Cyclobenzaprine dosage, forms, and strengths

Cyclobenzaprine hydrochloride is a generic prescription skeletal muscle relaxant used to relieve painful muscle spasms due to musculoskeletal conditions. Cyclobenzaprine relieves muscle spasms and muscle pain by acting directly on the central nervous system (CNS), reducing muscle hyperactivity. Cyclobenzaprine is a tablet that can be taken up to three times a day for up to three weeks. It is also available as an oral extended-release capsules that only require a single daily dose.

RELATED: Learn more about cyclobenzaprine

Check our best Cyclobenzaprine prices

The dosages listed are general guidelines, especially around maximum dosage; your healthcare provider may adjust your dose based on individual health factors.

Cyclobenzaprine dosage for muscle spasms

For painful localized muscle spasms due to musculoskeletal conditions, cyclobenzaprine is part of a larger treatment regimen that also includes rest and physical therapy. The FDA has approved its use in adults and adolescents 15 years of age and older. It’s a short-term therapy, meant only to be used for short periods of two to three weeks.

Cyclobenzaprine dosage for fibromyalgia

Although cyclobenzaprine is only approved to provide relief of muscle spasms, healthcare providers sometimes prescribe it off-label to relieve sleep disturbances due to fibromyalgia. Dosing is typically done at bedtime to assist with sleep, but very large daily doses can be divided throughout the day. Because cyclobenzaprine is prescribed off-label for fibromyalgia, dosing and treatment duration have not been standardized. The maximum daily dosage for fibromyalgia is 40 mg per day according to some studies, but lower doses like 20 mg/day are preferable.

Personalized dosing considerations

Because cyclobenzaprine is broken down by the liver, people with impaired liver function may become more sedated when taking cyclobenzaprine than other patients. As a result, healthcare providers always start with the lowest dose of short-acting cyclobenzaprine, 5 mg daily in those with mild liver disease, and the medication is best avoided in patients with moderate to severe liver disease. The dose can be slowly increased if necessary while monitoring carefully. Extended-release cyclobenzaprine is avoided in elderly patients and in those with liver impairment.

No dose adjustment is indicated in those with altered kidney function, but caution is recommended due to lack of safety and efficacy data.

Cyclobenzaprine safety info

The most common side effects are drowsiness, dizziness, confusion, and dry mouth. Because of the risk for serious side effects, the FDA has approved cyclobenzaprine only for short-term use.

The use of cyclobenzaprine is contraindicated in people with:

• Known allergies to the drug

• Heart rhythm problems

• Heart block

• Heart failure

• Overactive thyroid

• Recently had a heart attack

Immediately stop using cyclobenzaprine and contact the prescriber or get medical attention if you experience symptoms of an allergic reaction or irregular heartbeat.

The most important safety concern is that cyclobenzaprine, as a CNS depressant, causes sedation, somnolence, dizziness, and confusion. Do not drive or engage in any other risky activities until you know how doses affect you. Do not drink alcohol on the days you take cyclobenzaprine.

Precautions are needed when cyclobenzaprine is used in people with: 

• A history of urinary retention

• Glaucoma

• High eye pressure

Cyclobenzaprine is not considered absolutely contraindicated in pregnancy, but its safety is not fully established. Use should be reserved for situations where benefits clearly outweigh risks, with preference for short-term, low-dose therapy, and close monitoring for adverse effects is recommended. 

Cyclobenzaprine is excreted into human milk in low concentrations, with a calculated relative infant dose (RID) of approximately 0.5% of the maternal weight-adjusted dose—well below the commonly accepted threshold of concern (10%) for most medications during lactation. However, cyclobenzaprine possesses sedative properties, and the medical literature recommends regular clinical assessment of the infant for signs of sedation, poor feeding, or other adverse effects if maternal use is necessary.

