Conditions: Diabetic Neuropathy
Keywords: Diabetic neuropathy Ultracet Tramadol hydrochloride Acetaminophen Gabapentin
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 162
Healthy volunteers: no

Brief summary:
The purpose of this study is to evaluate the effectiveness and safety of tramadol hydrochloride (HCl) 37.5 miligram (mg)/acetaminophen 325 mg compared to gabapentin in participants with diabetic neuropathic (nerve disorder caused by diabetes mellitus) pain.

Detailed description:
This is an open-label (a medical research study in which participants and researchers are told which treatments the participants are receiving, "unblinded"), multi-center and randomized (study drug is assigned by chance) study to compare the effectiveness and safety of tramadol HCl 37.5 mg/acetaminophen 325 mg with gabapentin in participants with diabetic neuropathy. The study will consist of 4 periods: Screening period (up to Day -14), Randomization period (Day 1), Dosage adjustment period (Day 15) and Maintenance period (Day 43). The participants will be randomly assigned to 1 of the 2 treatment groups: tramadol HCl 37.5 mg/acetaminophen 325 mg or gabapentin. Tramadol Hcl/acetaminophen group will receive 1 tablet for 3 days, then 1 tablet twice daily for 4 days followed by 1 tablet thrice daily for next 7 days. If there is no pain relief, the dosage can be increased up to 8 tablets per day for Day 15 to 28, and then the increased dosage will be maintained for Day 29 to 42. Gabapentin group will receive 300 mg on Day 1, 300 mg twice daily on Day 2, and 300 mg thrice daily for Day 3 to 7. Then for Day 8 to 14, participants will receive 300 mg in the morning, 300 mg in the midday and 600 mg in the evening. If there is no pain relief, gabapentin can be increased up to 3600 mg per day for Day 15 to 28, and then the increased dosage will be maintained for Day 29 to 42. Primarily, efficacy will be evaluated by pain intensity using numeric rating scale (NRS). Participants' safety will be monitored throughout the study.

Arms:
arm 1: Participants will receive 1 tablet containing tramadol HCl 37.5 milligram (mg) and acetaminophen 325 mg once daily, at bed time on Days 1 to 3, 1 tablet twice daily on Days 4 to 7 and 1 tablet thrice daily on Day 8 to 14. If there is no pain relief, the dosage can be increased up to 8 tablets per day for Days 15 to 28. The increased dose will be maintained for Days 29 to 42. arm 2: Participants will receive Gabapentin 300 mg once daily at bed time on Day 1, 300 mg twice daily on Day 2 and 300 mg thrice daily on Day 3. Gabapentin 300 mg will be administered twice daily (in the morning and midday) and gabapentin 600 mg in the evening on Day 8 to 14. If there is no pain relief, the dosage can be increased up to 3600 mg per day for Days 15 to 28. The increased dose will be maintained for Days 29 to 42.

Interventions: intervention 1: Tramadol hydrochloride/ Acetaminophen intervention 2: Gabapentin
Intervention descriptions: intervention 1: Participants will receive 1 tablet containing tramadol HCl 37.5 milligram (mg) and acetaminophen 325 mg once daily, at bed time on Days 1 to 3,. 1 tablet twice daily on Days 4 to 7 and 1 tablet thrice daily on Day 8 to 14. If there is no pain relief, the dosage can be increased up to 8 tablets per day for Days 15 to 28. The increased dose will be maintained for Days 29 to 42. intervention 2: Participants will receive Gabapentin 300 mg once daily at bed time on Day 1, 300 mg twice daily on Day 2 and 300 mg thrice daily on Day 3. Gabapentin 300 mg will be administered twice daily (in the morning and midday) and gabapentin 600 mg in the evening on Day 8 to 14. If there is no pain relief, the dosage can be increased up to 3600 mg per day for Days 15 to 28. The increased dose will be maintained for Days 29 to 42.

Protocol document: