White to off-white crystalline powder
Antibacterial;Bacterial transpeptidase inhibitor
A semi-synthetic antibiotic related to Penicillin. Antibacterial.
Dicloxacillin sodium salt is used in the treatment of staphylococci resistant to penicillin G. Dicloxacillin binds to specific penicillin-binding proteins in the bacterial cell wall and therefore inhibits the last stage of bacterial cell wall synthesis. Cell lysis, mediated by bacterial cell wall autolytic enzymes, is the result. Dicloxacillin may interfere with autolysin inhibitors.
ChEBI: Dicloxacillin sodium monohydrate is a hydrate. It contains a dicloxacillin sodium.
A suspension of 6-aminopenicillanic acid (216 grams) in water (2 liters) was
adjusted to pH 6.8 by the addition of N aqueous sodium hydroxide
(approximately 1 liter) and the resulting solution was stirred vigorously while
a solution of 3-(2',6'-dichlorophenyl)-5-methylisoxazole-4-carbonyl chloride
(290 grams) in acetone (1.5 liters) was added in one portion.
The temperature rose to 26°C and as reaction proceeded the free acid form of
the penicillin separated as a white solid. After 30 minutes the suspension was
cooled to 10°C and stirring was continued at this temperature for 1 hour
more. The mixture was then cooled to 0°C, centrifuged, and the solid product
washed with aqueous acetone (250 ml) and finally dried in an air oven at
30°C. The product (440 grams, 94%) had [α]D20 +106.3° (c 1 in EtOH) and
was shown by alkalimetric assay to be 97.5% pure.
The salt was prepared by dissolving the free acid form of the penicillin in the
equivalent amount of aqueous sodium bicarbonate and freeze drying the
resulting solution. The hydrated salt so obtained was shown by alkalimetric
assay to be 94% pure and to contain 6% water.
The substitution of chlorine atoms on both carbons orthoto the position of attachment of the phenyl ring to the isoxazolering is presumed to enhance further the stability ofthe oxacillin congener dicloxacillin sodium, [3-(2,6-dichlorophenyl)-5-methyl-4-isoxazolyl]penicillin sodiummonohydrate (Dynapen, Pathocil, Veracillin) and toproduce high plasma concentrations of it. Its medicinalproperties and use are similar to those of cloxacillinsodium. Progressive halogen substitution, however, alsoincreases the fraction bound to protein in the plasma, potentiallyreducing the concentration of free antibiotic inplasma and tissues. Its medicinal properties and use are thesame as those of cloxacillin sodium.
Veterinary Drugs and Treatments
The veterinary use of dicloxacillin has been primarily in the PO
treatment of bone, skin, and other soft tissue infections in small
animals when penicillinase-producing Staphylococcus species have
been isolated. Because of its low oral bioavailability and short halflife,
other drugs with good staph coverage are usually employed.
