From the FDA Drug Label
Use in Patients with Impaired Hepatic or Renal Function Buspirone is metabolized by the liver and excreted by the kidneys. A pharmacokinetic study in patients with impaired hepatic or renal function demonstrated increased plasma levels and a lengthened half-life of buspirone Therefore, the administration of buspirone hydrochloride tablets to patients with severe hepatic or renal impairment cannot be recommended
Buspar Safety for Kidneys:
- The administration of buspirone to patients with severe renal impairment cannot be recommended due to increased plasma levels and a lengthened half-life of buspirone.
- In patients with renal impairment (Clcr = 10 to 70 mL/min/1.73 m2), the steady-state AUC of buspirone increased 4-fold compared to healthy subjects 1, 1.
- Caution is advised when using buspirone in patients with impaired renal function.
From the Research
Buspirone (Buspar) can be used with caution in patients with impaired renal function, but dose adjustments may be necessary, as evidenced by a study from 1994 2 that showed higher plasma concentrations of buspirone and its metabolite 1-PP in patients with renal impairment. When considering the use of buspirone in patients with impaired renal function, it's essential to weigh the potential benefits against the risks. The primary concern is the accumulation of buspirone's metabolites, which could lead to increased side effects such as dizziness, headache, nervousness, and nausea.
- For patients with mild to moderate renal impairment, standard dosing can often be maintained with careful monitoring, as the pharmacokinetics of buspirone are similar to those in individuals with normal renal function, according to a study from 1988 3.
- However, in severe renal impairment (creatinine clearance <30 mL/min), the initial dose should be reduced to 2.5 mg twice daily and titrated slowly, with a maximum recommended dose of 60 mg daily, to minimize the risk of adverse effects.
- Close monitoring for side effects is crucial, as the drug's metabolites may accumulate in these patients, and buspirone is primarily metabolized by the liver through the CYP3A4 enzyme system, but approximately 30-63% of a dose is excreted through the kidneys as metabolites, which explains why renal function affects its clearance, as noted in a study from 1999 4.
- Unlike benzodiazepines, buspirone doesn't cause significant respiratory depression or physical dependence, making it a potentially safer anxiolytic option for patients with kidney disease who need treatment for anxiety disorders, as highlighted in a study from 1987 5.