susceptibility tests indicate that the infection is due to an organism other than a resistant staphylococcus, therapy should not be continued with a penicillinase-resistant penicillin.To reduce the development of drug-resistant bacteria and maintain the effectiveness of Oxacillin for Injection and other antibacterial drugs, Oxacillin for Injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.

When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy.

In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

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Infection -- Invasion of the host organism by microorganisms that can cause pathological conditions or diseases.

Unspecified Staphylococcus infection in conditions classified elsewhere and of unspecified site --

Staphylococcal Infections -- Infections with bacteria of the genus STAPHYLOCOCCUS.

Communicable Diseases -- broad class of diseases whose causative agents may be passed between individuals in many different ways.

A history of a hypersensitivity (anaphylactic) reaction to any penicillin is a contraindication.

Serious and occasionally fatal hypersensitivity (anaphylactic shock with collapse) reactions have occurred in patients receiving penicillin.

The incidence of anaphylactic shock in all penicillin-treated patients is between 0.015 and 0.04 percent.

Anaphylactic shock resulting in death has occurred in approximately 0.002 percent of the patients treated.

Although anaphylaxis is more frequent following a parenteral administration, it has occurred in patients receiving oral penicillins.When penicillin therapy is indicated, it should be initiated only after a comprehensive patient drug and allergy history has been obtained.

If an allergic reaction occurs, the drug should be discontinued and the patient should receive supportive treatment, eg, artificial maintenance of ventilation, pressor amines, antihistamines, and corticosteroids.

Individuals with a history of penicillin hypersensitivity may also experience allergic reactions when treated with a cephalosporin.