Looks like a ketamine OD. This is why pain medication is injected via the intramuscular route, not directly into a vein. It titrates the dose and prevents instant uptake like this. The only time you give anything that strong via the IV route is with an IV pump, which dilutes the dose in enough saline solution to control how fast it enters the system.
You seem to know your way around death and crime scenes. Go to Akyan's Some Dead Chinese WOmen thread, and provide us with some of your opinions on the cause of death?