Nalidixic acid
Nalidixic acid (NegGram)
Nalidixic acid
(nah-lih- DICKS-ick AH-sid)
Pregnancy Category: B NegGram (Rx)

Classification: Urinary germicide

Action/Kinetics: Thought to inhibit the DNA synthesis, probably by interfering with DNA polymerization. Is either bacteriostatic or bactericidal. Rapidly absorbed from the GI tract. Peak plasma concentration: 20-40 mcg/mL after 1-2 hr; peak urine levels: 150-200 mcg/mL after 3-4 hr. t 1/2, plasma: 1.5 hr (increased to 21 hr in anuric clients); t 1/2, urine: 6 hr. Metabolized in the liver to hydroxynalidixic acid (comparable activity to nalidixic acid) and inactive compounds which are rapidly excreted. Extensively protein bound.
Sensitivity determinations are recommended before and periodically during prolonged administration of nalidixic acid. Renal and liver function tests are advisable if course of therapy exceeds 2 weeks.

Uses: Acute and chronic UTIs caused by susceptible gram-negative organisms, including Escherichia coli, Proteus, Enterobacter and Klebsiella.

Contraindications: Lactation. Use in infants less than 3 months of age.

Special Concerns: Use with caution in prepubertal children, clients with liver disease, severely impaired kidney function, epilepsy, and severe cerebral arteriosclerosis.

Side Effects: GI: N&V;, diarrhea, abdominal pain. CNS: Drowsiness, headache, dizziness, weakness, vertigo, toxic psychoses, intracranial hypertension, seizures (rare). Also, increased intracranial pressure with bulging anterior fontanel, papilledema, and headache; sixth cranial nerve palsy in children and infants. Allergic: Photosensitivity (e.g., erythema, painful bullae on exposed skin), skin rashes, arthralgia (joint swelling and stiffness), pruritus, urticaria, angioedema, eosinophilia, anaphylaxis (rare). Hematologic: Leukopenia, thrombocytopenia, hemolytic anemia (especially in clients with G6PD deficiency). Ophthalmic: Reversible subjective visual disturbances, including overbrightness of lights, difficulty in focusing, changes in color perception, double vision, decreased visual acuity. Other: Metabolic acidosis, cholestatic jaundice, cholestasis, paresthesia.

Laboratory Test Alterations: False + for urinary glucose with Benedict's solution, Fehling's solution, or Clinitest Reagent tablets. Falsely elevated 17-ketosteroids.

Overdose Management: Symptoms: Toxic psychoses, convulsions, increased intracranial pressure, nausea, vomiting, lethargy, metabolic acidosis. Treatment: Gastric lavage if the overdose is identified early. If absorption has occurred, fluid administration is increased with supportive measures. In severe cases, use of anticonvulsants may be necessary.

Drug Interactions: Antacids, oral / Nalidixic acid effect R/T GI tract absorption Anticoagulants, oral / Anticoagulant effect R/T plasma protein binding Nitrofurantoin / Effect of nalidixic acid

How Supplied: Suspension: 250 mg/5 mL; Tablet: 250 mg, 500 mg, 1 g

Dosage
?Oral Suspension, Tablets
Adults: initially, 1 g q.i.d. for 1-2 weeks; maintenance, if necessary, 0.5 g q 6 hr. Maximum daily dose: 4 g. Children, 3 months to 12 years, initial: 55 mg/kg/day in four equally divided doses; maintenance: 33 mg/kg/day.