PCOL3012 Lecture Notes - Lecture 9: Naloxone, Fentanyl, Remifentanil
Document Summary
Drug addiction: has become a significant social and medical problem. In 2016, 42,000 americans died of an opioid overdose, which has increased from about 4000 in 1999. In australia there are 75,000 heroin addicts and approx. Morphine overdoses is most often due to suffocation with depression of the respiratory centre causing an inability to breath. Many attempts to synthesize compounds that have the same analgesic effects but without the side effects or addiction properties. Opioid receptors are gpcr"s: delta- does not have much therapeutic effect. Opioid receptor structure: morphine binds to a cavity at the extracellular edge of the receptor, opioid binds in between transmembrane domains. Cns drugs slightly more lipiophilic than other drugs. Morphine is a weak base: only the unionized form can cross the bbb. At ph 7. 4 (blood) morphine is 86% ionised and 14% unionised. Normorphine: 25: they have similar affinity for their receptor.
