A method of producing analgesia in a mammal is provided by rotational (alternating) intrathecal administration to the mammal of a pharmaceutically effective dose of at least one opioid receptor agonist, such as a μ-, δ-, or κ-opioid receptor agonist for a first period of time, followed by intrathecal...http://www.google.es/patents/US7737118?utm_source=gb-gplus-sharePatente US7737118 - Rotational intrathecal analgesia
