Clinical Trial: Ibudilast in the Treatment of Medication Overuse Headache

Study Status: Completed
Recruit Status: Unknown status
Study Type: Interventional

Official Title: Ibudilast in the Treatment of Medication Overuse Headache: A Double-blind, Randomised, Placebo-controlled Pilot Study

Brief Summary: The purpose of this study is to determine if ibudilast is effective in reverting patients with medication overuse headache suffering chronic daily headache back to their original episodic headache pattern.

Detailed Summary:

It has been established that excessive intake of medications used to treat primary headaches, particularly those containing opioids, can induce a form of secondary headache, known as medication overuse headache (MOH). Despite the significant clinical impact of this condition the mechanisms behind MOH remain poorly understood, guidelines for treatment are lacking, and relapse is common.

Recently, it has been recognised that repeated opioid exposure can facilitate pain by activating glia, the immunocompetent cells of the central nervous system, resulting in opioid-induced hyperalgesia (OIH).

The investigators hypothesise that MOH represents a form of OIH in this susceptible patient group - repeated activation of nociceptive pathways by frequent headaches interacts with the opioid induced pro-inflammatory actions of activated glia to produce chronic daily headache (CDH).

This double-blind, randomised, placebo controlled pilot study will investigate the use of ibudilast, a know attenuator of glial activation, in the treatment of medication overuse headache.


Sponsor: University of Adelaide

Current Primary Outcome: Headache Index [ Time Frame: 2, 4, 8, 24 weeks ]

Headache Index as calculated by the summation of headache duration (hours) X headache intensity (11-point numerical rating scale), over the final two weeks of treatment.


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Medication frequency [ Time Frame: 2, 4, 8, 24 weeks ]
    Defined as number of days acute headache medication taken over the previous month.
  • Headache frequency [ Time Frame: 2, 4, 8, 24 weeks ]
    Defined as number of days with headache over the previous month
  • Duration of headache [ Time Frame: 2, 4, 8, 24 weeks ]
    Average duration of headache in hours over previous 2 weeks
  • Intensity of headache [ Time Frame: 2, 4, 8, 24 weeks ]
    Average intensity of headache assessed by numerical rating scale over previous 2 weeks
  • Frequency of probable migraine attacks [ Time Frame: 2, 4, 8, 24 weeks ]
    Defined as number of probable migraine attacks (using International Classification of Headache Disorders, second edition, criteria for diagnosis of migraine/migraine with aura) over previous month
  • Headache related impact on quality of life [ Time Frame: 2, 4, 8, 24 weeks ]
    As assessed via the six-item the Headache Impact Test
  • Allodynia symptom checklist score [ Time Frame: 2, 4, 8, 24 weeks ]
    Assesses presence of cutaneous allodynia during activities of daily living
  • Von Frey filament test [ Time Frame: 2, 4, 8, 24 weeks ]
    To assess sensitivity to static mechanical cutaneous allodynia
  • Brush allodynia test [ Time Frame: 2, 4, 8, 24 weeks ]
    To assess sensitivity to dynamic mechanical cutaneous allodynia
  • Response rate [ Time Frame: 2, 4, 8, 24 weeks ]
    Response defined as ≥ 30% reduction in headache days/month or headache index from baseline. Expressed as percentage of patients who saw a ≥ 30% reduction in headache index after ibudilast treatment (at week 8) and NNT, number of patients treated to see 1 patient "respond".
  • Relapse rate [ Time Frame: 2, 4, 8, 24 weeks ]
    Expressed as the percentage of patients who were initially classed as responders (at weeks 8) who no longer meet the criteria for responders at 6 months


Original Secondary Outcome: Same as current

Information By: University of Adelaide

Dates:
Date Received: March 17, 2011
Date Started: April 2011
Date Completion: August 2013
Last Updated: February 4, 2013
Last Verified: February 2013