Pyrazinamide Dosing for 65kg Patient
For a patient weighing 65kg, administer pyrazinamide 1,500 mg once daily for the initial 2 months of tuberculosis treatment. 1, 2, 3
Weight-Based Dosing Rationale
A 65kg patient falls into the 56-75kg weight band, for which the recommended daily dose is 1,500 mg (delivering 20.0-26.8 mg/kg), according to the ATS/CDC/ERS/IDSA guidelines 1, 2
The FDA label specifies pyrazinamide dosing at 15-30 mg/kg once daily, with a maximum of 2g per day for daily regimens 3
At 1,500 mg daily, this 65kg patient receives approximately 23 mg/kg, which falls appropriately within the recommended range and achieves target exposures 1, 2
Administration Guidelines
Pyrazinamide must always be administered with other effective antituberculous drugs (typically rifampin, isoniazid, and ethambutol) as part of a multi-drug regimen 3, 2
Administer for the initial 2 months only of a 6-month treatment regimen for drug-susceptible tuberculosis, even if total treatment duration is extended 2, 3
Once-daily dosing is preferred over divided doses, as most current recommendations support single daily administration 3
Alternative Dosing Schedules (if applicable)
For twice-weekly directly observed therapy (DOT): 3,000 mg (40.0-53.6 mg/kg) for the 56-75kg weight band 1, 2
For thrice-weekly dosing: 2,500 mg (33.3-44.6 mg/kg) for the 56-75kg weight band 2
Daily dosing is strongly preferred over intermittent dosing for HIV-infected patients with low CD4 counts due to higher treatment failure rates with twice-weekly regimens 2
Critical Monitoring Requirements
Obtain baseline liver function tests before initiating therapy 2
Monitor monthly for adherence and adverse effects, including hepatotoxicity and arthralgia 2
If liver function tests rise to 5 times normal or bilirubin rises, stop pyrazinamide immediately 2
Regular monitoring is especially important in patients with chronic liver disease, alcoholism, or hepatitis B/C positivity 1
Common Pitfalls to Avoid
Do not use weight-banded dosing tables for patients >90kg without adding supplemental pyrazinamide tablets when using fixed-dose combinations 2
Do not continue pyrazinamide beyond 2 months in drug-susceptible TB, even if extending total treatment duration to 9 months for cavitary disease 2
Do not underdose patients at the upper end of weight bands - recent pharmacokinetic data suggests flat dosing may be superior to weight-banded approaches, though current guidelines still recommend weight bands 4, 5
Special Populations
Renal impairment: For patients with creatinine clearance <10 mL/min, use 50-100% of the full dose once daily, or administer 25-30 mg/kg after hemodialysis 1
HIV coinfection: Use the same dosing as HIV-negative patients, but be aware that rifabutin-based regimens may be necessary with certain antiretroviral medications 2
Hepatic disease: Baseline and regular liver function monitoring is required, though pyrazinamide can be used cautiously with surveillance 1