Opioids poisoning

Opiates: are alkaloid found as a natural product in Papaver somniferum (Poppy)- unripened seedpods, which include morphine and codeine. Opioids are naturally occurring, synthetic or semisynthetic drugs that have morphine-like activity. Opioids have narcotic effect i.e. they can induce sleep. They are used clinically for analgesia and anesthesia and are available for oral, inhalational, or parenteral abuse.

• Natural (opiates): include Codeine and Morphine
• Semi-synthetic: Altering the structure of morphine produces many semisynthetic opioids, including Heroin Buprenorphine Hydrocodone Hydromorphone Oxycodone Oxymorphone.
• Synthetic: Diphenoxylate Fentanyl Meperidine Methadone Pentazocine Propoxyphene Tramadol

Pharmacology/pathophysiology
Opioids produce their effects by interacting with specific receptors distributed throughout the central and peripheral nervous systems and in the gastrointestinal tract. Their activity resembles that of the body’s three known endogenous opioid peptides: enkephalins, endorphins, and dynorphins. These endogenous peptides are natural ligands for the opioid receptors.
Opioid-receptor activation results in inhibition of adenyl cyclase activity, activation of receptor-operated K+ currents, and suppression of voltage-gated Ca2+ currents. These effects cause hyperpolarization of the cell membrane, which decreases neurotransmitter release, resulting in less pain transmission.