Clinical trial NCT01560442: Pupillometry and Pain Thresholds Patients Substituted by Methadone and Buprenorphine
Official title: Pupillometry and Pain Thresholds Patients Substituted by Methadone and Buprenorphine.
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Opiate Dependent
Previous Illicit Drug Use
Keywords: Analgesics, opioids
Opiate substitution treatment
Methadone
Buprenorphine
Hyperalgesia
Pupil
Pain
Psychophysics
previous illicit drug intake, under a substitution program
Lead sponsor: University Hospital, Clermont-Ferrand
Sponsor class: OTHER
Collaborators: name: CSAPA ANPAA 63
First posted: 2012-03-22
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Opiate dependent patients

Brief summary: The purpose is to study the relation between pupillary diameter measured under scotopic conditions, and the pain thresholds measured at the time of peak and residual effect of methadone/buprenorphine in opiate-dependent patients following a substitution program.

Detailed description: Patients substituted since at least 3 months shall be included during a regular control visit.

Each session shall consist in

* check for toxics in urine sample;
* measurement of pupil diameter;
* measurement of mechanical punctuate pain threshold;
* measurement of mechanical bone pain threshold.

A first session shall be done at time of residual effect of the opiate. A second session shall be done at time of peak effect of the opiate.

Eligibility criteria: Inclusion Criteria:

* substitution treatment stable since at least 3 months
* capacity to understand the protocol
* likely to come to visits
* covered by French welfare

Exclusion Criteria:

* chronic pain
* concomitant acute pain
* pregnancy or breast feeding
* relevant mental disease
* peripheral neuropathy
* diabetes
* regular intake of ketamine
* neuroleptic concomitant treatment

Primary outcomes:
measure: Measurement of the pupil diameter
timeFrame: 24 hours after the last dose of treatment
Secondary outcomes:
measure: - The mechanical punctuate pain threshold as measured by Electronical Von Frey
timeFrame: 24 hours after the last dose of treatment, 3 hours after the last dose of methadone and 1 hour ½ after the last dose of buprenorphine
measure: - The mechanical pressure pain threshold measured by Algometer on the tibial bone
timeFrame: 24 hours after the last dose of treatment, 3 hours after the last dose of methadone and 1 hour ½ after the last dose of buprenorphine
measure: - The pupil diameter measured in scotopic .conditions (via infrared camera) at the hypothetical peak effect of either methadone or buprenorphine.
timeFrame: 24 hours after the last dose of treatment, 3 hours after the last dose of methadone and 1 hour ½ after the last dose of buprenorphine
measure: - The pupil diameter measured in photopic conditions (via infrared camera) at the hypothetical residual effect of either methadone or buprenorphine
timeFrame: 24 hours after the last dose of treatment, 3 hours after the last dose of methadone and 1 hour ½ after the last dose of buprenorphine
Other outcomes:
Locations:
city: Clermont-Ferrand
country: France
facility: CHU Clermont-Ferrand
Study officials:
affiliation: University Hospital, Clermont-Ferrand
name: Nicolas AUTHIER
role: PRINCIPAL_INVESTIGATOR
References: