Post treatment with naloxone after microinjections of NSAIDs into the DH results in a significant decrease in TF latency for the first day for clodifen (A), ketorolac (B), and xefocam (C), respectively (P < 0.001). On the second and third days, there are generally trend effects for all three non-opioid analgesics. The same decreases of latencies are observed in HP test for clodifen (D) (P < 0.01), ketorolac (E) (P < 0.001), and xefocam (F) (P < 0.001), respectively. Number of rats N = 5/groups. *- P < 0.05, **- P < 0.01, ***- P < 0.001.