PYRAZINAMIDE

5g daily. Patients ≥ 50kg and over bodyweight: maximum of 4 tablets or 2g daily. Children: 35mg/kg daily.

Recommended dosage for intermittent supervised 2-month treatment:

Adults: Under 50kg bodyweight: maximum of 4 tablets or 2g 3 times a week. 5g 3 times a week. Children: 50mg/kg 3 times a week. ‘Pyrazinamide’ should be administered with at least one other effective antituberculous drug. The use of ‘Pyrazinamide’ in combination therapy does not modify the accepted dosages of other antituberculous agents.

Use in elderly:

The general considerations outlined above should also apply to elderly patients.

Immunocompromised patients:

Multi-resistant M. tuberculosis may be present in immunocompromised patients. The organism should always be cultured to confirm its type and drug sensitivity. Confirmed M. Tuberculosis infection sensitive to first-line drugs should be treated with a standard 6 month regimen; after completing treatment, patients should be closely monitored.

The regimen may need to be modified if infection is caused by resistant organisms and specialist advice is needed. In meningeal or pericardial tuberculosis, a corticosteroid should be started at the same time as antituberculosis therapy.

A hepatic reaction is the most common side effect of ‘Pyrazinamide’ 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. uk/yellowcard or search for MHRA Yellow Card in the Google play or Apple App Store.

‘Pyrazinamide’ 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 ‘Pyrazinamide’ 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 ‘Pyrazinamide’ 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.

‘Pyrazinamide’ should be used with caution in pregnant women.

‘Pyrazinamide’ is contra-indicated in patients with: • hypersensitivity to pyrazinamide or to any of the excipients • hepatic disease • hyperuricaemia and/or gouty arthritis • acute porphyria. 6 Pregnancy and lactation).