MeDieViL
Bluelighter
- Joined
- Feb 11, 2007
- Messages
- 3,190
Lets see what research we got:
So looks like there are some indications it may help, but definatly not a miracle med.
The NMDA antagonist memantine attenuates the expression of opioid physical dependence in humans.
Bisaga A, Comer SD, Ward AS, Popik P, Kleber HD, Fischman MW.
Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, USA. [email protected]
Abstract
RATIONALE: Preclinical observations suggest that NMDA receptor-mediated glutamatergic neurotransmission is involved in the expression and maintenance of opioid dependence.
OBJECTIVE: The present study evaluated whether memantine, the clinically available non-competitive NMDA receptor antagonist, decreases naloxone-precipitated withdrawal in morphine-dependent humans.
METHODS: Eight heroin-dependent, non-treatment seeking, inpatient participants were stabilized on a fixed dose of morphine (30 mg PO qid). Subsequently, they received a series of challenges with naloxone (0.4 mg, IM) and the severity of opioid withdrawal was monitored. Either placebo or memantine (60 mg PO) was given 6 h before each naloxone challenge. A modified multiple baseline, across-participants design was used to evaluate the effects of memantine on the severity of naloxone-precipitated opioid withdrawal.
RESULTS: Naloxone increased ratings and produced physical changes consistent with opioid withdrawal. Memantine attenuated the severity of opioid withdrawal as assessed with the Clinical Institute for Narcotic Withdrawal Scale scale. Withdrawal was significantly reduced when naloxone was administered at 6 and 52 h after memantine, but not when administered 126 h (5 days) after memantine. Medication effects, assessed 5 h after memantine administration and before naloxone administration, included significant increases in ratings of "strong" and "good" drug effect, and "I feel sedated", "mellow", and "high".
CONCLUSIONS: Memantine attenuated the expression of opioid physical dependence in humans, indicating that glutamatergic neurotransmission at the NMDA receptor site contributes to the maintenance of opioid dependence. This finding suggests that memantine may be a useful adjunct in the treatment of opioid dependence.
Objectives: There is a growing body of evidence suggesting that N-methyl-D-aspartate (NMDA) receptor antagonists effectively counteract somatic and behavioral symptoms of the opioid withdrawal syndrome in humans and in laboratory animals. NMDA receptor blockade also reduces the development and expression of drug-conditioned behaviors. At present, there is only one NMDA receptor antagonist, memantine, registered for clinical use in Russia. Memantine is used in Europe for the treatment of Parkinson's disease and senile dementias. Most of heroin addicts soon after the termination of withdrawal syndrome are suffering from protracted withdrawal (syndrome of anhedonia [SA]), which includes affective disorders (depression and anxiety) and craving for heroin. SA is viewed as a major factor contributing to the relapse to heroin use.
The aim of this study was to evaluate efficacy of memantine in the treatment of protracted withdrawal (SA) in recently detoxified heroin addicts.
Methods: Following standard detoxification procedures (7-10 days), 67 heroin addicts were randomly assigned to 1 of 3 treatment groups: memantine (n = 21), amitriptyline (n = 24) or placebo (n = 22). While inpatients, subjects received one of the following medications: memantine (initial dose of 10 mg/day was gradually increased to the final dose of 30 mg/day over a period of 1 week), amitriptyline (75 mg/day), or placebo for a period of three weeks. Patients from all treatment groups received standard psychotherapy and counseling and were required to attain abstinence from heroin by providing a heroin-free urine toxicology screen prior to starting medications and at the end of each treatment week. The study design was single blind. Outcome measures included treatment retention, heroin craving (Visual Analog Scale), depression (Zung's scale), anxiety (Spielberger's scale) and anhedonia (Anhedonia syndrome scale) scores.
Results: Both memantine and amitriptyline significantly reduced heroin craving, depression, state and trait anxiety, and anhedonia scores at the end of the three-week treatment period; placebo did not have any significant effects. The dropout rate in the memantine group was significantly lower than that in either placebo or amitriptyline groups. The average number of side effects was higher in the amitriptyline group compared with other groups.
Conclusions: Memantine appears to be an effective and safe medication for protracted withdrawal (SA) and relapse prevention in recently detoxified heroin addicts. These data provide a rationale for further studies on the use of memantine in heroin dependence treatment.
Memantine produces modest reductions in heroin-induced subjective responses in human research volunteers
Rationale
Previous studies have demonstrated an interaction between opioids and noncompetitive antagonists at N-methyl-d-aspartate (NMDA) receptors, but few studies have examined the utility of these medications for treating opioid dependence.
Objective
In this 8-week inpatient study, participants were maintained on the low-affinity, noncompetitive NMDA receptor antagonist memantine (0, 30, and 60 mg per day, PO) and under each maintenance dose condition, the effects of intranasal heroin (0, 12.5, and 50 mg, IN) were examined.
Methods
During the first week after admission to the hospital, participants were detoxified from heroin. All of the volunteers received all of the memantine and heroin dose combinations. Participants (N = 8) first sampled a dose of heroin and $20. During a subsequent choice session, participants could self-administer heroin and/or money. Responses, which consisted of finger presses on a computer mouse, were made under a modified progressive ratio schedule (PR 50, 100, 200, 400, 800, 1,200, 1,600, 2,000, 2,400, and 2,800) during a ten-trial self-administration task. Subjective, performance, and physiological effects were measured repeatedly during laboratory sessions.
Results
Memantine produced modest reductions in subjective ratings of drug quality, liking, willingness to pay for the drug, and craving for heroin. However, memantine produced few changes in the reinforcing effects of heroin.
Conclusions
These data demonstrate that memantine was well tolerated and modestly effective in reducing the subjective but not the reinforcing effects of heroin. Although it is unlikely that memantine will be useful as a stand-alone maintenance medication for opioid dependence, it may have some utility as an adjunct treatment medication.
So looks like there are some indications it may help, but definatly not a miracle med.