Nalidixic Acid

Indications

Nalidixic Acid is used for: Lower urinary tract infections, Shigellosis

Adult Dose

Oral Uncomplicated lower urinary tract infections Adult: 1 g 4 times daily for 1-2 wk. Long-term therapy: Reduce daily dose to 2 g. Shigellosis Adult: 1 g 4 times daily for 5 days. Hepatic impairment: Reduced doses should be considered.

Child Dose

Oral Uncomplicated lower urinary tract infections Child: >3 mth: 50 mg/kg daily in 4 equally divided doses. Long-term therapy: Reduce dose to 30 mg/kg daily. Prophylaxis: 15 mg/kg bid. Shigellosis Child: >3 mth: 15 mg/kg 4 times daily for 5 days.

Renal Dose

Renal impairment: Reduced doses should be considered.

Administration

Should be taken with food.

Contra Indications

Hypersensitivity. History of convulsive disorders or porphyria. Infants <3 mth. Severe renal impairment.

Precautions

Hepatic or moderate renal impairment, severe cerebral arteriosclerosis, G6PD deficiency. Monitor blood counts, renal and hepatic function for treatment >2 wk. Children <18 yr. Elderly. Avoid exposure to sunlight or sunlamps. Pregnancy and lactation.

Pregnancy-Lactation

Interactions

Absorption reduced by sucralfate, and divalent and trivalent cations e.g. aluminium, calcium, iron, magnesium, zinc. Excretion reduced and plasma concentrations increased with probenecid. Reduced effects with chloramphenicol, nitrofurantoin, tetracycline. Potentially Fatal: Fatal haemorrhagic enterocolitis may occur when used with high-dose melphalan in children. Increased risk of nephrotoxicity with ciclosporin. May increase effects of oral anticoagulants e.g. warfarin.

Adverse Effects

Side effects of Nalidixic Acid : Nausea, vomiting, diarrhoea, abdominal pain; photosensitivity reactions, allergic rash, urticaria, pruritus; visual disturbances, headache, dizziness or vertigo, drowsiness, confusion, depression, excitement, hallucinations, toxic psychoses or convulsions (especially after large doses), intracranial hypertension (especially in infants and young children), metabolic acidosis; peripheral neuropathies, muscular weakness, myalgia; arthralgia, tendon damage; cholestatic jaundice, thrombocytopenia, leucopenia. Potentially Fatal: Erythema multiforme and Stevens-Johnson syndrome; anaphylactoid reactions. Auto-immune haemolytic anaemia (particularly in elderly patients).

Mechanism of Action

Nalidixic acid is a 4-quinolone antibacterial. It interferes with the replication of bacterial DNA by inhibiting DNA gyrase activity. It acts against gram-negative bacteria including E. coli, Proteus, Klebsiella, Enterobacter, Salmonella and Shigella spp.