Category: Pain Management

New Study Challenges the Need for Some Post-surgical Opioids

Doctors must carefully weigh the pain relief value of opioids for patients against their potential for misuse and inducing opioid addiction even in patients with no history of substance abuse. Now, a new study challenges current practice by showing the effectiveness of an approach that takes a middle way to giving opioids.

Some 16 million people around the world suffer from opioid use disorder, which can result from opioid administration from surgery and for chronic pain. Opioids are highly addictive, with tolerance reached in days and addiction can occur within a matter of weeks, so there is every incentive to minimise exposure of patients to these effective but potentially dangerous medications.

To investigate the effectiveness of minimising opioid use, a team from Michigan Medicine at the University of Michigan conducted a study with 620 patients who had surgery in hospitals across Michigan, had their anaesthetic usage tracked, and filled in surveys within one to three months following their surgeries. The patients were split equally into two groups.
The first group received pre-surgery counseling emphasising non-opioid pain treatment as their first option. Some patients in this group received small, “just in case” prescriptions, but a third of them didn’t receive any opioid prescription at all after surgery.

The patients in the other group received standard care, that is, receiving the usual amount of opioids prescribed after such operations. The prescriptions received in fact were larger than in the opioid sparing group. Most patients didn’t take all of the pills, which if left lying around could be used inappropriately.

Patients in the two groups had the same surgery: either gallbladder removal, full or partial thyroid removal or hernia repair. However, both groups reported equal levels of quality of life and satisfaction with care when followed-up. Most surprisingly, the opioid-sparing group reported less pain overall.

First author Maia Anderson, MD, a resident in the U-M Department of Surgery, said: “It’s so exciting to think about the potential for opioid sparing postoperative pathways to not only reduce the risk of opioids for our patients, but also to substantially decrease the risk of opioid diversion into our communities.”

Senior author Ryan Howard, MD, Surgical Resident, Michigan Medicine commented: “We know that opioids pose serious risks to patients after surgery. We can protect patients from those risks by reducing or eliminating opioids after surgery. But that idea always raises the concern that patients will have uncontrolled pain and feel miserable. This study suggests that’s not the case – patients who get small opioid prescriptions, or even no prescription, are just as satisfied with their recovery after surgery.”

Source: News-Medical.Net

Journal information: Anderson, M., et al. (2020) Patient-Reported Outcomes After Opioid-Sparing Surgery Compared With Standard of Care. JAMA Surgery. doi.org/10.1001/jamasurg.2020.5646.

New Drug Relieves Rheumatoid Arthritis Pain

A new drug, otilimab, has shown effectiveness in treating rheumatoid arthritis (RA). Otilimab is a human monoclonal antibody which inhibits granulocyte-macrophage colony-stimulating factor (GM-CSF). GM-CSF is a large driver of immune-mediated inflammatory conditions.

The drug is currently being tested on its ability to suppress inflammation, tissue damage and pain in RA sufferers.

A multicentre, dose-ranging trial conducted with the drug. Participants were administered subcutaneous injections with one of five different dosages of otilimab (22.5 mg, 45 mg, 90 mg, 135 mg, or 180 mg) or placebo weekly for five weeks. Thereafter, they received injections once every two weeks for one year. The results showed a rapid reduction in tenderness and swelling, and a very high reduction in pain.

The study was unusual in that it offered an escape arm. It is often difficult to recruit participants when they know they may be receiving a dummy injection, and so if, after 12 weeks the participants  on the placebo arm derived no benefit, they were transferred to the highest dose arm of 180mg.

Source: Medical Xpress

Journal information: Christopher D Buckley et al, Efficacy, patient-reported outcomes, and safety of the anti-granulocyte macrophage colony-stimulating factor antibody otilimab (GSK3196165) in patients with rheumatoid arthritis: a randomised, phase 2b, dose-ranging study, The Lancet Rheumatology (2020). DOI: 10.1016/S2665-9913(20)30229-0

Anaesthetic Clues Hidden in Tarantula Venom

In a finding that promises new research into pain management, a tarantula toxin molecule has been revealed to use a “stinger” to permanently close the voltage sensors on nerve cells’ sodium channels.

Chronic pain is difficult to treat, and attempts to seek relief can sometimes lead to opiate overdose, addiction, prolonged withdrawal, and even death. This means that there is a critical need to develop pain management medications that are safer, more effective and non-addictive. Tarantula toxin is of interest because it has to be fast-acting, shutting down the nerves of the tarantula’s prey and immobilising it before it can escape.

The tarantula toxin’s mechanism of action has proved elusive: the tarantula toxin-ion channel chemical complex has been hard to capture in its functional form. This has made it especially challenging to replicate the calcium-channel blocking effect in a small molecular form suitable for anaesthetic compounds. To overcome this obstacle, the researchers took a toxin-binding region from a specific type of human sodium channel that is key to pain transmission and imported it into their bacterium-derived model ancestral sodium channel. In doing so, they successfully obtained a clear molecular view of the configuration of the potent toxin from tarantula venom as it tightly binds to the sodium channel receptor site.

Prof William Catterall of the University of Washington School of Medicine explains: “Remarkably, the toxin plunges a ‘stinger’ lysine residue into a cluster of negative charges in the voltage sensor to lock it in place and prevent its function. Related toxins from a wide range of spiders and other arthropod species use this molecular mechanism to immobilise and kill their prey.”

The researchers hope that these insights will lead to the development of a new variety of anaesthetic compounds.

Source: News-Medical.Net