NCT05235191

Effectiveness and Safety of Methadone Versus Placebo for the Control of Neuropathic Pain in Different Etiologies

A Randomized Controlled Trial Study to Assess the Effectiveness and Safety of Methadone Versus Placebo for the Control of Neuropathic Pain in Different Etiologies

• Status: Completed
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 80 (actual)
• Sponsor: University of Sao Paulo · Academic / Other
• Sex: All
• Age: 18 Years – 85 Years
• Healthy volunteers: Not accepted

Summary

Opioids are currently ranked as third-line agents for neuropathic pain (NP) treatment. The opioids more frequently tested for NP were tramadol, oxycodone and morphine. In the present study test the safety and effectiveness of methadone in patients with NP who remain symptomatic despite the use of first and second line drugs in a placebo-controlled randomized approach.

Detailed description

Background: neuropathic pain (NP) is highly refractory and it is estimated that about 40% of patients remain symptomatic despite the use of first and second line drugs. Opioids are currently ranked as third-line agents for NP treatment. The opioids more frequently tested for NP were tramadol, oxycodone and morphine. In the present study test the effectiveness and safety of methadone, an opioid agonist and glutamate n-methyl-d-aspartate (NMDA) receptor antagonist in patients with NP who remain symptomatic despite the use of first and second line drugs in a placebo-controlled randomized approach. Patients and Methods: this is a randomized, placebo controlled superiority trial including 80 subjects, aged between 18 and 85 years, with NP, that will be randomized to receive methadone or placebo in a 1:1 ratio. Enrollment will take place at the Pain Center of the University of São Paulo and it will include patients from primary care clinics from an area of 2 million people addressed to specialized care at a referral center. Expected results: the study hypothesis is that methadone is superior to placebo and it is safe to use that medication in patients with neuropathic pain. Recruitment time will be extended by 12 months due to dropouts related to the Covid pandemic. We have had dropouts due to a few patients developing covid and also due to patients having fear to become infected while attending hospital visits

Conditions

• Neuropathic Pain

Interventions

Type	Name	Description
DRUG	methadone tablets	The intervention with the active drug (methadone) will start with the dose of 1 tablet (5 mg) twice a day (every 12 hours) and titrated on subsequent visits up to the maximum dose of 6 tablets a day (totaling 30 mg divided into 2 daily doses to facilitate therapeutic adherence).
DRUG	Placebo	In this arm patients will take placebo tablets (the same number, color and physical aspects as the methadone tablets).

Timeline

• Start date: 2019-09-06
• Primary completion: 2023-01-20
• Completion: 2023-01-20
• First posted: 2022-02-11
• Last updated: 2023-02-08

Locations

1 site across 1 country: Brazil