Cyclobenzaprine

Pain and inflammation

Also known as Flexeril

Cyclobenzaprine is a muscle relaxant for painful muscle spasms, usually after a strain or injury. It works on your nervous system rather than the muscle itself, which is why it makes most people genuinely sleepy. It's meant for short-term use — a few weeks — alongside rest and gentle movement. Treat the drowsiness with respect: no driving until you know how it hits you.

How to take it

When

As prescribed, often in the evening since it causes drowsiness. Short-term use only.

Food

With or without food — either is fine.

Avoid

No alcohol, and no driving or operating machinery until you know how sleepy it makes you. Not within 2 weeks of taking an MAOI antidepressant.

Good to know

Older adults are more prone to confusion, grogginess, and falls on this medicine — mention any of that to your doctor right away.

Missed a dose?

Take it when you remember, unless it's almost time for your next dose — then skip the missed one. Never double up.

Common side effects

Strong drowsiness
Dry mouth
Dizziness
Blurred vision
Constipation

Call a doctor if

Chest pain, pounding or irregular heartbeat, or fainting — call emergency services.
Fever with confusion, muscle stiffness, or twitching — could be serotonin syndrome, especially with antidepressants. Get help now.
Swelling of the face or throat, or trouble breathing — call emergency services.
New confusion or hallucinations, especially in an older adult — call the doctor right away.
Trouble urinating that's getting worse — call your doctor.

Educational only. This summary is drawn from public FDA labeling and MedlinePlus and simplified for readability. Your prescription label and your pharmacist always come first — doses and instructions vary from person to person.