Effects of Pentazocine on Manic Symptoms

Condition(s) targeted: Bipolar Disorder

Intervention: Talwin Nx (Drug)

Phase: Phase 2

Status: Active, not recruiting

Sponsored by: Mclean Hospital

Official(s) and/or principal investigator(s):
Beth L Murphy, MD, PhD, Principal Investigator, Affiliation: Mclean Hospital

The opiate neurotransmitter system is thought to be involved in many abnormal mood states. Some researchers have suggested that changes in this system may trigger the switch to/from manic and depressive states in bipolar disorder. One problem with most of the currently available opiate medications is that they can produce addiction/dependence. A particular kind of opiate medication known as kappa-opiates may be able to produce changes in this system with much less risk of addiction. This study looks at Talwin (a combination of pentazocine and naloxone), a medication which affects the kappa and mu opiate systems. The study will examine whether two doses of Talwin affect manic symptoms in people who have been admitted to the hospital. This study will give more information about the involvement of the opiate system in bipolar disorder, and give important information for use in developing new treatments.

Official title: Inpatient Clinical Trial Examining the Effects of Pentazocine on Manic Symptoms

Study design: Treatment, Non-Randomized, Open Label, Uncontrolled, Single Group Assignment, Efficacy Study

Primary outcome: mania rating scale

Secondary outcome:

hours of sleep

use of adjunctive 'as needed' medications

mania symptoms self-report

Detailed description: Opiates have a long history of treating mood disorders. Some researchers have suggested that changes in this system may trigger the switch to/from manic and depressive states in bipolar disorder. The clinical use of opiate medications has been limited by their abuse/dependence potential. Studies of opiate receptor subtypes have raised the possibility that medications targeting the kappa/dynorphin system could be used to target mood symptoms with reduced/limited addiction potential. Rodent studies at Mclean indicate that kappa-agonists have pro-depressant effects and kappa-antagonists have anti-depressant effects. In addition, antimanic/antipsychotic medications regulate the activity of dynorphin cells. This study is a pilot open-label investigation using Talwin, a combination of pentazocine and naloxone. Pentazocine is a kappa agonist and mixed mu agonist. Two doses of Talwin will be given to acutely manic inpatients in a cumulative-dosing strategy. Measurements of manic symptoms will be conducted before, during, and after administration. This study will determine whether pentazocine has an immediate or sustained impact on acute mania symptoms.

Minimum age: 18 Years. Maximum age: 60 Years. Gender(s): Both.

Criteria:

Inclusion Criteria:

- Young Mania Rating Scale (YMRS) greater than 14

- Inpatient

Exclusion Criteria:

- History of opiate abuse/dependence

- Recent history of substance abuse

- Pregnancy

- Unstable medical issues

- Use of opiate medications for pain management

McLean Hospital, Belmont, Massachusetts 02478, United States

McLean hospital website, with links to research.

Related publications:

Ma J, Ye N, Lange N, Cohen BM. Dynorphinergic GABA neurons are a target of both typical and atypical antipsychotic drugs in the nucleus accumbens shell, central amygdaloid nucleus and thalamic central medial nucleus. Neuroscience. 2003;121(4):991-8.

Carlezon WA Jr, Beguin C, DiNieri JA, Baumann MH, Richards MR, Todtenkopf MS, Rothman RB, Ma Z, Lee DY, Cohen BM. Depressive-like effects of the kappa-opioid receptor agonist salvinorin A on behavior and neurochemistry in rats. J Pharmacol Exp Ther. 2006 Jan;316(1):440-7. Epub 2005 Oct 13.

Mague SD, Pliakas AM, Todtenkopf MS, Tomasiewicz HC, Zhang Y, Stevens WC Jr, Jones RM, Portoghese PS, Carlezon WA Jr. Antidepressant-like effects of kappa-opioid receptor antagonists in the forced swim test in rats. J Pharmacol Exp Ther. 2003 Apr;305(1):323-30.

Todtenkopf MS, Marcus JF, Portoghese PS, Carlezon WA Jr. Effects of kappa-opioid receptor ligands on intracranial self-stimulation in rats. Psychopharmacology (Berl). 2004 Apr;172(4):463-70. Epub 2004 Jan 16.

Starting date: September 2005
Ending date: December 2008
Last updated: January 17, 2008