Memantine for Post-Operative Pain Control

Phase 4

• Conditions: Pain, Post-operative
• Interventions: Drug: Memantine; Drug: Placebo

• Registration Number: NCT01041313
• Lead Sponsor: University of Washington

Brief Summary

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).

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2009-12-29
• Study First Submitted QC: 2009-12-30
• Study First Posted: 2009-12-31
• Study Start: 2010-01
• Status Verified: 2010-06
• Last Update Submitted: 2010-06-25
• Last Update Posted: 2010-06-29
• Primary Completion: 2011-06
• Study Completion: 2011-09

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 120

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Opiate Naive	Placebo	Subjects who have not taken opiate medication in previous 6 weeks before surgery
Opiate tolerant	Placebo	Subjects who have taken opiate medications for the 6 weeks before surgery
Opiate Naive	Memantine	Subjects who have not taken opiate medication in previous 6 weeks before surgery
Opiate tolerant	Memantine	Subjects who have taken opiate medications for the 6 weeks before surgery

Primary Outcome Measures

Name	Time	Method
Change in numerical ratings on pain diaries as outpatients (pre and post surgery)	For 1 week pre-surgery, through 2 weeks post-surgery
Daily pain numerical ratings at rest and with movement as inpatients.	Immediately post-surgery until discharge (2-3 days)
Total opiate dose via patient controlled IV hydromorphone	Post-surgery day 1
Oxycodone dose taken prn	Post-surgery day 2 through 3 months.

Secondary Outcome Measures

Name	Time	Method
Treatment group differences in side effects (nausea, itching, sedation, urinary retention following foley catheter discontinuation)	One week pre-surgery through 3 months post-surgery
Changes in cognitive function, assessed with Digit-Symbol Substitution Test and Trail Making Test B	One week pre-surgery, immediately pre-surgery, and post-surgery days 1, 2, 3
Changes in pain and quality of life questionnaire responses (SF-McGill-2, Brief Pain Questionnaire, SF-36 v2)	One week pre-surgery through 3 months post-surgery, particularly as outpatient

Trial Locations

Locations (1)

University of Washington Medical Center; 🇺🇸 Seattle, Washington, United States