cyclobenzaprine

Absorption: Well absorbed from the GI tract following oral administration. Extent of absorption associated with SL administration unknown.

Distribution: Unknown.

Protein Binding: 93%.

Metabolism/Excretion: Primarily metabolized by the liver by CYP3A4 and CYP1A2, and to a lesser extent by CYP2D6. Metabolites primarily excreted by kidneys.

Half-Life: 1–3 days.

Time/Action Profile ⬆ ⬇

( skeletal muscle relaxation)

ROUTE	ONSET	PEAK‡	DURATION
PO	within 1 hr	3–8 hr	12–24 hr
PO-ER	unknown	unknown	24 hr
SL	unknown	4 hr	24 hr

‡Full effects may not occur for 1–2 wk.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Concurrent use of or use within 14 days of MAO inhibitor therapy;
Immediate period after MI;
Severe or symptomatic cardiovascular disease;
Cardiac conduction disturbances;
Hyperthyroidism.
Moderate or severe hepatic impairment (SL);
OB: Pregnancy (SL).

Use Cautiously in:

Cardiovascular disease;
Mild hepatic impairment (SL);
OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk (PO);
Lactation: Use while breastfeeding only if potential maternal benefit justifies potential risk to infant;
Rep: Women of reproductive potential (SL);
Pedi: Safety and effectiveness not established in children <18 yr (SL) or <15 yr (PO);
Geri: ↑risk of anticholinergic adverse reactions, sedation, and fractures in older adults. Avoid use in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

CV: arrhythmias

EENT: dry mouth, blurred vision

GI: oral hypoesthesia (SL), constipation, dry mouth (SL), dyspepsia, nausea, oral lesions (SL), oral pain (SL), oral paresthesia (SL), unpleasant taste

GU: urinary retention

Neuro: dizziness, drowsiness, confusion, fatigue, headache, nervousness

Interactions ⬆ ⬇

Drug-drug:

Avoid use within 14 days of MAO inhibitors (hyperpyretic crisis, seizures, and death may occur).
Additive CNS depression with other CNS depressants, including alcohol, antihistamines, opioid analgesics, and sedative/hypnotics.
Additive anticholinergic effects with drugs possessing anticholinergic properties, including antihistamines, antidepressants, atropine, disopyramide, haloperidol, and phenothiazines.
Drugs that affect serotonergic neurotransmitter systems, including tricyclic antidepressants, SSRIs, SNRIs, fentanyl, buspirone, tramadol, and triptans, may ↑ risk of serotonin syndrome.

Drug-Natural Products:

Kava-kava, valerian, chamomile, or hops can ↑ CNS depression.

Route/Dosage ⬆ ⬇

Acute Painful Musculoskeletal Conditions Associated with Muscle Spasm (Amrix and Fexmid)

PO (Adults and Children ≥15 yr): Immediate release: 10 mg 3 times daily (range 20–40 mg/day in 2–4 divided doses; not to exceed 60 mg/day). Extended release: 15–30 mg once daily.

Fibromyalgia (Tonmya)

Sublingual (Adults <65 yr): 2.8 mg once daily at bedtime for 14 days, then 5.6 mg once daily at bedtime thereafter.
Sublingual Geriatric Patients ): 2.8 mg once daily at bedtime.

Hepatic Impairment

Sublingual (Adults ): Mild hepatic impairment:2.8 mg once daily at bedtime.

Availability ⬆ ⬇

(Generic available)

Immediate-release tablets: 5 mg; 7.5 mg; 10 mg
Extended-release capsules (Amrix): 15 mg; 30 mg
Sublingual tablets: 2.8 mg

Assessment ⬆ ⬇

Assess pain, muscle stiffness, and range of motion before and periodically during therapy.
Assess for history of seizure, urinary retention, angle-closure glaucoma, and ↑ intraocular pressure prior to initiation, and atropine-like effects (dry mouth, blurred vision, ↑ ocular pressure, dizziness, tachycardia, tremor, fatigue) during therapy if initiated with a positive history of these conditions.
Geri: Assess older adults for anticholinergic effects .
Assess for serotonin syndrome (mental changes [agitation, hallucinations, coma], autonomic instability [tachycardia, labile BP, hyperthermia], neuromuscular aberrations [hyperreflexia, incoordination], GI symptoms [nausea, vomiting, diarrhea]), especially in patients taking other serotonergic drugs (SSRIs, SNRIs, triptans). If symptoms occur, discontinue cyclobenzaprine and any other serotonergic drugs immediately.

Lab Test Considerations:

Verify pregnancy status prior to initiation of SL tablets.

Implementation ⬆ ⬇

PO: Administer at same time daily. Administer with food to minimize gastric irritation. DNC: Swallow extended-release capsule or interior contents whole; do not crush or chew. Capsule may be opened and contents sprinkled onto applesauce; swallow immediately without chewing. Rinse mouth to ensure contents are swallowed.
Sublingual: Administer after brushing teeth and drinking a few sips of water to ensure a moist mouth. Place SL tablet under tongue until dissolved. DNC: Do not swallow whole, cut, crush, or chew. Avoid eating or drinking for ≥15 min after SL tablet has completely dissolved and avoid hot, cold, or acidic beverages until morning. Avoid talking for ≥5 min after administration.

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of medication. Advise patient to read Patient Information before starting therapy.
Instruct patient to take missed PO doses within 1 hr of scheduled time; otherwise, return to normal dose schedule. If a bedtime SL dose is missed, take the next evening. Do not take a missed dose during the day. Do not double doses. Do not stop abruptly.
Instruct patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care provider before taking any other Rx, OTC, or herbal products.
Advise patient to avoid concurrent use of alcohol or other CNS depressants.
May cause drowsiness, dizziness, and blurred vision. Caution patient to avoid driving or other activities requiring alertness until response to drug is known.
Advise patient if constipation occurs to ↑ fluid and fiber intake and notify health care provider if constipation persists.
Teach patient how to take SL tablets and advise that good oral hygiene, frequent mouth rinses, and sugarless gum or candy may help relieve dry mouth; notify health care provider if severe oral mucosal adverse reactions (local numbness, tingling, pain, inflammation, lesion) occur.
Advise patient to notify health care provider if signs of urinary retention (distended abdomen, feeling of fullness, overflow incontinence, ↓ urine output), or visual changes occur.
Instruct patient to notify health care provider immediately if signs/symptoms of serotonin syndrome, irregular or abnormal heartbeat, ↑ heartbeat, or allergic reaction (difficulty breathing, hives, swelling of face or tongue, itching) occur.
Rep: Advise women of reproductive potential to use effective contraception during and for 2 wk after therapy; notify health care provider if pregnancy is planned or suspected or if breastfeeding. Advise patients exposed to SL tablets during pregnancy to contact Tonix Medicines, Inc., 1-888-869-7633.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