Диклоксациллин

Описание

Chemically this is 3(2,6-dichlorophenyl)-5-methyl-4-isoxazolyl penicillin. It differs from cloxacillin by having two chloride ions attached to the phenyl group. It comes as oral capsules of 250 and 500 mg, and in an injectable formulation of 500 mg and 1 g.

Использование

Antibacterial.

Определение

ChEBI: A penicillin that is 6-aminopenicillanic acid in which one of the amino hydrogens is replaced by a 3-(2,6-dichlorophenyl)-5-methyl-1,2-oxazol-4-yl]formyl group.

Антимикробная активность

It is very highly bound to serum protein, and its activity in the presence of human serum in vitro is depressed to a greater extent than that of other isoxazolylpenicillins.

Общее описание

Dicloxacillin was synthesized by Bayer in 1965 starting with 6-aminopenicillanic acid. It is a penicillinase-stable and orally active semisynthetic penicillin and shows higher and longer serum concentrations than cloxacillin when administered orally. Dicloxacillin is used orally, either alone or in combination with ampicillin, to treat various infections, including those caused by benzylpenicillin-resistant bacteria.

Фармаколо?гия

In terms of mechanism of action, antibacterial spectrum, and indications for use, it is essentially no different than oxacillin and cloxacillin. Synonyms of this drug are diclocil, novapen, diclex, and others.
The following type of semisynthetic penicillins that should be considered are those in which amino acids, mainly α-aminophenylacetic or p-oxy-α-amino-phenylacetic acids, act as the acyl radical (ampicillin, amoxacillin).
The antimicrobial spectrum of aminopenicillins is similar to penicillin G, with the exception that they also act on a number of Gram-negative microorganisms. Both aminopenicillins are destroyed by staphylococcus penicillinase.

Фармакокине?тика

Oral absorption: c. 50%
C_max , 250 mg oral: 9 mg/L after 1 h
500 mg intramuscular: 14–16 mg/L after 0.5–1 h
Plasma half-life: 0.5 h
Plasma protein binding: 95–97%
Absorption
Absorption in the very young is poor and unpredictable.
Metabolism and excretion
Dicloxacillin is partly metabolized in the liver and about 10% of the circulating drug is in the form of metabolites. Some 50–70% of a dose is excreted in the urine, about 20% as metabolites. It is eliminated both in the glomerular filtrate and by tubular secretion, and plasma concentrations are raised by probenecid. Parent drug and increased proportions of metabolites accumulate in renal failure. Elimination is increased through enhanced tubular secretion in patients with cystic fibrosis.

Побочные эффекты

Phlebitis is common after intravenous injection. Its toxicity is otherwise similar to that of other penicillins. Clinical uses are those of the group 3 penicillins.