Chronic Pain Management after Herniorraphy

INTERVENTION: Trade Name: ‐ Lyrica 75 mg hard capsules Pregabalin ‐ Lyrica 150 mg hard capsules Pregabalin ‐ Lyrica 300 mg hard capsules Pregabalin Product Name: Lyrica® Pharmaceutical Form: Capsule, hard Pharmaceutical form of the placebo: Capsule, hard Route of administration of the placebo: Oral use CONDITION: Patients suffering from chronic pain of neuropathic character after open hernia repair. ; MedDRA version: 8.1 Level: LLT Classification code 10049475 Term: Chronic pain PRIMARY OUTCOME: Main Objective: The primary objective of this study is to investigate whether pregabalin at a dose of 150‐600 mg in two divided doses a day reduces pain in patients with chronic neuropathic pain after herniorraphy. This research question will be answered by testing of the following hypothesis:; ; ‐ Treatment with pregabalin (150‐600 mg dose) results in a statistically significant improvement in endpoint mean pain score of = 1,2 during 8 weeks follow‐up relatively to treatment with placebo Primary end point(s): The primary outcome is the mean 11‐point numerical pain rating score in both treatment groups at baseline and follow‐up. Secondary Objective: The secondary objective; ; ‐ The difference in quantitative sensory testing (QST) thresholds between the painful inguinal area and the normal contra‐lateral side in patients of which the chronic pain is treated by pregabalin is clinical significant greater than the difference found in patients of which the chronic pain is treated by placebo; INCLUSION CRITERIA: 1. History of unilateral inguinal herniotomy 2. Establishment of neuropathic character of chronic pain by means the LANSS painscore and DN4 score 3. Abnormal sensitivity (allodynia, dysesthesia, hypoesthesia or dysesthesia) in or around the incisional area 4. Duration pain = 3 months 5. Gender: Male 6. Medial or lateral inguinal hernia 7. Age = 18 years 8. Description III or IV of pain interfering with daily activity 9. VAS score = 40 mm on Vas scale on which they indicate ‘how unpleasant or disturbing the worst pain was that they had today’ 10. Informed consent (addendum V) Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18‐64 years) yes F.1.2.1 Number of subjects for this age range F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range