Efficacy, Safety, Tolerability and Pharmacokinetics of Concomitant Administration of Tramadol With Duloxetine or Pregabalin

Sponsor

Turku University Hospital (Other)

Overall Status

Withdrawn

CT.gov ID

NCT01116531

Collaborator

University of Helsinki (Other)

Enrollment

Location

Arms

Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Tramadol is an opioid analgesic, which is widely used in the treatment of acute and neuropathic pain. Treatment of neuropathic pain often requires a combination of pain medications due to the complex nature of neuropathic pain and frequent inadequate response to drug treatment. Common drugs used concomitantly with tramadol are SNRI antidepressant duloxetine and anticonvulsants such as pregabalin. Both tramadol and duloxetine have serotonergic effects and duloxetine has also a potential to inhibit metabolism of tramadol. The objective of the study is to investigate the pharmacokinetics and pharmacodynamic interaction of oral tramadol with duloxetine and pregabalin in patients with chronic neuropathic pain due to postherpetic neuralgia or diabetic polyneuropathy. All subjects will receive tramadol and duloxetine or tramadol and pregabalin in a randomized double-blind order. Primary end point is O-desmethyltramadol concentration.

Condition or Disease	Intervention/Treatment	Phase
Diabetic Polyneuropathy Postherpetic Neuralgia	Drug: Tramadol Drug: Duloxetine Drug: Pregabalin	Phase 4

Study Design

Study Type:

Interventional

Actual Enrollment :

0 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Triple (Participant, Care Provider, Investigator)

Primary Purpose:

Treatment

Official Title:

Efficacy, Safety, Tolerability and Pharmacokinetics of Concomitant Administration of Tramadol With Duloxetine or Pregabalin: a Randomized Controlled Flexible-dose Study in Patients With Neuropathic Pain

Study Start Date :

Apr 1, 2010

Actual Primary Completion Date :

Dec 1, 2012

Anticipated Study Completion Date :

Dec 1, 2012

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: Duloxetine and tramadol To ascertain the double-blinding of subjects and investigators, duloxetine and pregabalin will be administered as 2 similar capsules twice a day. Each of these capsules will contain either 30mg of duloxetine, 75 mg of pregabalin or placebo. Capsules will be prepared at the hospital pharmacy.	Drug: Tramadol Initial dose of oral tramadol (depottabl Tramal retard, Orionpharma, Finland) will be 100mg once daily. If the subject is currently on opioid treatment with codeine, tramadol or buprenorphine, the opioid treatment will be stopped, and an equal dose of tramadol will be used as the initial dose. The dose will be titrated on visits V2 and V3 based on the adequacy of pain relief and tolerability. If pain intensity ≥ 4 on a numeric rating scale of 0-10 during V2 and V3 and tramadol is well tolerated, the daily dose will be increased by 100mg. The maximum daily dose of 400 mg tramadol will not be exceeded. If the subject does not tolerate the initial dose of tramadol, he/she will be dropped out of the study and replaced by another patient. Drug: Duloxetine The initial dose of duloxetine (Cymbalta, Eli Lilly, USA) will be 30mg once daily. The dose will be titrated on V2 based on the adequacy of pain relief and tolerability. If pain intensity during V2 is < 4 on a scale of 0-10, the dose of duloxetine dose will be 30mg daily throughout the study. If pain intensity is ≥ 4 on a numeric rating scale of 0-10 and duloxetine is well tolerated, the daily dose will be increased to 60mg once daily. If the subject does not tolerate the initial dose of duloxetine, he/she will be dropped out of the study and replaced by another patient.
Active Comparator: Pregabalin and tramadol To ascertain the double-blinding of subjects and investigators, duloxetine and pregabalin will be administered as 2 similar capsules twice a day. Each of these capsules will contain either 30mg of duloxetine, 75 mg of pregabalin or placebo. Capsules will be prepared at the hospital pharmacy.	Drug: Tramadol Initial dose of oral tramadol (depottabl Tramal retard, Orionpharma, Finland) will be 100mg once daily. If the subject is currently on opioid treatment with codeine, tramadol or buprenorphine, the opioid treatment will be stopped, and an equal dose of tramadol will be used as the initial dose. The dose will be titrated on visits V2 and V3 based on the adequacy of pain relief and tolerability. If pain intensity ≥ 4 on a numeric rating scale of 0-10 during V2 and V3 and tramadol is well tolerated, the daily dose will be increased by 100mg. The maximum daily dose of 400 mg tramadol will not be exceeded. If the subject does not tolerate the initial dose of tramadol, he/she will be dropped out of the study and replaced by another patient. Drug: Pregabalin The initial dose of pregabalin (Lyrica, Pfizer, USA) will be 75mg twice a day. The dose will be titrated on V2 based on the adequacy of pain relief and tolerability. If pain intensity during V2 is < 4 on a scale of 0-10, the initial dose of pregabalin dose will be continued. If pain intensity is ≥ 4 on a numeric rating scale of 0-10 and pregabalin is well tolerated, the daily dose will be increased to 150mg twice a day. If the subject does not tolerate the initial dose of pregabalin, he/she will be dropped out of the study and replaced by another patient.

