Memantine for Post-Operative Pain Control

University of Washington

Status and phase: Unknown; Phase 4

Conditions: Pain, Post-operative

Treatments: Drug: Memantine; Drug: Placebo

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT01041313

NAM-MD-63

35063-A

Details and patient eligibility

About

Pain is a common element of surgery. Opiates (morphine, oxycodone, hydrocodone, methadone, fentanyl) are very helpful in decreasing pain after surgery. Unfortunately, with repeated use opiates lose their effectiveness, such that patients need to utilize more opiates to achieve adequate pain relief - a phenomenon called tolerance. Sometimes tolerance to a pain reliever's effects can develop in just a few hours. It is thought that activation of the N-methyl d-aspartate (NMDA) receptor, a "switch" found on the surface of nerves, is partially responsible for opiate tolerance. Memantine is a medication that limits the activity of NMDA receptors in the brain and spinal cord. It has been used for years to help patients with Alzheimer's Disease. In this study, we will study the effects of memantine when combined with opiate medications to see whether it can increase the effectiveness of opiates for pain after surgery and reduce the side effects caused by opiates (e.g., sedation, nausea, itching).

Enrollment: 120 estimated patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Surgery for total hip replacement, knee replacement OR lumbar spinal fusion
• Taking no opiate medication OR taking opiate medication for at least 6 weeks

Exclusion criteria

• History of alcohol or drug abuse
• Clinical diagnosis of Alzheimer's Disease
• Prior adverse reaction to memantine
• Severe renal impairment (creatinine clearance <30 ml/min)
• Inability to give informed consent

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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120 participants in 2 patient groups

Opiate Naive

Active Comparator group

Description:

Subjects who have not taken opiate medication in previous 6 weeks before surgery

Treatment:

Drug: Memantine

Drug: Placebo

Opiate tolerant

Active Comparator group

Description:

Subjects who have taken opiate medications for the 6 weeks before surgery

Treatment:

Drug: Memantine

Drug: Placebo