Mirogabalin May Help Lessen Neuropathic Pain in Fibromyalgia, Rat Study Shows

Mirogabalin May Help Lessen Neuropathic Pain in Fibromyalgia, Rat Study Shows

Mirogabalin besylate, a calcium channel blocker approved as a treatment for neuropathic pain in Japan and marketed under the brand name Tarlige, reduced pain scores in two rat models of fibromyalgia, a study shows.

The study, “Analgesic effects of mirogabalin, a novel ligand for α2δ subunit of voltage-gated calcium channels, in experimental animal models of fibromyalgia,” was published in the journal Naunyn-Schmiedeberg’s Archives of Pharmacology.

Fibromyalgia is a chronic condition consisting of widespread pain and extreme sensitivity to mechanical stimulus-like pressure. Other symptoms including fatigue, sleep disturbances, and psychological disorders such as depression and anxiety are often linked to fibromyalgia.

Although the exact cause of fibromyalgia is unclear, scientists believe that pain is not processed correctly at the brain level, leading to excessive sensitivity and pain perception.

Neuropathic pain is the term used to describe the pain felt by a damaged nervous system. Due to its basis in neurological dysfunction, fibromyalgia can be studied in models that mimic pain caused by damage to the central or peripheral nervous system.

In this study, researchers used two different rat models of fibromyalgia — the intermittent cold stress model (ICS) and the unilateral intramuscular acidic saline injection model (Sluka model) — to evaluate mirogabalin’s potential to act as an analgesic for fibromyalgia.

Chemically, mirogabalin (developed by Daiichi Sankyo and marketed as Tarlige) is a gabapentinoid that works as a calcium channel blocker. Even though gabapentinoids were initially developed to treat seizures caused by epilepsy, they were shown to have anti-pain effects.

To further test the pharmacological characteristics of mirogabalin that could suit fibromyalgia treatment, researchers gave three doses of 1, 3, or 10 milligrams per kilogram of rat weight (mg/kg) to the two animal models.

They observed that the pain score in the ICS model after mechanical stimulus decreased proportionally to the mirogabalin dose. Moreover, Sluka model rats were able to sustain more pain four to six hours after treatment with mirogabalin than untreated rats.

The team also tested another gabapentinoid, Pfizer‘s Lyrica (pregabalin) currently used to treat fibromyagia. At a dose of 30 milligrams per kilogram, the medicine also improved the pain threshold sustained by the Sluka rat model, but a similar effect was obtained for mirogabalin at a lower dose of 3 mg/kg.

“The pharmacological profile of mirogabalin, potent and long-lasting analgesic effects with a wide safety margin, might be advantaged compared with the current standard of care for chronic pain,” the researchers wrote.

“Mirogabalin may have the potential to provide effective pain relief in patients with fibromyalgia,” the study concluded.