“…Therefore, sufficiently high doses of ATP infusion over a long period of time (e.g., 2-3 h) may provide better pain relief than shorter infusions (e.g., 1 h or less). It is noteworthy that in a limited number of cases, permanent abolition of spontaneous pain and allodynia can be achieved with a single adenosine or ATP infusion [10,21,50,52,53,67], and that repeated adenosine or ATP infusions provide progressively improved pain relief in some responders [51,73]. K, ketamine; L, lidocaine; ATP, adenosine triphosphate Positive response to a drug was defined as more than 50% reduction in the Visual Analogue Scale for spontaneous pain a V, C, T, L, and S indicate trigeminal, cervical, thoracic, lumbar, and sacral regions, respectively b The response to ATP was correlated with the response to ketamine but not with the response to lidocaine Modified from [66], with permission, by adding data from three cases including one in [21] Positive drug response Fig.…”