However, since a significant fraction (up to 60%) of opioid analgesia can be mediated by opioid receptors on peripheral sensory neurons, particularly in inflammatory conditions such as arthritis, traumatic or surgical pain, MNTX may increase pain under such circumstances.
The statement underscores an essential aspect of opioid analgesia, which is that a considerable proportion (up to 60%) of pain relief can be attributed to opioid receptors on peripheral sensory neurons, especially in inflammatory conditions like arthritis or post-traumatic/surgical pain. This implies that methoxyflurane (MNTX) may intensify pain under such circumstances.