Effects of N-Methyl-D-Aspartate (NMDA)-Receptor Antagonism on Hyperalgesia, Opioid Use, and Pain After Radical Prostatectomy

• Status: Unknown status
• Trial end date: 2006-12-01
• Target enrollment: 0
• Participant gender: Male

Summary

The primary aim is to determine whether perioperative NMDA-receptor antagonism has differential effects on postoperative pain, hyperalgesia and morbidity in younger and older patients. In order to achieve this aim, the researchers propose to conduct the first randomized, double-blind placebo-controlled study designed to investigate age differences in the effects of perioperative oral administration of an NMDA-receptor antagonist (amantadine) in men undergoing radical prostatectomy. In addition, age differences in psychosocial factors and the pharmacological properties of amantadine and morphine will be measured to control for, and clarify, their contribution to the differences found.

The specific objectives of the study are to:

1. investigate the effects of perioperative NMDA receptor blockade on postoperative hyperalgesia, pain and analgesic consumption in young and elderly men

2. assess age differences in the intensity and course of secondary hyperalgesia after surgery

• Phase: Phase 1/Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: University Health Network, Toronto
• Collaborator: Canadian Institutes of Health Research (CIHR)
• Treatments: Amantadine; Analgesics, Opioid

Criteria

Inclusion Criteria:

1. Able to read and write English;

2. Age 18-59 or >= 60 years;

3. American Society of Anesthesiologists Class 1 to 3;

4. Scheduled for elective radical prostatectomy;

5. Body weight between 50-110 kg, body mass index (BMI) <= 30.

Exclusion Criteria:

1. Significant central nervous system (CNS), respiratory, cardiac, hepatic, renal or endocrine dysfunction and/or any significant sequelae;

2. Contraindications, allergies to, and/or past adverse reactions to opioid analgesics, amantadine or nonsteroidal anti-inflammatory drugs (NSAIDS);

3. Current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM IV) Axis I disorder or cognitive dysfunction or history of this within the last year;

4. History of epilepsy or other seizures;

5. History of chronic pain of at least 6 months duration;

6. History of long term opioid use for chronic pain of at least 6 months duration;

7. History of long term use of amantadine or other antiparkinsonian drug;

8. Ingestion of antitussive medication (dextromethorphan) within the 48 hours before surgery;

9. History of alcohol or drug dependency/abuse of at least 6 months duration