Arm

Intervention/Treatment

Active Comparator: Duloxetine and tramadol

To ascertain the double-blinding of subjects and investigators, duloxetine and pregabalin will be administered as 2 similar capsules twice a day. Each of these capsules will contain either 30mg of duloxetine, 75 mg of pregabalin or placebo. Capsules will be prepared at the hospital pharmacy.

Drug: Tramadol

Initial dose of oral tramadol (depottabl Tramal retard, Orionpharma, Finland) will be 100mg once daily. If the subject is currently on opioid treatment with codeine, tramadol or buprenorphine, the opioid treatment will be stopped, and an equal dose of tramadol will be used as the initial dose. The dose will be titrated on visits V2 and V3 based on the adequacy of pain relief and tolerability. If pain intensity ≥ 4 on a numeric rating scale of 0-10 during V2 and V3 and tramadol is well tolerated, the daily dose will be increased by 100mg. The maximum daily dose of 400 mg tramadol will not be exceeded. If the subject does not tolerate the initial dose of tramadol, he/she will be dropped out of the study and replaced by another patient.

Drug: Duloxetine

The initial dose of duloxetine (Cymbalta, Eli Lilly, USA) will be 30mg once daily. The dose will be titrated on V2 based on the adequacy of pain relief and tolerability. If pain intensity during V2 is < 4 on a scale of 0-10, the dose of duloxetine dose will be 30mg daily throughout the study. If pain intensity is ≥ 4 on a numeric rating scale of 0-10 and duloxetine is well tolerated, the daily dose will be increased to 60mg once daily. If the subject does not tolerate the initial dose of duloxetine, he/she will be dropped out of the study and replaced by another patient.

Active Comparator: Pregabalin and tramadol

Drug: Tramadol

Drug: Pregabalin

The initial dose of pregabalin (Lyrica, Pfizer, USA) will be 75mg twice a day. The dose will be titrated on V2 based on the adequacy of pain relief and tolerability. If pain intensity during V2 is < 4 on a scale of 0-10, the initial dose of pregabalin dose will be continued. If pain intensity is ≥ 4 on a numeric rating scale of 0-10 and pregabalin is well tolerated, the daily dose will be increased to 150mg twice a day. If the subject does not tolerate the initial dose of pregabalin, he/she will be dropped out of the study and replaced by another patient.

Outcome Measures

Primary Outcome Measures

Concentration of O-desmethyltramadol [3 weeks]

Secondary Outcome Measures

Plasma 5-HT concentration [baseline, 1, 2 and 3 weeks]
Platelet function [baseline and 3 weeks]
Pain intensity [daily for 3 weeks]
Pain intensity will be rated by the subjects on a numerical 11-point rating scale of 0-10 (NRS) with 0 meaning "no pain" and 10 meaning "pain as bad as you can imagine". The subjects will be asked to rate pain intensity on the average over the past 24 hours. Pain intensity will be recorded at each study visit and daily by the subject using a pain diary.
Use of rescue medication [1,2 and 3 weeks]
Behavioral serotonergic effects [1, 2 and 3 weeks]
Concentration of O-desmethyltramadol [baseline, 1 and 2 weeks]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 70 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Chronic (≥ 6 months) neuropathic pain due to postherpetic neuralgia or diabetic polyneuropathy
Pain intensity ≥ 4 on a numerical scale of 0-10
Informed consent

Exclusion Criteria:

Clinically significant abnormalities in laboratory screening
Pregnancy
Depression
Use of strong opioids (morphine, oxycodone, fentanyl, hydromorphone, methadone)
A previous history of intolerance or allergy to the study drugs or to related compounds and additives
Existing or history of seizures, haematological disorders, clinically significant renal, hepatic, respiratory, cardiac or psychiatric disease, dementia, drug allergy
Previous or present alcoholism, drug abuse, psychological or other emotional problems or cognitive impairment that are likely to invalidate informed consent or limit the ability of the subject to comply with protocol requirements
Concomitant drug therapy known to cause significant enzyme induction or inhibition of CYP 1A2, 2D6, 3A4, 2B6, drugs metabolised by CYP2D6 enzyme, antidepressants, MAO-inhibitors, non-steroidal anti-inflammatory analgesics.