The effects of a dopamine agonist (apomorphine) on experimental and spontaneous pain in patients with chronic radicular pain: A randomized, double-blind, placebo-controlled, cross-over study.

<h4>Background</h4>Although evidence suggests that dopaminergic systems are involved in pain processing, the effects of dopaminergic interventions on pain remains questionable. This randomized, double blinded, placebo-controlled, cross-over study was aimed at exploring the effect of the...

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Main Authors: May Haddad, Dorit Pud, Roi Treister, Erica Suzan, Elon Eisenberg
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2018-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0195287&type=printable
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author May Haddad
Dorit Pud
Roi Treister
Erica Suzan
Elon Eisenberg
author_facet May Haddad
Dorit Pud
Roi Treister
Erica Suzan
Elon Eisenberg
author_sort May Haddad
collection DOAJ
description <h4>Background</h4>Although evidence suggests that dopaminergic systems are involved in pain processing, the effects of dopaminergic interventions on pain remains questionable. This randomized, double blinded, placebo-controlled, cross-over study was aimed at exploring the effect of the dopamine agonist apomorphine on experimental pain evoked by cold stimulation and on spontaneous pain in patients with lumbar radicular (neuropathic) pain.<h4>Methods</h4>Data was collected from 35 patients with chronic lumbar radiculopathy (18 men, mean age 56.2±13 years). The following parameters were evaluated before (baseline) and 30, 75 and 120 minutes subsequent to a subcutaneous injection of 1.5 mg apomorphine or placebo: cold pain threshold and tolerance in the painful site (ice pack, affected leg) and in a remote non-painful site (12°C water bath, hand), and spontaneous (affected leg) pain intensity (NPS, 0-100).<h4>Results</h4>One-hundred and twenty minutes following apomorphine (but not placebo) injection, cold pain threshold and tolerance in the hand increased significantly compared to baseline (from a median of 8.0 seconds (IQR = 5.0) to 10 seconds (IQR = 9.0), p = 0.001 and from a median of 19.5 seconds (IQR = 30.2) to 27.0 seconds (IQR = 37.5), p<0.001, respectively). In addition, apomorphine prolonged cold pain tolerance but not threshold in the painful site (from a median of 43.0 seconds (IQR = 63.0) at baseline to 51.0 seconds (IQR = 78.0) at 120 min, p = 0.02). Apomorphine demonstrated no superiority over placebo in reducing spontaneous pain intensity.<h4>Conclusion</h4>These findings are in line with previous results in healthy subjects, showing that apomorphine increases the ability to tolerate cold pain and therefore suggesting that dopaminergic interventions can have potential clinical relevance.
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spelling doaj-art-e06b14c476574122abf73fd838f715b32025-08-20T02:28:58ZengPublic Library of Science (PLoS)PLoS ONE1932-62032018-01-01134e019528710.1371/journal.pone.0195287The effects of a dopamine agonist (apomorphine) on experimental and spontaneous pain in patients with chronic radicular pain: A randomized, double-blind, placebo-controlled, cross-over study.May HaddadDorit PudRoi TreisterErica SuzanElon Eisenberg<h4>Background</h4>Although evidence suggests that dopaminergic systems are involved in pain processing, the effects of dopaminergic interventions on pain remains questionable. This randomized, double blinded, placebo-controlled, cross-over study was aimed at exploring the effect of the dopamine agonist apomorphine on experimental pain evoked by cold stimulation and on spontaneous pain in patients with lumbar radicular (neuropathic) pain.<h4>Methods</h4>Data was collected from 35 patients with chronic lumbar radiculopathy (18 men, mean age 56.2±13 years). The following parameters were evaluated before (baseline) and 30, 75 and 120 minutes subsequent to a subcutaneous injection of 1.5 mg apomorphine or placebo: cold pain threshold and tolerance in the painful site (ice pack, affected leg) and in a remote non-painful site (12°C water bath, hand), and spontaneous (affected leg) pain intensity (NPS, 0-100).<h4>Results</h4>One-hundred and twenty minutes following apomorphine (but not placebo) injection, cold pain threshold and tolerance in the hand increased significantly compared to baseline (from a median of 8.0 seconds (IQR = 5.0) to 10 seconds (IQR = 9.0), p = 0.001 and from a median of 19.5 seconds (IQR = 30.2) to 27.0 seconds (IQR = 37.5), p<0.001, respectively). In addition, apomorphine prolonged cold pain tolerance but not threshold in the painful site (from a median of 43.0 seconds (IQR = 63.0) at baseline to 51.0 seconds (IQR = 78.0) at 120 min, p = 0.02). Apomorphine demonstrated no superiority over placebo in reducing spontaneous pain intensity.<h4>Conclusion</h4>These findings are in line with previous results in healthy subjects, showing that apomorphine increases the ability to tolerate cold pain and therefore suggesting that dopaminergic interventions can have potential clinical relevance.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0195287&type=printable
spellingShingle May Haddad
Dorit Pud
Roi Treister
Erica Suzan
Elon Eisenberg
The effects of a dopamine agonist (apomorphine) on experimental and spontaneous pain in patients with chronic radicular pain: A randomized, double-blind, placebo-controlled, cross-over study.
PLoS ONE
title The effects of a dopamine agonist (apomorphine) on experimental and spontaneous pain in patients with chronic radicular pain: A randomized, double-blind, placebo-controlled, cross-over study.
title_full The effects of a dopamine agonist (apomorphine) on experimental and spontaneous pain in patients with chronic radicular pain: A randomized, double-blind, placebo-controlled, cross-over study.
title_fullStr The effects of a dopamine agonist (apomorphine) on experimental and spontaneous pain in patients with chronic radicular pain: A randomized, double-blind, placebo-controlled, cross-over study.
title_full_unstemmed The effects of a dopamine agonist (apomorphine) on experimental and spontaneous pain in patients with chronic radicular pain: A randomized, double-blind, placebo-controlled, cross-over study.
title_short The effects of a dopamine agonist (apomorphine) on experimental and spontaneous pain in patients with chronic radicular pain: A randomized, double-blind, placebo-controlled, cross-over study.
title_sort effects of a dopamine agonist apomorphine on experimental and spontaneous pain in patients with chronic radicular pain a randomized double blind placebo controlled cross over study
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0195287&type=printable
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