Update: January 2022
12.1 Normal values for creatinine clearance (CrCl)
Women: 88 to 128 ml/minute
Men: 97 to 137 ml/minute
12.2 Estimation of CrCl (Cockcroft-Gault method)
12.2.1 If serum creatinine is in µmol/litre
Weight (kg) x (140 – age) x (constant)
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Serum creatinine (µmol/litre)
The constant = 1.04 for women and 1.23 for men
12.2.2 If serum creatinine is in mg/dl
Weight (kg) x (140 – age)
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72 x serum creatinine (mg/dl)
For women, the result must be multiplied by 0.85.
Example (calculation with serum creatinine in µmol/litre)
a
Citation
a.
If possible use a calculator to avoid errors, e.g.:
https://www.mdcalc.com/creatinine-clearance-cockcroft-gault-equation
:
A woman on cycloserine (Cs), 50 kg, 46 years, serum creatinine = 212 µmol/litre
- Step 1 - Calculate the CrCl:
50 x (140 – 46) x 1.04 = 4,888
4,888 ÷ 212 = 23.1
For this patient, the CrCl is 23.1 ml/minute - Step 2 - CrCl is < 30 ml/minute, administer 250 mg of Cs once daily or 500 mg 3 times a week.
- Step 3 - Adjust each drug as required according to the table below.
12.2.3 Overweight and obese patients
For overweight (BMI > 25) or obese (BMI > 30) patients, use the ideal body weight (IBW) rather than the actual body weight to avoid overestimation of the CrCl.
The IBW is calculated using the patient’s height
b
Citation
b.
If possible use a calculator to avoid errors, e.g.:
https://www.mdcalc.com/ideal-body-weight-adjusted-body-weight
:
IBW women (kg) = 45.4 + 0.89 (height in cm – 152.4)
IBW men (kg) = 49.9 + 0.89 (height in cm – 152.4)
Example:
A woman, weight 70 kg, height 160 cm (BMI = 27.3, i.e. overweight)
45.4 + 0.89 (160 – 152.4) = 45.4 + 0.89 (7.6) = 45.4 + 6.76 = 52.2
For this patient, the IBW is 52 kg.
12.3 Dosing of TB drugs in renal insufficiency
|
Drugs |
Dose and frequency if CrCl < 30 ml/min |
|---|---|
|
H |
No change |
|
R |
No change |
|
Z |
25 mg/kg 3 times a week (not daily) |
|
E |
15-25 mg/kg 3 times a week (not daily) |
|
Rfb |
No change |
|
Mfx |
No change |
|
Lfx |
750-1000 mg 3 times a week (not daily) |
|
Bdq (a) Citation a. Use with caution in case of severe renal insufficiency or dialysis (limited data). |
No change |
|
Lzd |
No change |
|
Cfz |
No change |
|
Cs (b) Citation b. Monitor carefully for signs of neurotoxicity. |
250 mg once daily or 500 mg 3 times a week |
|
Dlm (a) Citation a. Use with caution in case of severe renal insufficiency or dialysis (limited data). |
No change |
|
Ipm/Cln |
750 mg every 12 hours for CrCl 20-40 ml/min |
|
Mpm |
750 mg every 12 hours for CrCl 20-40 ml/min |
|
Am (c) Citation c. Use with caution in case of severe renal insufficiency or dialysis (increased risk of nephrotoxicity and ototoxicity). |
12-15 mg/kg 2 or 3 times a week (not daily) |
|
S (c) Citation c. Use with caution in case of severe renal insufficiency or dialysis (increased risk of nephrotoxicity and ototoxicity). |
12-15 mg/kg 2 or 3 times a week (not daily) |
|
Eto/Pto |
No change |
|
PAS (d) Citation d. Avoid sodium salt formulations of PAS in patients with severe renal disease (risk of excessive sodium load). |
4 g 2 times daily |
|
Hh |
No information |
|
Amx/Clv (e) Citation e. On a case-by-case basis, consider once daily dosing (e.g. 500/125 mg every 24 hours) for patients with CrCl < 10 ml/minute. |
No change |
|
P |
No change |
|
Pa |
No information |
- (a)If possible use a calculator to avoid errors, e.g.:
https://www.mdcalc.com/creatinine-clearance-cockcroft-gault-equation - (b)If possible use a calculator to avoid errors, e.g.:
https://www.mdcalc.com/ideal-body-weight-adjusted-body-weight
- (a) Use with caution in case of severe renal insufficiency or dialysis (limited data).
- (b)Monitor carefully for signs of neurotoxicity.
- (c) Use with caution in case of severe renal insufficiency or dialysis (increased risk of nephrotoxicity and ototoxicity).
- (d)Avoid sodium salt formulations of PAS in patients with severe renal disease (risk of excessive sodium load).
- (e)On a case-by-case basis, consider once daily dosing (e.g. 500/125 mg every 24 hours) for patients with CrCl < 10 ml/minute.