Naloxegol for Opioid-Related Gastroparesis

Medicines can delay gastric emptying and produce similar symptoms to gastroparesis. In particular, narcotic analgesics, can produce a gastroparesis picture, by delaying gastric emptying. The slowing effect of opioids on gastric, small bowel, and colonic motility has been well characterized. Unfortunately, many of these patients cannot stop their pain medications due to their underlying condition, such as back pain, fibromyalgia. On top of this, the narcotics can reduce the effectiveness of prokinetics agents used to treat gastroparesis, such as metoclopramide and domperidone. At this time, there is no good treatment for gastroparesis, especially for opioid-related gastroparesis. Data suggests a relationship between opioid use and decreased gastric motility. Literature suggests that peripherally acting opioid agonist may provide relief in the instance of GI dysfunction (Holzer 2007). Movantik (Naloxegol) is an opioid agonist specifically designed to work outside of the central nervous system. Movantik (Naloxegol) can alleviate the adverse effects associated in chronic pain patients on opioid treatment - reduction of the undesired peripheral effects of opioids without disrupting analgesic effects. The use of Movantik (Naloxegol) has the potential to improve gastric dysmotility while preserving pain relief of the opioid analgesic. The objective of this study is to evaluate the effects of naloxegol in opioid-related gastroparesis. This will be a randomized, double-blind study comparing Movantik 25 mg to placebo. The dose of Movantik is the dose that is currently FDA approved for opioid-induced constipation. The four-week study period is the duration of the phase 2b studies for Movantik for opioid-induced constipation in which the response rates were 60% and 35% with active treatment and placebo (Chey 2015). The investigators have included a unique aspect of this study to better balance the benefits for patients participating in this randomized double-blind study in which half the patients receive a placebo agent. All patients in the treatment group and the placebo group will be invited to participate in the 4-week open-label extension for this study. This also serves to study the duration of the potential favorable effects of Movantik (Naloxegol) in this patient population as well as offering an extended time period to assess safety and tolerability.