In the past few years, a new public health crisis has been identified. Deaths from the direct effect of opioid drugs are escalating. Many new potent opioids, including fentanyl and its analogues, are available on the streets. These may be used as substitutes for heroin and cocaine, or found as contaminants of these drugs. Even those who use opioids regularly may not be tolerant to these relatively potent opioids, resulting in unexpected overdoses. The opioid known as carfentanil is an example of a fentanyl analogue.
Opioids typically cause a person to have a depressed level of consciousness, a decreased respiratory rate and small or pinpoint, pupils. With increasing intoxication, respirations can stop, and further injury from hypoxia, including coma and cardiac arrest, can occur.
Most pharmaceutical opioids, heroin and fentanyl, should respond to usual doses of naloxone. The desired response to naloxone should be establishment of adequate respirations, to have an O2Sat > 90% and a pCO2 < 45 mmHg. The patient does not need to be fully awake and alert. With naloxone dosing health-care providers have always been taught to "start low and go slow" to prevent acute opioid withdrawal. Although uncomfortable, opioid withdrawal is generally not life threatening. OPC has guidelines for pre-hospital and hospital opioid resuscitation here.
Treatment for the opioid overdose patient currently consists of supportive care and the antidote naloxone. Naloxone should now be available in Canada from pharmacies without prescription. It may be obtained at participating pharmacies by asking the pharmacist for the medication. In Ontario, most pharmacies will provide two vials of naloxone (0.4 mg per vial), two syringes and needles, and instructions for its use. Various other public health departments also have naloxone distribution programs that may provide more doses of naloxone. Eventually, an intranasal naloxone form may be available (4.0 mg naloxone per syringe). OPC has guidelines for the lay-rescuer here.