Oxacillin

DOSAGE AND ADMINISTRATION

Bacteriologic studies to determine the causative organisms and their susceptibility to oxacillin should always be performed. Duration of therapy varies with the type of severity of infection as well as the overall condition of the patient, therefore it should be determined by the clinical and bacteriological response of the patient.

In severe staphylococcal infections, therapy with oxacillin should be continued for at least 14 days. Therapy should be continued for at least 48 hours after the patient has become afebrile, asymptomatic, and cultures are negative. Treatment of endocarditis and osteomyelitis may require a longer duration of therapy.

With intravenous administration, particularly in elderly patients, care should be taken because of the possibility of thrombophlebitis. RECOMMENDED DOSAGES FOR OXACILLIN FOR INJECTION, USP Drug Adults Infants and Children < 40 kg ( 88 lbs ) Other Recommendations Oxacillin 250 to 500 mg IM or IV every 4 to 6 hours (mild to moderate infections) 50 mg/kg/day IM or IV in equally divided doses every 6 hours (mild to moderate infections) 1 gram IM or IV every 4 to 6 hours (severe infections) 100 mg/kg/day IM or IV in equally divided doses every 4 to 6 hours (severe infections) Premature and Neonates 25 mg/kg/day IM or IV Directions for use For Intramuscular Use: Use Sterile Water for Injection, USP.

6 mL to the 2 gram vial. Shake well until a clear solution is obtained. 5 mL of solution. The reconstituted solution is stable for 3 days at 70° F or for one week under refrigeration (40° F).

For Direct Intravenous Use:

Use Sterile Water for Injection, USP or Sodium Chloride Injection, USP. Add 10 mL to the 1 gram vial and 20 mL to the 2 gram vial. Withdraw the entire contents and administer slowly over a period of approximately 10 minutes.

For Administration by Intravenous Drip:

Reconstitute as directed above ( For Direct Intravenous Use ) prior to diluting with Intravenous Solution. STABILITY PERIODS FOR OXACILLIN FOR INJECTION, USP Concentration mg / mL Sterile Water for Injection , USP 0 . 9 % Sodium Chloride Injection , USP M / 6 Molar Sodium Lactate Solution 5 % Dextrose in water 5 % Dextrose in 0 .

ADVERSE REACTIONS

7 to 10 percent (see WARNINGS ). Sensitization is usually the result of treatment but some individuals have had immediate reactions when first treated. In such cases, it is thought that the patients may have had prior exposure to the drug via trace amounts present in milk and vaccines.

Two types of allergic reactions to penicillins are noted clinically, immediate and delayed. Immediate reactions usually occur within 20 minutes of administration and range in severity from urticaria and pruritus to angioneurotic edema, laryngospasm, bronchospasm, hypotension, vascular collapse, and death.

Such immediate anaphylactic reactions are very rare (see WARNINGS ) and usually occur after parenteral therapy but have occurred in patients receiving oral therapy. Another type of immediate reaction, an accelerated reaction, may occur between 20 minutes and 48 hours after administration and may include urticaria, pruritus, and fever.

Although laryngeal edema, laryngospasm, and hypotension occasionally occur, fatality is uncommon. Delayed allergic reactions to penicillin therapy usually occur after 48 hours and sometimes as late as 2 to 4 weeks after initiation of therapy.

e, fever, malaise, urticaria, myalgia, arthralgia, abdominal pain) and various skin rashes. Nausea, vomiting, diarrhea, stomatitis, black or hairy tongue, and other symptoms of gastrointestinal irritation may occur, especially during oral penicillin therapy.

Nervous System Reactions Neurotoxic reactions similar to those observed with penicillin G may occur with large intravenous doses of oxacillin especially with patients with renal insufficiency. Urogenital Reactions Renal tubular damage and interstitial nephritis have been associated with the administration of oxacillin.

WARNINGS

Serious and occasionally fatal hypersensitivity (anaphylactic shock with collapse) reactions have occurred in patients receiving penicillin. 04 percent. 002 percent of the patients treated. When oxacillin therapy is indicated, it should be initiated only after a comprehensive patient drug and allergy history has been obtained.

If an allergic reaction occurs, oxacillin should be discontinued and appropriate therapy instituted. Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including oxacillin for injection, USP, and may range in severity from mild diarrhea to fatal colitis.

Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile . C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy.

CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.

If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile , and surgical evaluation should be instituted as clinically indicated.

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