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

Inclusion Criteria: * Participants having painful symmetric neuropathy (a disturbance in the function of the brain or spinal cord that may affect the nerves and muscles of the body) in the lower limbs applicable to both of the following conditions: decreased sensation of leg to monofilament, none or decreased ankle reflexes or decreased vibratory sensation and pain symptoms such as numbness (loss of sensation), tingling, paresthesia (a skin sensation, such as burning, prickling, itching, or tingling, with no apparent physical cause), burning, shooting pain, stabbing or lancinating (characterized by a sensation of cutting, piercing, or stabbing) pain * Participants having painful diabetic neuropathy in the lower limbs for 3 months before randomization * Participants diagnosed with Type ll diabetes and stable blood sugar level controlled with an oral medication, insulin or diet therapy for 3 months before randomization * Participants with glycated hemoglobin (HbA1c) less than or equal to 10 percent * Participants with pain intensity score of greater than or equal to 4 on numeric rating scale (NRS) for the last 48 hours Exclusion Criteria: * Participants who have previously experienced failure of tramadol treatment or have discontinued tramadol administration due to adverse event * Participants who have received the prohibited medication before randomization (e.g., capsaicin, use of systemic steroids, steroid or local anesthetic injections, tramadol HCl or tramadol combination, gabapentin, opioid analgesics, antidepressants, anticonvulsants, alpha-lipoic acid, acupuncture, COX-2 selective inhibitors, long-acting NSAIDs, opioid analgesics, sedative-hypnotics, muscle relaxants, anxiolytics, antipsychotics, TENS, short-acting non-opioid analgesics) * Participants with neuropathic pain caused by other reasons (e.g., alcohol abuse, connective tissue disease, toxic exposure, infection, neoplasm, ischemia) * Participants suffering from painful diabetic neuropathy over 10 years * Participants with physical damage or disease which may cause abnormal absorption, excessive accumulation, metabolism or excretion disorder of the study medication