Pharmacokinetics of gabapentin in subjects with various degrees of renal function.

The pharmacokinetics of oral gabapentin (400 mg) was studied in normal subjects and in subjects with various degrees of renal function. Sixty subjects participated in this three-center study. None of the subjects were receiving hemodialysis. Plasma and urine samples were collected for up to 264 hours after dosing, and concentrations of gabapentin were determined by high performance liquid chromatography. Apparent oral plasma clearance (CL/F) and renal clearance (CLR) of gabapentin decreased and maximum plasma concentration, time to reach maximum concentration, and half-life values increased as renal function diminished. Gabapentin CL/F and CLR were linearly correlated with creatinine clearance. Total urinary recovery of unchanged drug was comparable in all subjects, indicating that the extent of drug absorption was unaffected by renal function. There was no evidence of gabapentin metabolism even in subjects with severe renal impairment. In summary, impaired renal function results in higher plasma gabapentin concentrations, longer elimination half-lives, and reduced CL/F and CLR values. Based on pharmacokinetic considerations, it appears that the dosing regimen of gabapentin in subjects with renal impairment may be adjusted on the basis of creatinine clearance.

Repeat admissions for perceived problem drinking. A social resources perspective.

Several propositions derived from a social resources perspective regarding differences in first and repeat admissions are examined using data taken from persons being treated for alcohol misuse and from persons not receiving treatment. Although objective behavior (drinking level) is very important as a predictor of first admissions, it is of less consequence in predicting repeat admissions. The data indicate a complex pattern of interaction effects among social resources and between them and drinking behavior in determining who comes to receive treatment and who is readmitted to treatment.