Findings from animal studies suggest that a combination of isovaline and anesthetic agents may preclude the need for opioid medications—and their attendant adverse effects—for procedural sedation and anesthesia. The results are reported in Anesthesia & Analgesia. Isovaline is a unique type of analgesic that acts on one specific type of neuroceptor: the GABAB receptors. Because it doesn't cross the "blood-brain barrier," isovaline acts only on peripheral neuroreceptors outside the central nervous system. A research team from the University of British Columbia, Vancouver, constructed a series of mouse studies to evaluate isovaline as an opioid alternative for general anesthesia. The mice were administered propofol in combination with either isovaline or the opioid fentanyl.
The team found that propofol alone produced hypnosis, but didn't block pain responses, while the addition of isovaline "resulted in loss of consciousness and immobility to noxious stimuli." The same result was achieved with the combination of propofol and fentanyl, but with the attendant risk of respiratory depression. The study concluded that because of its lack of effect on the central nervous system, isovaline might be considered as a valid alternative for general anesthesia and procedural sedation.
Read more about GABAB here.
Read more about the findings here.
Editorial commentary on the findings may be read here.
The study abstract may be read here.