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.
Side 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).
Mode 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.