What Is Tonmya, and Why Does It Matter?
Tonmya (cyclobenzaprine) is a non-opioid medicine approved by the FDA to treat fibromyalgia in adults. It’s taken once daily at bedtime as a small tablet that dissolves under your tongue. It provides faster pain relief by entering your bloodstream quickly and avoids the usual processing by the liver. This method may help reduce side effects caused by buildup of lingering byproducts in your body.
Fibromyalgia is a long-term condition in which your brain and nervous system become overly sensitive, causing your body to experience more pain than it normally should. Affecting about 10 million adults in the U.S., especially women, fibromyalgia causes widespread pain, poor sleep, tiredness, and stiffness in the morning. Many people with fibromyalgia say that poor sleep is one of the hardest symptoms to manage. Tonmya is different from other treatments because it focuses on improving sleep, which may help ease pain and fatigue over time.
Tonmya works by affecting certain brain receptors linked to sleep and pain, making it a new option for people who haven’t had success with other fibromyalgia treatments. Its active substance, cyclobenzaprine, was first approved by the FDA in 1977 as a muscle relaxant.
Why Was It Approved?
Tonmya was approved based on studies that showed that it was generally safe and effective in reducing pain, disturbed sleep, and fatigue in adults with fibromyalgia.
In two large studies that included nearly 1,000 adults with fibromyalgia, those who took Tonmya showed greater pain relief than those who took a placebo after 14 weeks of treatment.
Tonmya was generally well tolerated. The most common side effects reported in the studies were related to the mouth, such as numbness, tingling, discomfort, dryness, pain, canker sores, changes in taste, and drowsiness. These effects were usually mild, happened soon after taking the medicine, and went away quickly.
What Do I Need to Know?
Tonmya is taken once a day at bedtime after brushing your teeth and finishing other oral care activities. You start with one tablet under your tongue for the first two weeks and then increase to two tablets each night. Let the tablets fully dissolve under your tongue — don’t cut, crush, chew, or swallow them. To help prevent numbness or tingling in the mouth, take small sips of water before using Tonmya. Avoid eating or drinking for at least 15 minutes and talking for five minutes after taking the medicine.
If you miss a dose, do not take Tonmya during the day. Take it the next evening. Avoid driving or using heavy machinery until you are sure that Tonmya will not affect your ability to do so safely.
Tonmya is not safe for everyone. You should not take it if you have certain heart or liver problems, an overactive thyroid, or if you’re taking certain antidepressant medicines, opioid-based painkillers, or alcohol. Let your health care provider know if you have a history of difficulty in passing urine, an overactive bladder, certain eye problems like glaucoma, or are taking medicines for allergies.
Be sure to tell your health care provider about all medicines you take, including over-the-counter products and supplements, to avoid possible interactions. Taking Tonmya with medicines that affect the brain chemical serotonin can raise your risk for serotonin syndrome. This is a serious condition that can cause confusion, muscle stiffness, and stomach problems. If your health care provider decides you need to take Tonmya with one of these medicines, they will monitor you closely.
If you are pregnant or planning to become pregnant, you should avoid taking Tonmya. It may cause birth defects or miscarriage if taken around the time of conception or during early pregnancy. Use birth control during treatment and for two weeks after the last dose.
Because the studies did not include people over 65 or those with complex health or mental health conditions, talk to your health care provider to see if Tonmya is right for you. It is expected to be available in the U.S. by the end of 2025.