Establishing an animal model for National Acupuncture Detoxification Association (NADA) auricular acupuncture protocol.

The use of opioids in the treatment of chronic pain has increased dramatically in the past few decades making them one of the most commonly prescribed medications in the US. However, long-term use of opioids is limited by development of tolerance (decreased antinociceptive efficacy) and opioid-induced hyperalgesia - paradoxical sensitization to noxious (hyperalgesia) and non-noxious (allodynia) stimuli. Novel adjunctive therapies are needed to increase the efficacy and prolong the duration of action of opioids in chronic pain treatment. Acupuncture is often used as an adjunct therapy for the treatment of symptoms induced by non-clinical use of opioids. The National Acupuncture Detoxification Association (NADA) auricular acupuncture protocol is the most common form of acupuncture treatment for substance abuse. The standardized, easy to use and virtually painless procedure make it an attractive complementary treatment option for patients suffering from opioid-induced adverse effects. Clinical trials designed to test the efficacy of the NADA protocol yielded contradictory results. The mechanism by which NADA acupuncture could serve as a successful treatment remains unknown. Therefore, establishing an animal model of NADA acupuncture can provide a tool for investigating the efficacy and cellular mechanisms of NADA treatment. Previous studies have shown that repeated morphine administration in rodents can produce locomotor sensitization and reduce analgesic potency of a challenge dose of morphine, indicating development of morphine tolerance. Here we show that NADA acupuncture treatment can both reduce morphine-induced locomotor sensitization and prevent the development of morphine tolerance in rats, thus validating a new model for NADA acupuncture studies. Our data provides support for evidence-based use of NADA acupuncture as a new adjunctive approach that can potentially improve the side-effect profile of morphine and other prescription opioids.