Nalidixic acid

Reduced doses should be considered.

Reduced doses should be considered.

Should be taken with food.

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

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.

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).

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.

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.

May cause false-positive urinary glucose tests using copper reduction methods. May also interfere with 17-ketosteroids and ketogenic steroids determinations.

Description:
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.
Pharmacokinetics:
Absorption: Rapidly and almost completely absorbed from the GI tract. (oral); peak plasma concentrations after 1-2 hr (oral).
Distribution: Crosses the placenta; enters the breast milk. Protein-binding: 93% (nalidixic acid); 63% (hydroxynalidixic acid).
Metabolism: Partially converted in the liver to hydroxynalidixic acid.
Excretion: Via urine (80-90% as inactive metabolites); faeces (4%); 1-2.5 hr (elimination half-life).

Store at room temperature, up to 25°C (77°F).

Quinolon