Methadone and Ketamine for Neuropathic Pain Treatment

Management of Neuropathic Chronic Pain With Methadone Combined With Ketamine: Randomized, Double Blind, Active-controlled Clinical Trial

Status

Completed

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02233452

Enrollment

Registered

2014-09-08

Start date

2012-01-31

Completion date

2012-08-31

Last updated

2014-09-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Neuropathic Pain

Keywords

Neuropathic pain, Methadone, Ketamine, Multimodal analgesia

Brief summary

Methadone and ketamine are effective for neuropathic pain management. However, the benefits of the association of both drugs are uncertain. Here, the investigators conducted a randomized, double-blind, in parallel, active controlled clinical trial to test the hypothesis that methadone combined ketamine (methadone/ketamine) is more effective than methadone or ketamine alone in reducing neuropathic pain.

Detailed description

Either oral methadone or ketamine have been used in neuropathic pain management, however, the benefits of the association of both drugs are uncertain. Here, we conducted a randomized, double-blind, in parallel, active controlled clinical trial to test the hypothesis that methadone combined ketamine (methadone/ketamine) is more effective than methadone or ketamine alone in reducing neuropathic pain. Methods: Fourthly two patients with neuropathic pain refractory to conventional therapy were randomly assigned to receive during three months oral methadone (n= 13), ketamine (n=13) or methadone combined with ketamine (n=13). The primary outcome was pain score on visual analogical scale (VAS) assessed on baseline, 8, 15, 30, 60 and 90 days throughout the treatment, and the secondary outcomes were symptoms of neuropathic pain such as allodynia, burning or shooting pain as well the side effects.

Interventions

DRUGMethadone

The solution of methadone was prepared by mixing 10 ml of methadone (10 mg/ml) and 90 ml of saline 0.9% (Baxter, São Paulo, Brazil)

DRUGKetamine

The solution of ketamine was prepared by mixing 20 ml of S(+)-ketamine hydrochloride (50 mg/ml, Cristália®, São Paulo, Brazil) and 80 ml of saline 0.9% (Baxter, São Paulo, Brazil), obtaining a concentration of 10 mg/ml of ketamine.

DRUGMethadone plus Ketamine

the solution of methadone, ketamine was prepared by mixing 10 ml of methadone hydrochloride (10 mg/ml, Cristália®, São Paulo, Brazil), 20 ml of S(+)-ketamine hydrochloride (50 mg/ml, Cristália®, São Paulo, Brazil) and 70 ml of saline 0.9% (Baxter, São Paulo, Brazil), obtaining a concentration of 1 mg/ml of methadone and 10 mg/ml of ketamine.

Study design

Allocation

RANDOMIZED

Intervention model

FACTORIAL

Primary purpose

TREATMENT

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

22 Years to 77 Years

Healthy volunteers

Inclusion criteria

* patients complaining of pain for more than 6 months with neuropathic pain poorly responsive to drugs used to treat neuropathic pain (i.e. opioid, non-opioid, anticonvulsants, antidepressants), who were 22 to 77 years old

Exclusion criteria

* patients with a history of severe psychiatric disorder, * misuse of illegal drugs or * hepatic disease

Design outcomes

Primary

Measure	Time frame
The primary outcome was pain intensity as assessed by visual analogical scale (VAS) scores	90 days

Secondary

Measure	Time frame
The secondary outcomes were the presence of burning and/or shooting pain, allodynia and side effects.	90 days

Countries

Brazil

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026