ZINAMIDE Tablet Ref.[8534] Active ingredients: Pyrazinamide

‘Zinamide’ should only be used when close daily observation of the patient is possible, and when laboratory facilities are available for performing frequent liver-function tests and blood uric acid determinations.

Pre-treatment examinations should include in-vitro sensitivity tests of recent cultures of M. tuberculosis from the patient as measured against the usual antituberculous drugs. Side effects for ‘Zinamide’ primarily involve the liver and vary from asymptomatic elevations of liver function tests to serious clinical manifestations of hepatic disease; therefore, liver-function tests, especially aspartate transferase (AST) and alanine transferase (ALT) determinations, should be carried out prior to therapy, and then every two to four weeks during therapy. Therapy with ‘Zinamide’ should be withdrawn and not reinstated if signs of hepatocellular damage occur.

Patients or their carers should be told how to recognize signs of liver disease, and advised to discontinue treatment and seek immediate medical attention if symptoms such as persistent nausea, vomiting, malaise or jaundice develop.

Reduction in the size and/or frequency of dose is recommended for patients with renal insufficiency.

Pre-treatment examinations should include renal function, hepatic function and particularly base-line uric acid determinations. Pyrazinamide inhibits excretion of urates, frequently resulting in hyperuricaemia which is usually asymptomatic. If hyperuricaemia accompanied by an acute gouty arthritis occurs, therapy should be discontinued and not reinstated. Close monitoring is advised to detect any increasing difficulty in the management of patients with a history of gout or diabetes mellitus.

Zinamide should be used with caution in pregnant women.

Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Pyrazinamide antagonizes the effect of uricosuric agents such as probenecid and sulfinpyrazone. Pyrazinamide may reduce the contraceptive effects of oestrogens and should be avoided 3 days before and after oral typhoid vaccination since it may inactivate the vaccine.

Pregnancy

There have been no well-controlled studies in pregnant women. ‘Zinamide’ should only be used if the potential benefit justifies the risk to the foetus.

Lactation

‘Zinamide’ is contra-indicated in breast-feeding mothers. If its use is deemed essential, the patient should stop breast-feeding.

There are no data to suggest that ‘Zinamide’ affects the ability to drive or use machines.

A hepatic reaction is the most common side effect of ‘Zinamide’ and may occur at any time during therapy. This varies from a symptomless abnormality of hepatic cell function, detectable only by laboratory tests, through a mild syndrome of fever, anorexia, malaise, liver tenderness, hepatomegaly and spleenomegaly, to more serious reactions such as clinical jaundice, and rare cases of hepatic failure and death.

Other side effects-active gout, sideroblastic anaemia, arthralgias, anorexia, nausea and vomiting, flushing, dysuria, malaise, fever, rash, hypersensitivity reactions such as urticaria and pruritus, aggravation of peptic ulcer and occasionally photosensitivity.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.

None known.