Medicated lidocaine patches help reduce postherpetic neuralgia pain, and in turn improve sleep quality and overall perception of quality of life in patients with the debilitating condition.
The results of the 8-week, open-label study were published in the journal Pain Management.
The 8-week run-in study was part of a larger double-blind, placebo-controlled, multicenter phase 3 trial, and included 265 patients (42.6% male) aged 50 years or older with postherpetic neuralgia for at least 3 months post-rash healing. Patients were enrolled until exit due to lack of pain relief. Changes in quality of life were measured with the Chronic Pain Sleep Inventory, Short-Form 36 health survey, and Short-Form McGill Pain Questionnaire.
Patients applied up to 3 5% lidocaine (700mg) patches for up to 12 hours per day, depending on the size of the painful area. Patches were applied anytime when pain returned or increased, however a patch-free period of 12 hours was required. No topical analgesics were allowed.
Mean pain intensity at baseline was 5.9 ± 1.4, with most patients complaining of problems falling asleep, requiring sleep medication, or being awakened by pain at night or in the morning. Approximately 60% of patients were taking concomitant medications for PHN, and a large amount had comorbidities, including vascular, cardiac, and metabolic disorders.
Overall, approximately 50% (137 of 265) of patients achieved at least moderate pain relief with the medicated patches and were in turn categorized as responders. The proportion of patients who “usually or always” had trouble falling asleep decreased to 14.3% after week 1 of treatment and 9.2% after 4 weeks, from 34.3% at baseline. Of the patients who “never or rarely” had trouble falling asleep but “usually or always” took sleep medication (22.5%), those needed medication fell to 17% and 16.1% after 1 and 4 weeks of treatment, respectively. Those who “usually or always” complained of being awakened by pain during the night fell to 11.5% and 5.6% after 1 and 4 weeks of treatment, respectively, from 28.5% at baseline. Comparable results were seen for patients who reported being awakened by pain in the morning.
For assessments of quality of life, mean scores were positive or increased across all categories after baseline, with the greatest improvements seen in body pain, emotional role, and social functioning. Fewer patients reported moderate/severe pain and more reported none/mild pain after treatment with lidocaine patches.
Based on the Short-Form McGill Pain Questionnaire, 93% and 54% considered their pain to be discomforting or distressing or worse at baseline, respectively. After up to 8 weeks of treatment, 62% of patients reported their pain level as discomforting or worse and 19% reported pain as distressing or worse. All reports of pain types, including hot-burning, tender, stabbing, aching, and exhausting pain were reduced.
Overall, results showed that 5% lidocaine patches provide additional benefits beyond pain relief for patients with postherpetic neuralgia, suggesting that treatment with the medicated patches may help reduce the burden of the condition.