Hyperalgesia in Methadone Patients: Can it be Treated?

• Status: Unknown status
• Trial end date: 1969-12-31
• Target enrollment: 0
• Participant gender: All

Summary

In the proposed study, we will build upon our previous studies validating and characterizing hyperalgesia in MM samples to explore it's underlying mechanism from a pharmacological perspective. Utilizing a double-blind, placebo-controlled designs, the proposed work will evaluate the ability of dextromethorphan , an N-methyl-D-aspartate (NMDA)-antagonists to diminish or reverse the opioid-induced hyperalgesia complicating the pain states suffered by MM patients. Specifically, in a sample of MM patients, dextromethorphan, theorized to interfere with the development of opioid-induced hyperalgesia will be evaluated for its ability to ameliorate or diminish the opioid-induced hyperalgesia in these patients as reflected by changes on pain threshold and tolerance to both cold-pressor and electrical pain, at peak and trough methadone blood levels. The results of this work will not only provide pharmacologic insight into the mechanisms underlying poor pain tolerance in this at-risk population, but also direction for the medical management of pain complicated by opioid-induced hyperalgesia.

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

Details

• Lead Sponsor: National Institute on Drug Abuse (NIDA)
• Treatments: Dextromethorphan; Methadone

Criteria

Inclusion Criteria:

• Inclusion criteria: Potential participants must:

1. Be between the ages of 18 and 55 years of age.

2. Fulfill DSM-IV criteria for opiate dependence.

3. Be compliant in MM treatment and on a stable dose of methadone x 6 weeks.

4. Be in good physical health or in the case of a medical condition needing ongoing treatment, be in the care of a physician who is willing to take responsibility for such treatment. The same conditions apply in cases of patients with a psychiatric disorder needing ongoing treatment.

5. Be agreeable to and capable of signing an informed consent.

Exclusion Criteria:

• Exclusion Criteria: Potential participants must not:

1. Have known sensitivity to dextromethorphan, gabapentin or oxycodone.

2. Be dependent on alcohol, benzodiazepine or other drugs of abuse (except nicotine).

3. Have any acute medical condition that would make participation medically hazardous, (e.g., acute hepatitis, unstable cardiovascular disease, liver or renal disease) or have liver enzyme values (AST or ALT) greater than 5 times normal range.

4. Be acutely psychotic, severely depressed and in need of inpatient treatment, or an immediate suicide risk.

5. Have a neurological or psychiatric illness (i.e., peripheral neuropathy, schizophrenia, neuropathic pain, Raynaud's disease, urticaria,) that would affect pain responses.

6. Be currently taking analgesic medication (opioid or otherwise) for a painful condition on a regular basis.

7. Be a nursing or pregnant female. Female of childbearing potential must agree to use a medically acceptable method of birth control, (e.g. oral contraceptives, barrier (diaphragm or condom) with or without spermicide, levonorgestrel implant, intra-uterine progesterone contraceptives system, medroxyprogesterone acetate contraceptive injection) or to complete abstinence. Females who become pregnant during the course of the study will be dropped from the study.

8. Have a current or past history of high blood pressure, heart disease, stroke or currently have a pacemaker.