SMA and muscle relaxants in the summer: What you need to know
Last updated July 16, 2025, by Mary Chapman
Fact-checked by Inês Martins, PhD
While muscle relaxants can be a valuable tool in managing the pain, discomfort, and spasms associated with spinal muscular atrophy (SMA), the combination of SMA and muscle relaxants in the summer may present unique challenges.
How muscle relaxants work in SMA
To move your muscles, the brain and spinal cord send signals through nerve cells called motor neurons. In SMA, these motor neurons gradually degenerate and die, so the signals can’t get through, causing your muscles to shrink and weaken from inactivity.
Some people with SMA also experience spasticity, or abnormal muscle tightness and muscle spasms, which can make movement harder and more uncomfortable. Muscle relaxants may be used to help ease these symptoms, helping improve comfort and mobility.
Why summer can increase risks
If you have SMA, staying cool and hydrated in the summer can sometimes be harder. Swallowing challenges or higher energy needs may affect how well your body handles heat.
On top of that, some muscle relaxants can make it harder to sweat or stay alert, which could further affect how your body deals with hot weather.
All of these factors can combine to make managing summer’s heat more challenging.
“Muscle relaxers should be used with caution,” says Natalie Katz, MD, PhD, codirector of the Duke Children’s Neuromuscular Program and an SMA researcher.
“Because these treatments work to reduce signaling in the nerves, there is the potential that your body may not respond as expected to environmental stimuli, particularly in response to heat,” Katz says. “This can lead to symptoms such as overheating more easily than normal, dehydration, and/or excessive fatigue.”
While the effects of such treatments typically wear off within a few hours, using them for several consecutive days or weeks can lead to a buildup of effects, she says.
Below are some key issues to watch for, as well as tips to help you stay safe and comfortable.
1. Dehydration
When you have reduced mobility, fatigue, or swallowing difficulties, all common symptoms of SMA, drinking enough fluids might feel harder, especially in the summer heat.
It’s important to closely monitor and manage your fluid intake, and ask your doctor if your medication should be changed or adjusted.
“Drinking water with electrolytes can aid in helping the body retain water,” Katz says.
2. Heat sensitivity and overheating
People with SMA may have a harder time handling heat, and muscle relaxants can sometimes make this worse by affecting how the body responds to temperature changes. [
Try to avoid too much heat exposure, keep yourself hydrated, and watch for signs like lightheadedness or muscle cramps. If your body isn’t sweating as it normally would, which can be a side effect of some muscle relaxants, this may also signal trouble regulating heat. If you notice anything worrisome, reach out to your doctor.
“If you experience increased sweating or feel warmer than normal, try to limit physical activity, stay in air-conditioned locations, and drink plenty of water to keep the core body temperature low,” Katz says.
3. Increased fatigue
Some muscle relaxants cause fatigue because they reduce the activity of nerve cells in the brain and spinal cord. This leads to a general sedative effect, which can add to the fatigue you might already be feeling from SMA. If you start feeling tired, it’s probably best to go to a cooler location and drink more fluids.
“Fatigue can be a side effect of the medication itself, but it can also be exacerbated if dehydrated,” Katz says. “When using muscle relaxers during the summer, try to limit use to only as long as necessary.”
4. Dizziness or drowsiness
By slowing down activity in the brain and spinal cord to reduce muscle spasms and tightness, some muscle relaxants can cause dizziness or drowsiness, which may be more noticeable or severe in the heat.
Because each treatment works through a unique mechanism, “specific concerns should be discussed directly with your doctor,” Katz says.
Make sure you stay hydrated and find ways to cool down, such as spending time in a shaded area. If you notice symptoms such as confusion, fainting, chest palpitations, or decreased urine output, reach out to your healthcare provider right away.
5. Muscle weakness
Some muscle relaxants may make your muscles feel even weaker, and when combined with heat, this may affect your balance and coordination and increase your risk of falling.
If you need extra support, consider using assistive devices — or bringing one with you just in case.
“Discuss with your doctor if there are alternative or additional options, such as physical therapy, that can be used to ease any muscle discomfort you may be experiencing,” Katz says.
Tips for staying summertime safe with muscle relaxants
If you take muscle relaxants, consider these tips for staying safe during the summertime:
- Stay well hydrated.
- Avoid the hottest parts of the day and seek air-conditioned or shaded environments.
- Talk to your doctor about any heat-related symptoms.
- Dress in lightweight, breathable clothing.
- Pace yourself with physical activity and rest as needed.
- Monitor for medication side effects and changes in how you feel.
Wherever summertime takes you, be sure to monitor your symptoms closely, drink plenty of fluids, and listen to your body to keep yourself safe and comfortable.
SMA News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
