From the Guidelines
Both Rifampicin and Isoniazid do not require dose adjustment in patients with Impaired Renal Function.
Key Points
- Rifampicin and Isoniazid are metabolized by the liver, so conventional dosing may be used in the setting of renal insufficiency 1.
- The liver metabolism of these drugs means that their clearance is not significantly affected by renal function, allowing for standard dosing in patients with impaired renal function.
- In contrast, other antituberculosis medications such as pyrazinamide, ethambutol, and streptomycin require dose adjustments in patients with renal insufficiency due to their renal clearance 1.
- It is essential to note that while Rifampicin and Isoniazid do not require dose adjustment, monitoring of serum concentrations may be necessary to avoid toxicity in patients with severe renal impairment 1.
From the FDA Drug Label
Serum concentrations do not differ in patients with renal failure at a studied dose of 300 mg, and consequently, no dosage adjustment is required.
Rifampicin does not require dose adjustment in patients with Impaired Renal Function. 2
From the Research
Treatment of Tuberculosis with Impaired Renal Function
- The provided studies do not directly address the question of which drug, Rifampicin or Isoniazid, does not require dose adjustment in patients with impaired renal function.
- However, the studies suggest that both Rifampicin and Isoniazid can cause adverse renal effects, including nephrotoxicity and acute renal failure 3, 4, 5, 6.
- Rifampicin has been associated with nephrotoxicity, sometimes resulting in acute renal failure with oligoanuria, and hepatotoxicity 3, 4.
- Isoniazid has been reported to cause nephrotic syndrome with acute renal failure during the first months of continuous latent tuberculosis therapy 5.
- One study recommends close supervision by medical staff during all treatment duration, especially in case of renal or hepatic previous impairment 7.
- Another study reports a case of fatal poisoning with isoniazid and rifampicin, characterized by late presentation, lactic acidosis, and renal failure 6.
- There is no clear evidence to suggest that either Rifampicin or Isoniazid does not require dose adjustment in patients with impaired renal function.