Heroin slows down activity in the brain and spinal cord. What this means is that it impairs cognitive performance and causes respiratory difficulties (which can slow down or even stop). The individual may experience a dip in temperature and blood pressure as well as an erratic heartbeat. The individual may go into a coma or lose consciousness. Naloxone can be administered by paramedics, loved ones, or anybody else who comes into contact with a heroin addict. Over-the-counter sales of naloxone were postponed until February 2016. If you want further information, you should consult your pharmacist.