A Study With Lido-Patch and Placebo Plaster in Patients Suffering From Postherpetic Neuralgia (PHN)

Inclusion Criteria for the Run-in Phase:

• Adult participants, male and female, with a minimum age of 50 years at screening.
• Participants who had postherpetic neuralgia (PHN) for at least 3 months after healingof a herpes zoster skin rash.
• Pain score of at least 4, based on an 11-point numerical rating scale (NRS) (scale of 0-10), at the screening and enrolment visit. The pain assessment is the participant'srecall of the pain intensity since the previous week.
• Written informed consent given. Randomization Criteria:
• Participants must be regularly (minimum every second day) using the Lido-Patch forcontrol of pain in the last 4 weeks of the run-in phase. The participant must wait forpain to increase before applying a new patch.
• The participants' average daily pain intensity (with patch on) must be 7 or less on an 11-point NRS (scale of 0-10), and must increase during the phases when a patch is notworn, during Week 8 of the Run-in Phase.
• Before randomization, the participant must have an average relief with Lido-Patch of "moderate" or better, on a 6-item scale (worse, no pain relief, slight, moderate, alot, complete) during Week 8 of the Run-in Phase.

Exclusion Criteria:

• Participation in another study of investigational drugs or devices parallel to, orless than 30 days before screening, or previous participation in this study.
• Known to or suspected of not being able to comply with the study protocol.
• Any clinically significant condition that would, in the investigator's opinion,preclude study participation for instance alcohol, medication or drug dependency,neurotic personality, psychiatric illness, epilepsy or suicide risk.
• Pregnancy or nursing mother.
• Woman in childbearing age without satisfactory contraception.
• Hypersensitivity to lidocaine or amide-type local anesthetic drugs.
• Active herpes zoster lesion or dermatitis of any origin at the affected site with PHN.
• Evidence of another cause for pain in the area affected by herpes zoster in additionto PHN, such as lumbar radiculopathy, surgery or trauma, if this could confoundassessment or self-evaluation of the pain due to post herpetic neuralgia.
• Participants who had neurological ablation by block or neurosurgical intervention forcontrol of pain in PHN.
• Participants using topically applied analgesic compounds on the PHN affected area.
• Presence of other severe pain that could confound assessment or self-evaluation of thepain due to PHN.
• Participants with severe hepatic disorder and/or alanine or aspartate aminotransferaseequal to or above 3-fold the upper limit of normal (ULN).
• Participants with severe renal disorder and/or increased serum creatinine equal to orabove 1.5-fold the upper limit of normal (ULN).
• Participants who are undergoing active treatment for cancer, are known to be infectedwith the human immunodeficiency virus (HIV), or being acutely and intensivelyimmunosuppressed following transplantation.