Dicloxacillin

To reduce the development of drug-resistant bacteria and maintain the effectiveness of dicloxacillin sodium capsules and other antibacterial drugs, dicloxacillin sodium capsules 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. Dicloxacillin sodium capsules are indicated in the treatment of infections caused by penicillinase-producing staphylococci which have demonstrated susceptibility to the drug. Cultures and susceptibility tests should be performed initially to determine the causative organisms and their sensitivity to the drug.

Penicillinase-resistant penicillins exert a bactericidal action against penicillin-susceptible microorganisms during the state of active multiplication. All penicillins inhibit the biosynthesis of the bacterial cell wall. Antibacterial Activity Dicloxacillin sodium has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section. Gram-positive Bacteria Staphylococcus spp. Susceptibility Testing For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC. Pharmacokinetics Dicloxacillin sodium is resistant to destruction by acid.

Concurrent administration of the penicillinase-resistant penicillins and probenecid increases and prolongs serum penicillin levels. Probenecid decreases the apparent volume of distribution and slows the rate of excretion by competitively inhibiting renal tubular secretion of penicillin. Penicillin-probenecid therapy is generally limited to those infections where very high serum levels of penicillin are necessary. Oral preparations of the penicillinase-resistant penicillins should not be used as initial therapy in serious, life-threatening infections. Oral therapy with the penicillinase-resistant penicillins may be used to follow up the previous use of a parenteral agent as soon as the clinical condition warrants. RECOMMENDED DOSAGES FOR DICLOXACILLIN SODIUM IN MILD TO MODERATE AND SEVERE INFECTIONS 1.

Dicloxacillin sodium capsules are contraindicated in persons who have shown hypersensitivity to any of the penicillins or any component of the formulations.

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%. Anaphylactic shock resulting in death has occurred in approximately 0.002% 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, dicloxacillin should be discontinued and appropriate therapy instituted. Individuals with a history of penicillin hypersensitivity may also experience allergic reactions when treated with a cephalosporin.

Hypersensitive Reactions The reported incidence of allergic reactions to penicillin ranges from 0.7% to 10%. Sensitization is usually the result of treatment, but some individuals have had immediate reactions to penicillin 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 penicillin 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 and usually occur after parenteral therapy, but have occurred in patients receiving oral therapy.

Tetracycline, a bacteriostatic antibiotic, may antagonize the bactericidal effect of penicillin and concurrent use of these drugs should be avoided. Probenecid administered concomitantly with penicillins increases and prolongs serum penicillin levels. Penicillinase-resistant penicillins, like other penicillins, are physically and/or chemically incompatible with aminoglycosides and can inactivate the drugs in vitro. In vitro mixing of penicillins and aminoglycosides should be avoided during concomitant therapy and the drugs should be administered separately. Penicillins can inactivate aminoglycosides in vitro in serum samples from patients receiving both drugs, which could produce falsely decreased results in serum aminoglycoside assays of the serum samples. Dicloxacillin may reduce the anticoagulant response to dicumarol and warfarin.

Store at 20° to 25°C (68° to 77°F), excursions permitted to 15° to 30°C (59° to 86°F).