Slide 1: The drug morphine gets its name from which fictional figure?

Slide 2: Morpheus, the Greek god of dreams. According to Greek mythology, Morpheus had the ability to send images through dreams. As such, he often acted as the messenger of the gods. If dozing in Morpheus’ arms, one was guaranteed a sound, peaceful slumber – not unlike the drowsy effects observed with morphine, its pharmacological namesake.

Slide 3: Morphine is chiefly used for its analgesic properties, which are mediated by the miu opioid receptor. This receptor is also responsible for the drug’s concomitant sedative effects. However: evidence from animal models suggests that morphine’s sleepy side effects might be avoided by mimicking orexins, neuropeptides responsible for hypothalamus-mediated sleep-wake cycles.

Slide 4: In a recent study, investigators dosed rats with morphine alongside an accompanying orexin agonist (or orexin “mimic”). The result? EEG analyses of the orexin-treated rats suggested that this group achieved analgesia – without sedation.


  • Pathan H, Williams J. Basic opioid pharmacology: an update. Br J Pain. 2012 Feb;6(1):11-6. PMID 26516461
  • Toyama S, Shimoyama N, Tagaito Y, et al. Nonpeptide Orexin-2 Receptor Agonist Attenuates Morphine-induced Sedative Effects in Rats. Anesthesiology. 2018 May;128(5):992-1003. PMID 29521652

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