What Factors Affect a Sufficient Cyclobenzaprine Dose?

The muscle relaxant cyclobenzaprine is often used to treat conditions that can cause muscle spasms, and the pain that can result from them. Many conditions can cause these spasms, and depending on the condition and its severity, different doses of this medication may be used. Other factors can influence cyclobenzaprine dose levels, including tolerance to the medication, age of the patient, and the presence of liver damage.

Usually, this medication is available in an oral tablet form, so the dosages discussed all pertain to an oral route of administration. Adults that have muscle spasms usually begin taking 5 milligrams (mg) of this drug, up to three times a day. For more intense spasms, or if the patient has a tolerance to this medication, the cyclobenzaprine dose might be increased to 7.5 mg or 10 mg, taken three times daily. Extended release capsules, which administer a regular dose of this drug throughout the day, can also be used. Patients generally take one 15 mg or 30 mg extended release capsule once a day in these cases.

Older patients often use a lower cyclobenzaprine dose, and take dosages less frequently. Initial doses for older patients are 5 mg, taken twice a day. More severe muscle spasms can lead a doctor to prescribe doses of 7.5 mg or 10 mg, taken twice a day. Due to the risk of sedation and interactions with other medications, elderly patients usually are not prescribed the extended release capsules.

Patients with liver problems are often unable to metabolize, or break down, medications as rapidly as healthy patients. Some drugs are given in lower doses or less often in patients with liver damage for this reason. For this medication, doctors recommend a lower cyclobenzaprine dose, given less frequently, for patients with a liver condition.

Studies have been performed using a lower cyclobenzaprine dose to reduce sedation, which is a common side effect of this medication. These studies utilized dosages of 2.5 mg or 5 mg administered several times a day. It was found that these dosages caused less sedation than dosages of 10 mg, several times a day. For some patients, 2.5 mg cyclobenzaprine each day proved insufficient to substantially reduce muscle spasms, although 5 mg dosages were sufficient to control pain and spasms.

The United States Food and Drug Administration (FDA) has approved lower dosages of 2.5 to 5 mg of cyclobenzaprine to treat some forms of back pain. These doses are typically sufficient to control mild back pain, and allow individuals to avoid sedation. Studies that found the 2.5 mg dosages insufficient generally involved patients with more severe spasms, which may explain why 2.5 mg was not always a sufficient dose in those pieces of research.