Dicloxacillin - How It Works

CLINICAL PHARMACOLOGY Microbiology Mechanism of Action 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.

Absorption of dicloxacillin sodium after oral administration is rapid but incomplete; peak blood levels are achieved in 1 to 1.5 hours.

In one study, after ingestion of a single 500 mg oral dose, peak serum concentrations range from 10 to 17 mcg/mL for dicloxacillin.

Oral absorption of dicloxacillin is delayed when the drugs are administered after meals.

Once absorbed, dicloxacillin sodium is 97.9 ± 0.6 percent bound to serum protein, mainly albumin.

Dicloxacillin sodium vary in the extent to which they are distributed in the body fluids.

With normal doses, insignificant concentrations are found in the cerebrospinal fluid and aqueous humor.

Dicloxacillin sodium is found in therapeutic concentrations in the pleural, bile and amniotic fluids.

Dicloxacillin sodiumis rapidly excreted, primarily as unchanged drug in the urine by glomerular filtration and active tubular secretion.

The elimination half-life for dicloxacillin is about 0.7 hour.

Nonrenal elimination includes hepatic inactivation and excretion in bile.

Dicloxacillin is not dialyzable.

Only minimal amounts are removed by hemodialysis or peritoneal dialysis.