A new CDC guideline for prescribing opioids for pain recently became available. Nonopioid drugs for pain were reviewed in a previous issue.

Use of nonopioid drugs for pain was reviewed in a previous issue. For many types of moderate to severe acute pain, acetaminophen and/or an NSAID may be as effective as an opioid. Immediate-release formulations of full opioid agonists should generally be used for acute pain that is severe enough to require treatment with an opioid. Use of extended-release or long-acting opioid formulations initially and treatment durations >1 week have been associated with an increased risk of unintended long-term use.

The FDA has approved the opioid receptor antagonist naldemedine (Symproic – Shionogi) for treatment of opioid-induced constipation (OIC) in adults with chronic noncancer pain. Naldemedine is the third oral peripherally-acting mu-opioid receptor antagonist (PAMORA) to be approved for this indication; naloxegol (Movantik) and methylnaltrexone (Relistor) were approved earlier.

The FDA has approved naloxegol (Movantik – AstraZeneca), a pegylated derivative of the opioid antagonist naloxone, for oral treatment of opioid-induced constipation in adults with chronic noncancer pain. It is the only oral opioid antagonist approved for this indication in the US.

The FDA has approved use of lubiprostone (Amitiza) for treatment of opioid-induced constipation in adults with chronic non-cancer pain. The drug was previously approved for chronic idiopathic constipation and irritable bowel syndrome with constipation.

Pain can be acute or chronic. Chronic pain has been broadly classified into two types: nociceptive and neuropathic. Nociceptive pain can be treated with nonopioid analgesics or opioids. Neuropathic pain is less responsive to opioids; adjuvant medicines such as antidepressants and anticonvulsants are often used to treat neuropathic pain. Combining different types of analgesics may provide an additive analgesic effect without increasing adverse effects.

The FDA has approved the marketing of alvimopan (Entereg - Adolor/GlaxoSmithKline), a selective muopioid receptor antagonist, for oral treatment of postoperative ileus after bowel resection. The only other drug in this class available in the US is subcutaneously injected methylnaltrexone (Relistor), which is approved for treatment of opioid-induced constipation in patients with advanced illness receiving palliative care.

The FDA has approved subcutaneous injection of methylnaltrexone (Relistor - Wyeth/Progenics), a selective mu-opioid receptor antagonist, for treatment of opioid-induced constipation in patients with advanced illness (such as incurable cancer or end-stage chronic obstructive pulmonary disease) who are receiving palliative care.