Nalidixic Acid 300mg/5ml Oral Suspension

Nalidixic Acid BP 300mg/5ml

Suspension for oral administration

Nalidixic Acid Oral Suspension is recommended for the treatment of acute or chronic infections, especially those of the urinary tract caused by Gram-negative organisms, other than Pseudomonas species, sensitive to nalidixic acid. It may also be used for the treatment of selective cases of gastro-intestinal Gram-negative infections sensitive to nalidixic acid.

For oral administration only.

Adults including the elderly: Three 5ml spoonfuls four times daily for at least seven days reducing to two 5ml spoonfuls four times daily for chronic infections.

Children: For those over the age of three months, the recommended dose is 1ml of suspension per Kilogram body weight daily. The neonate does not tolerate nalidixic acid suspension well owing to immaturity of the liver enzymes.

Nalidixic acid is contra-indicated for patients with a history of convulsive disorder, porphyria and severe renal impairment. It should be used with caution in patients with liver disease.

Contra-indicated for those with a hypersensitivity to hydroxybenzoate esters or nalidixic acid.

Use in infants under the age of three months is not recommended.

Nalidixic acid may precipitate a haemolytic reaction in Glucose-6-phosphate dehydrogenase deficient individuals. Toxicological studies have shown that high doses of oxyquinoline antibacterial agents can produce erosion of the cartilage in weight – bearing joints in immature animals of some species. No such lesions have been reported in man to date, nevertheless, until significance of this finding is clarified, care should be exercised when prescribing nalidixic acid for children.

Prescribe with caution in patients with hepatic impairment, moderate renal impairment or severe cerebral arteriosclerosis (risk of seizures).

Monitor full blood count, renal function and hepatic function in long-term therapy (more than 2 weeks).

Although care should be exercised when treating patients with renal failure, the full dosage of nalidixic acid may be administered in patients with creatinine clearance of more than 20ml/min.

Nalidixic acid in therapeutic doses can interfere with the estimation of urinary 17-ketosteroids and may cause high results in the assay of urinary vanilmandelic acid (Pisano method).

Active proliferation of the organisms is a necessary condition for the antibacterial action of nalidixic acid and the action of the suspension may therefore be inhibited by the presence of other antibacterial substances.

When testing for glycosuria in patients receiving nalidixic acid, “Clinistix” or “Tes-tape” should be used since other reagents give a false positive result.

Patients should avoid excessive exposure to sunlight.

Discontinue treatment if symptoms of neuropathy or arthropathy occur.

Tendon damage or rupture may occur rarely. Discontinue treatment if patients experience tendon pain, inflammation or tendon rupture.

Excipient warnings

This product contains the following:

• Parahydroxybenzoates: may cause allergic reactions (possibly delayed).

• Sucrose: contains 0.45g sucrose per 5ml. This should be taken into account in patients with diabetes mellitus. Patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine. May be harmful to teeth.

• Sorbitol: patients with rare hereditary problems of fructose intolerance should not take this medicine.

• Ponceau 4R E124: may cause allergic reactions.

1. Anticoagulants (coumarin-or-indandione-derivative):

Due to competition for protein binding sites between nalidixic acid and anti-coagulants, it may be necessary to reduce the anti-coagulant dosage and monitor the prothrombin time until a satisfactory prothrombin ratio is achieved.

2. Probenecid:

May be associated with reduced efficacy against urinary pathogens and an increased incidence of side effects.

3. NSAID's:

An increased likelihood of convulsions has been reported.

4. Melphalan:

Serious GI toxicity has been reported.

5. Ciclosporin:

Increased nephrotoxicity may result.

6. Other antibacterials:

Chloramphenicol, nitrofurantoin and tetracycline may inhibit the action of nalidixic acid.

7. Oestrogens:

Theoretical risk of contraceptive failure with oestrogen containing preparations.

8. Oral typhoid vaccination:

Live vaccines can be inactivated by antibiotics.

9. Strontium ranelate, sucralfate and products containing divalent or trivalent cations such as iron, aluminium, zinc, magnesium and calcium can inhibit nalidixic acid absorption.

Nalidixic acid crosses the placenta. Particular consideration should be given before prescribing Nalidixic Acid Oral Suspension for pregnant women, especially during the first trimester. Nalidixic acid is excreted in breast milk and therefore consideration should be given when treating women who are breast feeding.

None

Blood disorders, including eosinophilia, leucopenia, thrombocytopenia, haemolytic anemia and altered prothrombin concentrations have been reported.

Metabolic acidosis has been reported.

Gastro intestinal effects including nausea, diarrhoea, abdominal pain and cholestasis have been reported. Visual disturbances may occur but are readily reversible on reduction of or discontinuation of therapy.

Skin reactions including allergic reactions (urticaria and pruritus) photosensitivity reactions (erythema, bullous eruptions) have been reported. Other reported skin reactions include Stevens Johnson syndrome, erythema multiforme, eosinophilia, angioedema and anaphylaxis.

Arthralgia, myalgia and muscular weakness. occur occasionally. Tendon damage or rupture has also been reported (discontinue treatment if tendon pain or inflammation.

Headache, dizziness, vertigo, sleep disorders, depression, hallucinations, drowsiness, confusion, excitement and disorders of taste and smell have been reported. Raised intra-cranial pressure may occur in infants. Toxic psychoses and convulsions have been reported, sometimes associated with overdosage. Patients with a post history of convulsions or cerebral arteriosclerosis are at increased risk of convulsions when taking nalidixic acid.

Reports of peripheral neuropathy, sixth cranial nerve palsy and intracranial hypertension (especially in infants/children).

In adults, symptoms of overdosage have been noted following single doses of 20g and 25g. These have included toxic psychosis convulsions and metabolic acidosis.

In an emergency, it is suggested that the stomach should be emptied and symptomatic treatment applied as necessary, a particular watch being kept for central respiratory depression.

Nalidixic acid appears to act by inhibiting DNA synthesis, probably by interfering with DNA polymerisation. Resistance may develop rapidly during treatment.

Almost all orally administered nalidixic acid is absorbed. Plasma concentrations of 20µg to 50µg may be achieved, but it is 93% to 97% bound to plasma proteins. In the body, some nalidixic acid is converted to an active hydroxynalidixic acid and both are excreted in the urine. Very high concentrations of nalidixic acid plus its active metabolite are achieved in the urine – 100µg to 500µg/ml. Antibacterial activity is not found in prostatic fluid. The plasma half life is normally about 8 hours, but it may be as long as 21 hours in the presence of renal failure.

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Propylene glycol, methyl hydroxybenzoate, propyl hydroxybenzoate, sorbic acid, sodium carboxymethylcellulose, sucrose, sorbitol solution 70%, colloidal silicon dioxide, polysorbate 80, antifoam, ponceau 4R, raspberry flavour (containing propylene glycol), strawberry flavour (containing propylene glycol), dill water and purified water.

None stated

24 months

Protect from light. Store below 25°C, avoid freezing.

Amber (type III) glass bottle with capacity of 150ml, 200ml and 500ml

Shake the bottle well before use

Rosemont Pharmaceuticals Ltd

Rosemont House

Yorkdale Industrial Park

Braithwaite Street

Leeds

LS11 9XE

PL 00427/0059

16.1.95

14^th May 2012