Pain News & Notes: May 2012

As part of our continued effort to provide pain professionals with the resources they need, PainLive presents summaries of ongoing research and news in a broad range of pain management topics.

FDA Advisory Committee Recommends Allowing Research to Resume on Promising New Class of Pain Medications

Promising new agents for breakthrough cancer pain include the anti-nerve growth factor drugs (anti-NGF) that are currently in development. The FDA had halted their development because of cases of joint destruction and osteonecrosis associated with their use, but the FDA Arthritis Advisory Committee recently voted to allow research in this area to continue and for Janssen, Pfizer, and Regeneron to resume their respective clinical trials, saying they had a role in the management of metastatic cancer pain (http://bit.ly/H8qoiM).

Methylnaltrexone for the Treatment of Opioidinduced Constipation in Critical Care Patients

Opioid-induced constipation is a common problem among patients in the ICU, but laxative therapy is often ineffective at restoring gastrointestinal motility. Researchers recently compared conventional rescue therapy with subcutaneous methylnaltrexone (MNTX) in 15 critical care patients receiving fentanyl infusions who suffered from opioid-induced constipation within 72 hours of admission to the ICU. They reported that laxation occurred within 24 hours in six of the seven patients treated with MNTX, while occurring in none of the eight patients treated with conventional therapy. Median difference in time to laxation between the two groups was 3.5 days (http://bit.ly/ILEG9h).

Nektar Initiates Phase 1 Clinical Study of Shortacting Opioid for the Treatment of Acute Pain

Nektar Therapeutics recently announced that a clinical trial involving NKTR-192, a novel short-acting mu-opioid analgesic candidate, is underway (http://prn.to/HeX36j). According to a news release from Nektar, the new opioid molecule “is designed to have a short-acting profile with rapid onset of pain relief for the treatment of acute pain. With a reduced rate of entry into the central nervous system (CNS) as compared to other fastacting opioid therapies in preclinical studies, NKTR-192 has the potential to greatly reduce the euphoria that underlies opioid abuse and dependence, as well as other unwanted CNS side effects, such as sedation.”

FDA Reauthorization Bill Includes Provisions Designed to Prevent Pain Medication Abuse

A proposal put forth in the Senate “directs the Department of Health and Human Services and the FDA to undertake a review and make recommendations to better track and promote the safe use of prescription drugs. The recommendations would enhance data collection at the federal level, the coordination and effectiveness of prescription drug monitoring programs at the state level, and provide guidance to health professionals about recognizing and reacting to signs of abuse. The proposal would also require the FDA to reveal within six months how it will review and approve new tamper-resistant products designed to prevent abuse (http://bit.ly/JFHyoi).

New Guidance on Treating Pain in Patients with Substance Use Disorders

In March, the US Substance Abuse and Mental Health Services Administration (SAMHSA) published “Managing Chronic Pain in Adults With or in Recovery from Substance Use Disorders,” an entry in the Treatment Improvement Protocol (TIP) series (http://1.usa.gov/IrvYew) designed to provide clinicians with practical guidance and tools for treating chronic noncancer pain in adults with a history of substance use disorder. The authors of this resource wrote that it “advises clinicians to conduct a careful assessment; develop a treatment plan that addresses pain, functional impairment, and psychological symptoms; and closely monitor patients for relapse.” They also reminded the intended audience (primary care physicians) that “even the best treatment is unlikely to completely eliminate chronic pain, and efforts to achieve total pain relief can be self-defeating.” Therefore, an approach that calls on the skills and knowledge of a team of clinicians, holds patients responsible for managing their own pain, and focuses on patient and caregiver education is recommended.

Although this sounds fairly uncontroversial, and the TIP series in general is a valuable clinical resource, readers are advised to consider the warnings of Pain Management editorial advisory board member and executive director of Pain Treatment Topics (http://pain-topics.org) Stewart Leavitt, MA, PhD, who cautions that this document may also contain “numerous flaws, including biases and misrepresentations of research evidence.” In a detailed review, Leavitt noted that “Where this TIP goes astray is in its biased perspectives and in some of the details, or, in many cases, lack of attention to detail.” Read the whole thing at http://bit.ly/GPXu47.

Study Finds Botox Offers Mild Relief from Migraine

A study published in the April 25, 2012, issue of JAMA (http://bit.ly/IcTyOs) found that, compared with placebo, botulinum toxin A “was associated with a small to modest benefit for chronic daily headaches and chronic migraines but was not associated with fewer episodic migraine or chronic tension-type headaches per month.” The authors performed a literature search and reviewed clinical trials that trials compared botulinum toxin A with placebo or other interventions for headaches among adult patients. They found that treatment with botulinum toxin A was associated with a decrease of about two headaches per month among patients with chronic daily headaches and chronic migraine (more than 15 episodes per month). They found little benefit from botulinum toxin A in patients with episodic (ie, fewer than 15 episodes per month) headache and migraine.

Researchers Continue Search for New Analgesics

A recent article in Genetic Engineering & Biotechnology News (http://bit.ly/HdcOt4) reported on the FDA advisory panel’s decision to allow developers of anti-NGF drugs to resume clinical trials, noting that the panel concluded “there is a role for the ongoing development of NGF inhibitors to manage pain associated with conditions other than osteoarthritis for which there are no agents with demonstrated analgesic effect.” The article includes this information in the context of taking a big-picture look at the current state of analgesic research in a regulatory and clinical environment that is increasingly wary of the downsides of treating pain with opioids. The article reports on the “the increasing recognition of the need for new pain therapeutics,” and provides information about promising early research involving ion cannel modulators, “functionally selective” mu receptor activators, synthetic conolidine, and other targets.