NCT02977208

Impact of Polymorphisms of OCT2 and OCTN1 on the Kinetic Disposition of Gabapentin in Patients Undergoing Chronic Use

Impact of Genetic Polymorphisms of OCT2 and OCTN1 on the Kinetic Disposition of Gabapentin in Patients Undergoing Chronic Use of the Drug

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 66 (actual)
• Sponsor: São Paulo State University · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This study aims to evaluate the influence of genetic polymorphisms of OCTN1 and OCT2 and other possible covariates on the kinetic disposition of GAB in patients undergoing GAB chronic treatment. Thus, patients treated with GAB, for at least one week, are being investigated.

Detailed description

Gabapentin (GAB), an anticonvulsant used for the treatment of epilepsy and chronic pain, has nonlinear kinetics, it is not metabolized and it is mainly eliminated by renal excretion. Studies suggest that the renal excretion of GAB is dependent on active secretion by organic cation transporter 2 (OCT2) and organic cation/ergothioneine transporter 1 (OCTN1). These transporters are expressed at the membrane of the renal proximal tubules and they are involved in the elimination of endogenous compounds and many drugs. The genetic polymorphism of drug transporters has been studied to explain the kinetic disposition variability of their substrates. The objective of this study is to investigate the influence of genetic polymorphisms of OCTN1 and OCT2 and other possible covariates (e.g., sex, age, creatinine clearance, body mass index) on the kinetic disposition of GAB in patients undergoing GAB chronic treatment. Patients treated with GAB, for at least one week, are being investigated. Blood and urine samples are being collected to GAB pharmacokinetic analysis, serum creatinine analysis and for genotyping. The plasma concentration of GAB will be assessed using liquid chromatography with UV detection (LC-UV).

Conditions

• Epilepsy
• Chronic Pain

Interventions

Type	Name	Description
PROCEDURE	Sparse blood sampling	Blood samples are being collected at times 0, 90 and 240 minutes after gabapentin administration.
PROCEDURE	Urine sampling	Urine samples are being collected during the dosing interval, only in patients hospitalized at Hospital Estadual de Américo Brasiliense (HEAB).
PROCEDURE	DNA extraction	Blood sample are being collected for DNA extraction. DNA are being extracted from the whole blood of all patients for genotyping of the SLC22A2 c.808G\>T and SLC22A4 c.1507C\>T polymorphisms
DRUG	Gabapentin	All patients undergoing chronic treatment with gabapentin are being recruited.

Timeline

• Start date: 2016-09-01
• Primary completion: 2018-02-01
• Completion: 2018-02-01
• First posted: 2016-11-30
• Last updated: 2018-04-18

Locations

1 site across 1 country: Brazil