Calculator Logic and References
Calculator Logic
**Recommended Rx and Ranges round up to closest available dosage, using scored tablet formulations available in US market.
| Lean Body Weight(kg) | 40–55 | 56–75 | 76–90 |
|---|---|---|---|
| Daily dosing | 1000mg | 1500mg | 2000mg |
| Three times a week dosing | 1500mg | 2500mg | 3000mg |
Suggested Pyrazinamide Dosing (IF CrCl >30). Adapted from ATS/CDC/IDSA 2016 clinical practice guidelines for treatment of drug-susceptible tuberculosis.
| Lean Body Weight(kg) | 40–55 | 56–75 | 76–90 |
|---|---|---|---|
| Daily Dosing | 800mg | 1200mg | 1600mg |
| Three times weekly dosing | 1200mg | 2000mg | 2400mg |
Suggested Ethambutol Dosing (IF CrCl >30). Adapted from ATS/CDC/IDSA 2016 clinical practice guidelines for treatment of drug-susceptible tuberculosis.
Overall Dose Ranges for PZA: 18.2-26.8mg/kg(max 2000mg)
Overall Dose Ranges for EMB: 14.5-21.4mg/kg(max 1600mg)
If CrCl >30, NOT receiving renal replacement therapy, and LBW 40-90, then dosing as per
tables above.
If CrCl >30, NOT receiving renal replacement therapy, and LBW < 40 then PZA 20mg/kg and
EMB 15mg/kg
Dose Range PZA: 20-25mg/kg(max 2000mg)
Dose Range EMB: 15-20mg/kg(max 1600mg)
If CrCl < 30 OR receiving renal replacement therapy then PZA ~30mg/kg and EMB 15mg/kg with
dose frequency as described on main page
Dose Range PZA: 25-35mg/kg(max 2000mg)
Dose Range EMB: 15-25mg/kg(max 1600mg)
-
James Equation for Lean Body Mass Calculation:
- Male Lean Body Mass (kg) = (1.1 * wtKg) - 128 * (wtKg/htCm)^2
- Female Lean Body Mass (kg) = (1.07 * wtKg) - 148 * (wtKg/htCm)^2
- As described in the poster here, the James Equation arrives at a local maximum above a male BMI of 43 and female BMI of 36.
-
Cockcroft-Gault Equation
- CrCl(mL/min) = (140 – age) × (weight, kg) × (0.85 if female) / (72 × Cr)
- Dosing of PZA and EMB by weight bands in adults with normal renal function: https://www.idsociety.org/practice-guideline/treatment-of-drug-susceptible-tb/
- Dosing of PZA and EMB in adults with renal insufficiency/failure: https://www.currytbcenter.ucsf.edu/sites/default/files/tb_sg3_chap7_co-morbidities.pdf#renalfailure