Pyrazinamide Dosing for Disseminated TB

Weight-Based Dosing Calculation

For a patient weighing 74 kg, the American Academy of Family Physicians and the American Thoracic Society recommend administering pyrazinamide 2,000 mg once daily for the initial 2 months of treatment as part of a multi-drug regimen 1, 2
A patient weighing 74 kg falls into the 56-75 kg weight band, but since they are close to the 76 kg threshold, the higher dose of 2,000 mg daily is recommended to ensure adequate drug exposure 1, 2

The CDC recommends that pyrazinamide dosing should be based on lean body weight, with 2,000 mg being the maximum daily dose regardless of weight 1, 2

Pyrazinamide must always be administered with other effective antituberculosis drugs, typically in combination with isoniazid, rifampin, and ethambutol, as recommended by the American Academy of Family Physicians and the American Thoracic Society 1, 2

For twice-weekly directly observed therapy (DOT), the dose would be 3,000 mg for the 56-75 kg weight band, as recommended by the American Academy of Family Physicians and the American Thoracic Society 1, 2
Daily dosing is preferred over intermittent dosing for HIV-infected patients with low CD4 counts due to higher rates of treatment failure with twice-weekly regimens, according to the American Thoracic Society 2

Baseline liver function tests should be obtained, with regular monitoring required for patients with known chronic liver disease, as recommended by the British Thoracic Society 3
If liver function tests rise to 5 times normal or bilirubin rises, pyrazinamide should be stopped immediately, according to the British Thoracic Society 3

Patients at the upper end of a weight band should receive the higher dose to ensure adequate exposure, as recommended by the American Academy of Family Physicians and the American Thoracic Society 1, 2
Do not continue pyrazinamide beyond 2 months in drug-susceptible TB, even if extending total treatment duration, as recommended by the American Academy of Family Physicians 1
Do not use fixed-dose combination tablets for patients weighing >90 kg without adding additional pyrazinamide tablets, as recommended by the American Thoracic Society 2, 4

The American Academy of Family Physicians recommends pyrazinamide dosing at 15-30 mg/kg daily (maximum 2 g/day) for the initial 2 months of treatment, with weight-banded dosing of 1,000 mg for 40-55 kg, 1,500 mg for 56-75 kg, and 2,000 mg for 76-90 kg patients 5, 6
For adults weighing 40-55 kg, the recommended daily dose is 1,000 mg (18.2-25.0 mg/kg) 5
For adults weighing 56-75 kg, the recommended daily dose is 1,500 mg (20.0-26.8 mg/kg) 5
For adults weighing 76-90 kg, the recommended daily dose is 2,000 mg (22.2-26.3 mg/kg) 5

For twice-weekly dosing, the recommended dose is 2,000 mg (36.4-50.0 mg/kg) for 40-55 kg, 3,000 mg (40.0-53.6 mg/kg) for 56-75 kg, and 4,000 mg (44.4-52.6 mg/kg) for 76-90 kg 5
For thrice-weekly dosing, the recommended dose is 1,500 mg (27.3-37.5 mg/kg) for 40-55 kg, 2,500 mg (33.3-44.6 mg/kg) for 56-75 kg, and 3,000 mg (33.3-39.5 mg/kg) for 76-90 kg 5

The American Journal of Respiratory and Critical Care Medicine recommends daily dosing of 15-30 mg/kg once daily (maximum 2 g) for pediatric patients 6
The American Journal of Respiratory and Critical Care Medicine recommends twice-weekly dosing of 50-70 mg/kg (maximum 4 g) for pediatric patients 6

The European Respiratory Journal recommends pyrazinamide administration for the initial 2 months only of a 6-month treatment regimen for drug-susceptible tuberculosis 7
For patients with cavitation on initial chest radiograph and positive cultures at 2 months, the continuation phase should be extended to 7 months (total 9 months), but pyrazinamide is still only given for the first 2 months 5

The European Respiratory Journal recommends using the same dosing as HIV-negative patients for HIV-coinfected patients 7
The MMWR Recommendations and Reports suggest that rifabutin-based regimens may be necessary when using protease inhibitors or NNRTIs in HIV-coinfected patients 8

The American Academy of Family Physicians recommends monitoring all patients monthly for adherence and adverse effects 5
The Thorax journal recommends baseline and regular liver function monitoring in patients with chronic liver disease 9