Ceftriaxone Dosing in Renal Impairment (GFR 35)
Yes, you can safely administer 1 gram of ceftriaxone to a patient with a GFR of 35 mL/min without dose adjustment. 1
No Dose Adjustment Required
Ceftriaxone does not require dose reduction in renal impairment because it has dual excretion pathways (both biliary and renal). 2, 1
The FDA label explicitly states: "patients with renal failure normally require no adjustment in dosage when usual doses of ceftriaxone are administered." 1
Dosage adjustments are only necessary when BOTH severe hepatic dysfunction AND significant renal disease are present together, and even then, the maximum daily dose is 2 grams. 1
For isolated renal impairment (even in functionally anephric patients), the half-life increases only modestly from 8 hours to approximately 12 hours, which does not necessitate dose adjustment. 3
Pharmacokinetic Rationale
Between 30-60% of ceftriaxone is eliminated through non-renal (biliary) mechanisms, which substantially reduces the need for dose adjustments in mild to moderate renal impairment. 3
In patients with various degrees of renal impairment (including those on dialysis), the elimination half-life is prolonged twofold and plasma clearance is lowered less than 50%, but these changes are moderate enough that no adjustment is needed for doses ≤2 grams per day. 4
Ceftriaxone is not removed by hemodialysis or peritoneal dialysis, so no supplementary dosing is required following dialysis. 1
Important Safety Considerations
Monitor for neurotoxicity, particularly if using high doses or prolonged therapy. While ceftriaxone is considered safe in renal insufficiency, case reports document ceftriaxone-induced encephalopathy in patients with renal dysfunction, especially with high-dose therapy. 5
Ensure adequate hydration to prevent ceftriaxone-calcium precipitates in the urinary tract, which can cause urolithiasis and post-renal acute renal failure. 1
Monitor for gallbladder pseudolithiasis, as ceftriaxone-calcium precipitates can form in the gallbladder, though this condition is reversible upon discontinuation. 1
Advantages Over Nephrotoxic Alternatives
Ceftriaxone is specifically preferred over aminoglycoside-containing regimens in patients with renal impairment to avoid exacerbating kidney damage. 2
Unlike vancomycin (which requires significant dose reduction to 310 mg/24h at CrCl 20 mL/min), ceftriaxone maintains standard dosing in renal impairment. 2