“…Pentazocine (PTZ) is widely used for pain control in Japan, acts on central μ-and κ-opioid receptors, 6,7) and produces analgesic effects by inhibiting the stimulus conduction system. 8,9) As a result, morphine-like side effects, such as nausea, dizziness, headache, insomnia, increased blood pressure, and decreased respiratory rate, [10][11][12] are observed. Moreover, fatal PTZ overdose and abuse have been reported, and some studies revealed that the entry point for people who fall into inappropriate self-injection is medical in origin.…”