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cyclobenzaprine (Rx)Brand and Other Names:Flexeril, Amrix, more...Fexmid

 
 
 

Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablet

  • 5mg
  • 7.5mg
  • 10mg

capsule, extended-release

  • 15mg
  • 30mg
more...

Muscle Spasm

Immediate-release tablet

  • 5 mg PO q8hr; may increase dose to 7.5-10 mg PO q8hr PRN

Extended-release capsule

  • 15 mg PO qDay; some patients may require up to 30 mg PO qDay

Geriatric Dosing

Muscle Spasm

  • Immediate-release tablet: 5 mg/day PO initially; titrate slowly upward and consider less frequent dosing
  • Extended-release capsule not recommended in elderly, because of increased plasma levels (40%) and prolonged half-life (56%) compared with young adults

Dosing Modifications

Hepatic impairment

  • Immediate-release tablet: 5 mg/day PO initially; titrate slowly and consider less frequent dosing
  • Extended-release capsule: Not recommended in mild-to-severe hepatic impairment

Renal Impairment

  • Not studied

Dosage Forms & Strengths

tablet

  • 5mg
  • 7.5mg
  • 10mg
more...

Muscle Spasm

Immediate-release tablet

  • <15 years: Safety and efficacy not established
  • >15 years: 5 mg PO q8hr; may increase dose to 7.5-10 mg PO q8hr PRN

Extended-release capsule

  • <18 years: Safety and efficacy not established
  • >18 years: 15 mg PO qDay; some patients may require up to 30 mg PO qDay
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Interactions

Interaction Checker

cyclobenzaprine and

No Results

     
     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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            Adverse Effects

            >10%

            Drowsiness (up to 39% immediate-release; 100% extended-release)

            Dry mouth (21-32%)

            Dizziness (3-11%)

            1-10%

            Pharyngitis (1-3%)

            Headache (1-5%)

            Fatigue (6%)

            Palpitations (6%)

            Bad taste in mouth (1-6%)

            Indigestion (4%)

            Blurred vision (3%)

            Constipation (1-3%)

            Asthenia (1-3%)

            Confusion (1-3%)

            Nausea (1-3%)

            Nervousness (1-3%)

            <1%

            Arrhythmia

            Hypotension

            Palpitation

            Syncope

            Tachycardia

            Vasodilation

            Cardiac dysrhythmia (rare)

            Cholestasis (rare)

            Hepatitis

            Jaundice

            Anaphylaxis (rare)

            Immune hypersensitivity reaction

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            Warnings

            Contraindications

            Hypersensitivity to drug or formulation components

            Hyperthyroidism

            During the acute recovery phase of myocardial infarction and in patients with arrhythmia, heart block or conduction disturbances, or congestive heart failure

            Concomitant use or within 14 days of discontinuing MAO inhibitors

            Hyperpyretic crisis seizures and deaths have occurred in patients receiving cyclobenzaprine (or structurally similar tricyclic antidepressants) concomitantly with MAO inhibitors

            Cautions

            Use only for short periods (2-3 wk)

            Use caution in urinary retention, narrow-angle glaucoma or IOP, or concomitant use of other anticholinergic drugs

            May cause drowsiness/dizziness; do not ingest alcohol or other CNS depressants; may impair ability to operate heavy machinery

            May take with food to avoid stomach upset

            Serotonin syndrome reported when coadministered with other drugs that increase serotonin (eg, SSRIs, SNRIs, TCAs, tramadol, bupropion, meperidine, verapamil, or MAO inhibitors [see also Contraindications])

            Not effective for treatment of spasticity associated with cerebral/spinal cord disease or for pediatric cerebral palsy

            Elderly patients may be more prone to adverse effects and require dose/frequency reduction

            Use immediate release with caution in hepatic impairment; extended-release form not recommended with hepatic impairment

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            Pregnancy & Lactation

            Pregnancy category: B

            Lactation: Excretion in milk unknown; use with caution

            Pregnancy Categories

            A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA:Information not available.

            more...
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            Pharmacology

            Mechanism of Action

            Relieves local skeletal muscle spasm; clinical response similar to diazepam

            Structurally related to cyclic antidepressants, and pharmacologic effects are similar, including reserpine antagonism, norepinephrine potentiation, potent peripheral and central anticholinergic effects, and sedation; reduces tonic somatic motor activity influencing alpha and gamma motor neurons

            Absorption

            Onset: 1 hr

            Duration: 12-24 hr

            Bioavailability: 33-55%

            Peak plasma time: 7-8 hr

            Peak plasma concentration: 15-25 ng/mL

            Distribution

            Protein bound: 93%

            Metabolism

            Hepatic via CYP3A4, 1A2, and 2D6; may undergo enterohepatic recirculation

            Elimination

            Half-life: 8-37 hours (immediate release); 32-33 hr (extended release)

            Excretion: Urine, feces

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            Images

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            Formulary

            FormularyPatient Discounts

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
            Add or Remove Plans
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            Select a box to add or remove a plan.

            Select a class to view formulary status for similar drugs

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