Capsaicin 8% patch Qutenza treatment in non-freezing cold injury (NFCI): a clinical trial of repeated patch applications for pain relief and nerve regeneration
Non-freezing cold injury, NFCI (Trench Foot).
This study is a randomized, double-blind, placebo-controlled clinical trial (RCT) with baseline and post-treatment sensory tests and skin biopsy after repeated treatments with a Capsaicin 8% patch (Qutenza). Participants will be randomly allocated with a 1 to 1 ratio to either receive a 30-minute capsaicin 8% patch (Qutenza) application to both feet up to the distal calf (Capsaicin treatment group, number of subjects = 27) while continuing to take their usual medications as part of their Standard of Care (SOC) or to receive placebo patches (with no capsaicin) plus SOC (Placebo group, number of subjects = 27) every 3 months for 1 year. Randomization will be performed via OpenClinica, an electronic platform, by the Imperial Clinical Trials Unit. The Pharmacy will be informed of the randomisation treatment code allocation by the Imperial Clinical Trials Unit. Neither the researchers nor the participants in the study will know whether the patch applied is the Capsaicin 8% patch or the placebo patch.
1. Military service personnel aged 18-60 years with non-freezing cold injury (NFCI) resulting in painful neuropathy 2. History of distal symmetric sensory polyneuropathy affecting feet for at least 8 weeks, confirmed on clinical examination and/or sensory testing and assessed on the 11-point pain intensity numerical pain rating scale (NPRS). 3. Patients with a history of pain intensity equal to or greater than 4 NPRS points are eligible to participate. 4. The use of systemic analgesics to relieve pain including anti-depressants, anticonvulsants, opioids, salicylates, paracetamol, and non-steroidal anti-inflammatory drugs (NSAIDs) will be permitted, providing any changes are recorded for the entire duration of the study
1. Participating in another clinical trial or who has done so within 30 days before screening 2. Additional medical condition or illness that, in the opinion of the Investigator, would interfere with study compliance and/or impair the patient's alcohol or drug abuse) within the previous six months before enrolment 3. A history of severe allergies or multiple drug allergies and/or reported hypersensitivity to capsaicin 4. Other conditions that may lead to neuropathic pain or hypersensitivity e.g. diabetes, and HIV 5. Topical anaesthetic or capsaicin applications, or history of previous treatment with the Capsaicin 8% patch (to minimise unblinding) 6. Pregnant or nursing mothers will not be included in this study; relevant history will be taken. A pregnancy test will be performed and patients who are pregnant will be excluded from the study.