NCT02246712

Influence of Diabetes on Tramadol Pharmacokinetics

Influence of Uncontrolled Diabetes on the Kinetic Disposition, Metabolism and Pharmacokinetics-pharmacodynamics of Tramadol Enantiomers in Patients With Neuropathic Pain

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 30 (actual)
• Sponsor: Universidade Estadual Paulista Júlio de Mesquita Filho · Academic / Other
• Sex: All
• Age: 18 Years – 59 Years
• Healthy volunteers: Not accepted

Summary

This study aimed to investigate the influence of uncontrolled type 1 and type 2 diabetes mellitus (DM) on the kinetic disposition, metabolism and pharmacokinetics-pharmacodynamics of tramadol enantiomers in patients with neuropathic pain. Thus, nondiabetic patients (control group, n = 12), patients with type 1 DM (n = 9), and patients with type 2 DM (n = 9), all with neuropathic pain and phenotyped as extensive metabolizers of cytochrome P450 2D6 (CYP2D6) who were treated with a single oral dose of 100 mg racemic tramadol were investigated.

Detailed description

Tramadol is a centrally acting analgesic that effectively relieves acute and chronic pain, including neuropathic pain in diabetic patients. The drug is available in clinical practice as a mixture of the (+)-tramadol and (-)-tramadol enantiomers. Tramadol is metabolized by CYP2D6 to O-desmethyltramadol (M1) and by cytochrome P450 3A (CYP3A4) and cytochrome P450 2B6 (CYP2B6) to N-desmethyltramadol (M2). Both tramadol enantiomers and (+)-M1 contribute to the analgesic activity of the drug: (+)-tramadol and the (+)-M1 metabolite act as -opioid receptor agonists; (+)-tramadol inhibits serotonin reuptake; and (-)-tramadol inhibits the reuptake of norepinephrine. This study investigated the influence of uncontrolled type 1 and type 2 diabetes mellitus (DM) on the kinetic disposition, metabolism and pharmacokinetics-pharmacodynamics of tramadol enantiomers in patients with neuropathic pain. Nondiabetic patients (control group, n = 12), patients with type 1 DM (n = 9), and patients with type 2 DM (n = 9), all with neuropathic pain and phenotyped as extensive metabolizers of CYP2D6, received a single oral dose of 100 mg racemic tramadol. Serial blood samples were collected up to 24 h after administration of the drug for pharmacokinetic study and for the analysis of noradrenaline in plasma. Pain was rated on a visual analog pain scale at the same time as blood sampling. The patients were evaluated for in vivo CYP3A activity using midazolam as a probe drug and genotyped for CYP2B6. Total and unbound plasma concentrations of the tramadol, M1 and M2 enantiomers were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS).

Conditions

• Neuropathic Pain
• Type 1 Diabetes Mellitus
• Type 2 Diabetes Mellitus

Interventions

Type	Name	Description
DRUG	Single oral dose of 100 mg racemic tramadol	Serial blood samples were collected up to 24 h after drug administration; Pain was evaluated at the same time of blood sampling using visual analog scale
OTHER	CYP2D6 phenotype	Patients were phenotyped using metoprolol (100 mg, single oral dose). Urine was collected up to 8 hours after metoprolol administration. Urinary concentrations of metoprolol and alfa-hydroxymetoprolol were determined by high performance liquid chromatography (HPLC), using fluorescence detector. CYP2D6 phenotyped was determined by alfa-hydroxymetoprolol/metoprolol urinary rato
OTHER	CYP3A phenotype	A single oral dose of midazolam (15 mg) was administered to all patients. Serial blood samples were collected up to 6 hours after the administration of midazolam. The concentration of midazolam was determined in plasma in order to calculate midazolam clearance. The in vivo activity of CYP3A was evaluated by midazolam oral clearance.
GENETIC	CYP2B6 genotype	The single nucleotide polymorphism 516G\>T in CYP2B6 gene was evaluated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Timeline

• Start date: 2008-06-01
• Primary completion: 2010-05-01
• Completion: 2011-12-01
• First posted: 2014-09-23
• Last updated: 2014-09-23

Locations

1 site across 1 country: Brazil