IMI-PAINCARE researchers’ evidence suggests the receptor could be targeted to increase the efficacy of pain drugs

Image by molotoka via Shutterstock
Image by molotoka via Shutterstock 


The burden of painful bladder and cystitis is huge, and it’s a problem that disproportionately affects women. Researchers from the IMI-PAINCARE project have found evidence that a receptor called σ1-R, or sigma-1, is present in the human urinary bladder. In a new report, they have documented the functional role of this receptor in cystitis by comparing responses in animal models, concluding that it could offer a potential new drug target for the treatment of diseases involving the urinary system.

They found that antagonists of this receptor – an antagonist is a substance that acts against and blocks an action – can improve the manifestations of cystitis. Namely, it modulates morphine analgesia against urological pain, meaning that by inhibiting the function of the receptor, the pain-killing effects of morphine and other opioid agonists can be enhanced without increasing their side effects. The paper concludes that this presents a potentially attractive new drug target for testing in human urinary bladder disorders for which there is currently no adequate treatment, and a sigma-1 antagonist called E-52862 is currently in Phase 2 studies in patients with neuropathic pain. The compound could be used together with morphine and would allow for lower morphine dosing, while at the same time decreasing inflammation, potentially enhancing recovery.


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Publication: Predictors of the placebo analgesia response in randomized controlled trials of chronic pain

Publication: Urinary bladder sigma-1 receptors: A new target for cystitis treatment