From the Guidelines
Rifampicin (RIF) will not require dose adjustment due to impaired renal function.
Reasons for this choice
- RIF is metabolized by the liver, so conventional dosing may be used in the setting of renal insufficiency 1.
- RIF is not cleared by hemodialysis because of its high molecular weight, wide distribution into tissues, high degree of protein binding, and rapid hepatic metabolism 1.
Other relevant information
- Other drugs such as INH are also metabolized by the liver and do not require dose adjustment in renal insufficiency 1.
- However, Ethionamide is also not cleared by the kidneys, nor is the drug removed with hemodialysis, so no dose adjustment is necessary 1.
- In contrast, drugs like PZA, EMB, Streptomycin, Kanamycin, Amikacin, Capreomycin, and Cycloserine require dose adjustment in patients with renal insufficiency due to their renal clearance 1.
From the Research
Drug Dosage Adjustment in Tuberculosis Treatment
The treatment of Tuberculosis (TB) involves the use of multiple drugs, and dosage adjustment is crucial in patients with impaired renal function. The following points highlight the key considerations:
- Dosage adjustment of anti-TB drugs is recommended according to renal function for patients with chronic kidney disease (CKD) 2.
- The efficacy and safety outcomes of renal function-based dosage adjustments are not fully elucidated, but studies suggest that adjusting the dosage of TB treatment for CKD patients according to guidelines can be efficient in terms of similar therapeutic outcomes to those of the non-CKD group 2.
- However, adverse events (AEs) warrant attention to avoid regimen change in patients with severe CKD, even if the renal function-based dosage adjustment is performed 2.
- The first-line drugs for TB treatment include isoniazid, rifampin, pyrazinamide, and ethambutol, and the dosage adjustment for these drugs is crucial in patients with impaired renal function 3, 4, 5.
- Among these drugs, ethambutol is the one that does not require dose adjustment due to impaired renal function, as it is primarily excreted through the kidneys, but its dosage adjustment is not as critical as the other drugs 3, 4, 5.
Key Considerations for Drug Dosage Adjustment
The following points highlight the key considerations for drug dosage adjustment in TB treatment:
- Isoniazid, rifampin, and pyrazinamide require dose adjustment in patients with impaired renal function 3, 4, 5.
- Ethambutol does not require dose adjustment due to impaired renal function, but its use should be monitored closely in patients with severe CKD 3, 4, 5.
- The dosage adjustment of anti-TB drugs should be based on the patient's renal function, and the guidelines recommend adjusting the dosage according to the severity of CKD 2.