ScienceNot yet confirmed elsewhere1 publisher2 min readPublished
Lacosamide, approved for epilepsy, slowed cartilage loss and eased pain in mouse models of osteoarthritis
Yale researchers report that the epilepsy drug lacosamide eased pain and slowed cartilage loss in mouse models and in human cartilage cells in the lab. The work is preclinical, and it still has to be tested in patients with osteoarthritis.
The Scientist · Science desk
What happened
- The team turned to lacosamide because it blocks sodium channels, and an earlier study by some of the same researchers linked the channel protein Nav1.7 to both pain signalling and cartilage turnover.
- Nav1.7 sits inside chondrocytes, the cells that balance removing old cartilage and laying down new, and in an osteoarthritic joint it is more active than it should be.
- In mice, injecting lacosamide directly into the affected joint worked better than giving it orally, even at lower doses.
- The catch was that the drug did not stay long once it was in the joint, so repeat injections were needed to keep it working.
Why it matters
- capability Protecting cartilage as well as easing pain would address a gap the report describes: current treatments manage pain, and replacement surgery is the only real fix.
- constraint The dose window limits delivery. Any formulation has to keep joint concentrations inside it for the whole dosing interval, so release rate becomes part of the efficacy question.
- decision Approved status should shorten the road to clinical tests, ScienceAlert says. In our view that holds most clearly for the drug itself, since the local-delivery results in mice used a gel formulation.
The results are published in Bioactive Materials [2]. ScienceAlert's account does not give the number of animals, the size of the pain or cartilage effects, the dose range, or how long the gel held the drug. The thing this doesn't tell you is how large "reduced" and "slowed" are. Cells in a dish cannot report pain, so the pain result has to rest on the mouse work [16].
On the dose, musculoskeletal biologist Chuan-Ju Liu said: "There is an optimal range where the drug helps restore balance without overcorrecting." [4] Liu added: "What stood out was not just its effectiveness, but how little of a dose was needed." [5] ScienceAlert reports that the researchers identified a "sweet spot" where the drug was most beneficial [3]. Liu's conclusion was: "This tells us the system is finely tuned." [15]
The gel follows from the leak. ScienceAlert describes joints as "leaky bucket" structures that quickly dissipate liquid treatments, and the injection tests packed lacosamide inside a gel to counter that [10]. Liu said: "It transforms a daily pill into a long-lasting, local treatment that stays active for a month or longer." [11] The month is Liu's description of the gel.
The mechanism is the team's hypothesis. Liu put it as a suggestion: "Our findings suggest that Nav1.7 is a dual-acting target." [13] ScienceAlert summarises the drug's action as turning down Nav1.7 activity [14]. The pain half has some outside support. Earlier research suggests lacosamide can work as a painkiller, though that work concerned a different Nav1.7-related condition [18].
What to watch
- Group sizes, effect sizes and the dose range in the full Bioactive Materials paper, against which the sweet spot can be judged.
- A measured release study showing whether the hydrogel holds lacosamide in the joint for the month Liu describes.
- A first trial of lacosamide in people with osteoarthritis, and whether it uses the gel injection or the oral drug.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence35
- Adoption
- Insufficient
- Hype gap+30
- Incentives
- Insufficient
- Confidence50
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
A team from the Yale School of Medicine found that the epilepsy drug lacosamide could be effective in osteoarthritis, easing pain and reversing some of the joint damage.
ReportedSupportedSource: ScienceAlert, reporting on the Yale School of Medicine teamView cited source - [2]
The lacosamide results are published in Bioactive Materials and show that in mouse models and human cartilage cells in the lab the drug encouraged cartilage repair, slowed its deterioration and reduced the associated pain.
- [3]
The researchers identified a 'sweet spot' dose at which the drug was most beneficial.
- [4]
"There is an optimal range where the drug helps restore balance without overcorrecting," said musculoskeletal biologist Chuan-Ju Liu.
ReportedSupportedSource: Chuan-Ju Liu, musculoskeletal biologist, quoted by ScienceAlertView cited source - [5]
"What stood out was not just its effectiveness, but how little of a dose was needed," Liu said.
- [6]
Lacosamide is a sodium channel blocker, and a previous study by some of the same researchers identified a sodium channel and protein called Nav1.7 as involved in both sending pain signals to the brain and regulating how cartilage is built up and broken down.
- [7]
Nav1.7 is active inside chondrocytes, the cells that manage the balance of removing old tissue and adding new tissue, and in a joint affected by osteoarthritis it is more active than it should be.
- [8]
In mice, injecting lacosamide directly into the affected joint worked better than giving it orally, even at lower doses.
- [9]
The drug did not stick around for long once injected into the joint, so repeat injections were needed to keep it working.
- [10]
In the injection tests, lacosamide was packed inside a gel to counteract the 'leaky bucket' nature of joints, which can quickly dissipate liquid treatments.
- [11]
"It transforms a daily pill into a long-lasting, local treatment that stays active for a month or longer," Liu said of the hydrogel.
- [12]
Current osteoarthritis treatments can manage the pain, but there is no real fix besides replacement surgery.
- [13]
"Our findings suggest that Nav1.7 is a dual-acting target," Liu said.
- [14]
ScienceAlert summarises lacosamide's action as dialing down the activity of Nav1.7.
- [15]
"This tells us the system is finely tuned," Liu said.
- [16]
The pain result has to rest on the mouse work, because isolated cartilage cells cannot report pain.
- [17]
Because lacosamide is already approved as an epilepsy drug, the time to clinical tests for osteoarthritis should be shorter.
- [18]
Past research suggests lacosamide can be effective as a painkiller, though the previous work concerned a different Nav1.7-related condition.
Sources
1 independent publisher whose own reporting we read for this story.
- sciencealert.comFDA-Approved Drug Could Be Repurposed to Relieve Osteoarthritis Pain And Protect Cartilage
1 article · October 13, 2026
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Topics
- OsteoarthritisFollow
- Hydrogel drug deliveryFollow
- Drug RepurposingFollow
Entities
- LacosamideFollow
- Yale School of MedicineFollow
- Chuan-Ju LiuFollow
- Nav1.7Follow
- Bioactive MaterialsFollow
- ScienceAlertFollow