Walidix

Uses

Nalidixic acid is used for -

• Urinary tract infections caused by susceptible Gram-negative microorganisms, including the majority of Proteus strains, Klebsiella, Enterobacter spp. and E. coli.
• Gastrointestinal infections caused by Salmonella and Shigella.

Walidix is also used to associated treatment for these conditions: Urinary Tract Infection

How Walidix works

Evidence exists for Nalidixic acid that its active metabolite, hydroxynalidixic acid, binds strongly, but reversibly, to DNA, interfering with synthesis of RNA and, consequently, with protein synthesis.

Dosage

Walidix dosage

Adults:

• Initial: Oral 1 gm every 6 hours for 7 days reducing to 500 mg every 6 hours.

Infants and children 3 month of age and over:

• Initial: Oral 13.75 mg/kg body weight every six hours for one or two weeks.
• Maintenance: Oral 8.25 mg/kg body weight every six hours or as prescribed by the physician.

Should be taken with food.

Side Effects

Gastro-intestinal disturbances including nausea, vomiting, diarrhoea, haemolysis in G6PD deficiency, allergic reaction including urticaria, rashes, fever, arthralgia, eosinophilia, also myalgia, muscle weakness, phototoxicity, jaundice, visual disturbances and convulsions.

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.

Precaution

General: Should be used with caution in liver disease, epilepsy or severe cerebral arteriosclerosis patients. Periodic blood counts and renal and liver function tests should be performed if treatment is continued for more than 2 weeks. If bacterial resistance emerges, rapid change of drug should be made.

Children: Should not be used to infants less than 3 months of age.

Interaction

Concomitant use of Nalidixic acid with melphalan there have been reports of death froms severe blood containing diarrhoea caused by hemorrhagic ulcerative colitis. Probenecids inhibits tubular secretion of nalidixic acid and may therefore elevate serum concentration, possibly enhancing toxicity. Chlorpromazine and Perphenazine have been shown to potentiate the effect of Walidix in vitro.

Food Interaction

• Drink plenty of fluids.
• Take with food. Food reduces irritation.

Elimination Route

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.

Elimination Route

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.

Pregnancy & Breastfeeding use

Pregnancy: There is the possibility that it may cause cartilage damage and as it is a DNA-gyrase inhibitor there is a possibility of causing DNA damage too. Nalidixic acid is excreted in breast milk and there is a report of hemolytic anaemia in a breast feed child of an azotemic mother.

Contraindication

Walidix is contraindicated to known hypersensitivity to Nalidixic acid, history of convulsive disorders and patients with porphyria. Should be used with caution in patients with liver and renal disease. Also in glucose 6 - phosphate dehydrogenase deficiency.

Special Warning

Renal Impairment: Reduced doses should be considered.

Hepatic Impairment: Reduced doses should be considered.

Acute Overdose

Symptoms: Toxic psychosis, convulsions, increased intracranial pressure, metabolic acidosis, vomiting, nausea, lethargy.

Management: Increase fluid admin; supportive measures. Anticonvulsants may be used in severe cases.

Storage Condition

Store at room temperature, up to 25° C

Innovators Monograph

You find simplified version here Walidix