• Source: Made from acetylation of morphine (a natural opioid, from the poppy papver somniferum)
• Forms: Smoked, sniffed, oral, IV, IM

Epidemiology:

• Greater dependence in males than females
• Older people tend to seak help earlier than younger people

Physiology

Acts as opiods - binds to opiod receptors allowing K to leave and closing Ca channels = cell hyper-polarisation (less signal transmission)

PC

• Intensely pleasurable rush and release of histamine

• Sense of peace and detachment

• Respiratory depression - decreased sensitivity of respiratory centres to CO2

• Cough suppression

• pupillary constriction

• nausea and vomitting

• GI effects - can cause constipation - increased muscle tone and decreased motility