Cyclobenzaprine has several drug interactions that can cause serious complications. Make sure the prescriber knows about all medications being used before starting this drug. Here are the most important:

• Monoamine oxidase inhibitors (MAOIs)

MAO inhibitors are contraindicated for use with cyclobenzaprine. They cannot be used within 14 days before or after a cyclobenzaprine dose.

• Drugs that also cause sedation

Narcotic pain relievers, sedatives (benzodiazepines), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants, sleeping pills, barbiturates, and alcohol. Concomitant use of these drugs can worsen the sedative effects of cyclobenzaprine.

• Drugs that work like cyclobenzaprine, called serotonergic drugs

Taking more than one drug that raises serotonin levels can cause serotonin syndrome, a potentially severe condition caused by too much serotonin in the brain. These include antidepressants, other drugs that treat mental health issues, opioids, migraine medications, and others.

• Anticholinergic drugs

• Tramadol

• Verapamil

The health care provider is not required to gradually reduce the dose when it’s time to stop, but some people may experience adverse effects, including nausea, vomiting, sweating, and insomnia. To forestall these problems, some clinicians may choose to taper the dose at discontinuation, but there is no set tapering schedule.

How to take cyclobenzaprine

Cyclobenzaprine is taken by mouth as either a tablet or a capsule. Follow all the prescriber’s directions, and do not take more than the recommended dosage.

• This medicine is not for long-term use.

• Take this medicine at the same time each day.

• Doses can be taken with or without food.

  • If tablets or capsules cause stomach problems, try taking the dose with food.

• Tablets can be taken three times a day. 

  • Swallow the cyclobenzaprine oral tablet whole with a glass of water.

• Cyclobenzaprine extended-release capsules are taken once per day at the same time each day. 

• Swallow the oral extended-release capsule whole. Do not crush, break, or chew the capsules or granules inside the capsule.

• If you cannot swallow the capsule whole:

  • Open the capsule and sprinkle the contents over one tablespoon of applesauce. Do not use any food other than applesauce.

  • Swallow the mixture immediately without chewing. 

  • Rinse your mouth to ensure all of the medicine has been swallowed.

  • Do not save any of the mixture to use later.

• Cyclobenzaprine tablets or capsules should be stored at room temperature in a tightly closed container away from light and out of the reach of children.

Cyclobenzaprine dosage FAQs

What is the recommended starting dose of cyclobenzaprine for adults?

15 mg/day, either 5 mg cyclobenzaprine immediate release (IR) taken three times daily or 15 mg cyclobenzaprine extended release (ER) taken once daily.

How often can I take cyclobenzaprine in a 24-hour period?

Take only three doses of immediate-release cyclobenzaprine or one dose of extended-release cyclobenzaprine in a 24-hour period. 

Are there different dosage recommendations for elderly patients taking cyclobenzaprine?

Elderly patients are typically started on a lower dose because of the greater risk of side effects, but the maximum dosage can be the same as it is for younger adults. Although caution is recommended, clinicians should look at other medications to avoid drug interactions. Clinicians avoid prescribing extended-release cyclobenzaprine to older adults. 

Can the dosage of cyclobenzaprine be adjusted over time?

The doctor may change the initial cyclobenzaprine dose if the lower dose is inadequate for controlling pain. There are only two dosages for both immediate-release and extended-release cyclobenzaprine: 15 mg/day or 30 mg/day. Treatment only lasts two or three weeks.

What should I do if I miss a dose of cyclobenzaprine?

Take a dose as soon as you remember. If it is almost time for the next dose, wait until then and take that dose. Do not take extra medicine to make up for a missed dose.

Sources:

• Cyclobenzaprine, StatPearls

• Cyclobenzaprine capsule prescribing information, DailyMed (NIH National Library of Medicine)

• Cyclobenzaprine hydrochloride tablet prescribing information, DailyMed (NIH National Library of Medicine)

• Flexeril drug summary, Prescriber’s Digital Reference (PDR)

• Muscle relaxants (toxicity), Merck Veterinary Manual

• Symptoms of withdrawal from tricyclic antidepressants, Canadian Medical Association Journal