Question: What are the so-called PAMORA agents?
Answer: The cited reference notes “Peripherally acting μ-opioid receptor antagonist” agents (PAMORA’s) are newer agents that specifically block the peripheral effects of opioids on μ-opioid receptors in the enteric nervous system to treat OIC (opioid induced constipation). It has been suggested that up to 50% of patients with OIC may benefit from treatment with a PAMORA, however, PAMORA resistant constipation may be found in patients with other etiologies which may include medications, advanced age, immobility or advanced illness. Currently two agents are FDA-approved for the treatment of opioid-induced constipation. Naloxegol (Movantik®) was approved in 2014 for the treatment of opioid-induced constipation in adult patients with chronic non-malignant pain. Methylnaltrexone (Relistor®) was initially approved in 2008 for the treatment of opioid-induced constipation in adult patients with advanced illness who are receiving palliative care, when response to laxative therapy was not sufficient, and expanded in 2014 to include the treatment of opioid-induced constipation in adult patients with chronic, non-malignant pain. The use of PAMORAs are being incorporated within guidelines for management of constipation in patients receiving opioids.” (Frydrych V. https://medicaid.utah.gov/pharmacy/ptcommittee/files/Criteria%20Review%20Documents/2015/2015.12%20PAMORA%20Drug%20Class%20Review.pdf; accessed June 2017)