Drug Groups

approved

Description

A synthetic 1,8-naphthyridine antimicrobial agent with a limited bacteriocidal spectrum. It is an inhibitor of the A subunit of bacterial DNA gyrase. [PubChem]

Indication

For the treatment of urinary tract infections caused by susceptible gram-negative microorganisms, including the majority of E. Coli, Enterobacter species, Klebsiella species, and Proteus species.

Pharmacology

Nalidixic acid is a quinolone antibacterial agent for oral administration. Nalidixic acid has marked antibacterial activity against gram-negative bacteria including Enterobacter species, Escherichia coli, Morganella Morganii; Proteus Mirabilis, Proteus vulgaris, and Providencia rettgeri. Pseudomonas species are generally resistant to the drug. Nalidixic acid is bactericidal and is effective over the entire urinary pH range. Conventional chromosomal resistance to nalidixic acid taken in full dosage has been reported to emerge in approximately 2 to 14 percent of patients during treatment; however, bacterial resistance to nalidixic acid has not been shown to be transferable via R factor.

Toxicity

ORAL (LD₅₀): Acute: 1160 mg/kg [Rat]. 572 mg/kg [Mouse]. Toxic psychosis, convulsions, increased intracranial pressure, or metabolic acidosis may occur in patients taking more than the recommended dosage. Vomiting, nausea, and lethargy may also occur following overdosage.

Affected Organisms

Biotransformation

Hepatic. 30% of administered dose is metabolized to the active metabolite, hydroxynalidixic acid. Rapid conjugation of parent drug and active metabolite to inactive metabolites. Metabolism may vary widely among individuals. In the urine, hydroxynalidixic acid represents 80 to 85% of the antibacterial activity.

Absorption

Following oral administration, nalidixic acid is rapidly absorbed from the gastrointestinal tract. Bioavailability is approximately 96%. Absorption may be delayed if taken with antacids.

Half Life

1.1 to 2.5 hours in healthy adult patients, and up to 21 hours in patients with impaired renal function.

Protein Binding

Nalidixic acid is 93% bound to protein in the blood, and the active metabolite, hydroxynalidixic acid is 63% bound.

Elimination

Following oral administration, NegGram is rapidly absorbed from the gastrointestinal tract, partially metabolized in the liver, and rapidly excreted through the kidneys.
Approximately four percent of NegGram is excreted in the feces.

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