A New Treatment for Fibromyalgia?

Fibromyalgia can be characterized as widespread or multi-site pain that is present for at least three months and not attributed to another disease or condition.1 Many other non-pain symptoms are present in patients with fibromyalgia, including chronic fatigue, sleep disturbances, neurologic disturbances and disturbances of cognition and mood. Cognitive impairment can present as difficulty concentrating and forgetfulness, as well as disorganized thinking. Other symptoms can include musculoskeletal stiffness and environmental sensitivity, such as sensitivity to bright lights, loud noises, perfumes and cold.

The prevalence of fibromyalgia in the U.S. is estimated to be 2–6.4%, and the condition is more common in women than in men. On physical examination, there is an absence of focal changes, suggestive of arthritis or enthesitis, and widespread tenderness.

Patient Care

Fibromyalgia is managed with non-pharmacologic and pharmacologic therapies. Non-pharmacologic interventions include patient education about the disease and cognitive therapy, as well as increased activity and exercise routines. The most common medications prescribed for fibromyalgia, mostly off label, are tricyclic antidepressants, such as amitriptyline and related medications (e.g., cyclobenzaprine); serotonin-norepinephrine re-uptake inhibitors, such as duloxetine and milnacipran; and alpha-2 ligands, such as pregabalin and gabapentin.3

Only three medications have previously been approved by the U.S. Food & Drug Administration (FDA) to treat fibromyalgia:

reported treatment-emergent adverse events. The most commonly treatment-emergent adverse events were oral hypoesthesia (17.3% of patients treated with TNX-102 SL vs. 0.4% of patients treated with placebo), oral paresthesia (5.6% vs. 0.4%, respectively) and product taste abnormal (4.4% vs. 0.4%, respectively).

The study concluded that TNX-102 SL led to significant daily pain reductions with a good safety and tolerability profile.

Conclusion

Cyclobenzaprine hydrochloride in sublingual tablet form (TNX-102 SL; Tonmya) is the first medication to receive FDA approval for the treatment of patients with fibromyalgia in more than 15 years. Although it was well tolerated in clinical trials, these conditions are usually more ideal than in the real world.

Cyclobenzaprine has been around for more than four decades, so it is not a new pharmacologic agent, but rather a new dose and dosage form. Now that it is FDA approved, more widespread use of evening dosing of the agent, combined with real-world evidence, will demonstrate where it fits into the armamentarium for the management and care of patients with fibromyalgia.

Michele B. Kaufman, PharmD, BCGP, is a freelance medical writer based in New York City and a pharmacist at New York Presbyterian Lower Manhattan Hospital.

References

Goldenberg DL, Kaplan M. Fibromyalgia: Treatment in adults. In: Wallace DJ, Case SM, eds. UpToDate. Wolters Kluwer. 2025 Jul.

Lederman S, Arnold LM, Vaughn B, et al. Efficacy and safety of sublingual cyclobenzaprine for the treatment of fibromyalgia: Results from a randomized, double-blind, placebo-controlled trial. Arthritis Care Res (Hoboken). 2023 Nov;75(11):2359–2368.