Localized Neuropathic Pain: Topical Treatment Versus Systemic Treatment

Safety, Efficacy and Patient Acceptability of Topical Treatment Versus Systemic Treatment: a Randomized, Multicentre, Comparative Pragmatic Trial in Adult Patients Suffering From Diverse Localized Neuropathic Pain (LNP) Syndromes

Evaluation of topical treatment with lidocaine 5% patch (daily administration) or capsaicin 8% patch (periodic administration - upon reoccurrence of pain symptoms) in adult patients suffering from localized neuropathic pain (LNP) across a wide variety of etiologies, with a duration between 1 and 24 months (subacute to chronic neuropathic pain (NP)).

A multicentre, randomized, open-label comparative trial evaluating topical treatment options versus oral systemic treatment in adult patients suffering from localized neuropathic pain (LNP) syndromes. A wide variety of peripheral neuropathic pain syndromes will be included such as post-herpetic neuralgia (PHN), post-surgical NP/post-traumatic NP/scar pain, post-amputation NP, post-radiation therapy NP, complex regional pain syndrome (CRPS) type 1. In contrast to most (or even all) commercial clinical studies we will not limit the inclusion to one or two distinct neuropathic pain syndromes such as post-herpetic neuralgia (inclusion based on etiology of the neuropathic syndrome). In this pragmatic trial we will however include all patients suffering from a clinical neuropathic syndrome with distinct clinical features such as hyperalgesia/allodynia, presence of spontaneous positive sensory phenomena and lasting for more than 3 months without making any exclusion based on etiology. Initial pain intensity indicates the presence of either moderate or severe pain in these adult patients (NRS 4/10).

Patients eligible for inclusion in this study must fulfil all of the following criteria:

• Subjects should be capable of giving their informed consent with sufficient knowledge of the Dutch, French or German language;
• Males and females, 18 years and older;
• Be assessed as suffering from moderate to severe neuropathic pain across the screening process with pain intensity (numeric rating scale - NRS) ≥ 4/10,
• At the time of screening pain symptoms have to be present for at least one (1) month, with a maximum of 24 months;
• Sensory disturbances present in the skin area of maximal pain;
• At the time of screening pain is clearly related to the presence of a localized neuropathic pain syndrome.
• Male or female patients of child producing potential* must agree to use contraception or take measures to avoid pregnancy during the study and until after the final treatment;
• Women can only be included after negative pregnancy test;

Exclusion Criteria:

• Age < 18;
• Pregnant and breastfeeding women;
• Infection in the painful skin region;
• Poorly healed or non-healed wound or scar in the painful skin region as well as presence of cutaneous abnormalities (non-intact skin barrier) within the painful skin region related to dermatological conditions;
• Known and/or strong suspicion of allergy to the study medication, known skin disorder (resulting in disruption of the normal skin barrier);
• Previous treatment with any of the three medications included in the study protocol for the same painful area within the last 12 months at the time of screening;
• Risk of heart failure and/or renal failure.