A Study to Compare Safety and Efficacy of Tramadol Hydrochloride/Acetaminophen With Gabapentin in Participants With Diabetic Neuropathy

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.

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.