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Cyclobenzaprine

Flexeril, Amrix, Tonmya, Fexmid

Muscle relaxant • Centrally acting skeletal muscle relaxant

Premium

QT RiskSerotoninergicCNS Depressant

Half-life

18 hours

Protein Binding

93%

Metabolized By

CYP1A2, CYP3A4, CYP2D6

External

Drugs.com

Clinical alerts

QT prolongation

Avoid combining with other QT-prolonging agents; check electrolytes

Serotonergic

Serotonin syndrome risk when combined with other serotonergic drugs

Anticholinergic

Adds to anticholinergic burden, particularly in older patients

CNS depressant

Additive sedation with other CNS depressants and alcohol

Mechanism of action

Reduces muscle spasm through action at the brainstem; structurally related to TCAs

Recorded indications

From the drug index — may include conditions studied rather than approved indications

·Healthy Subjects (HS)
·High Tone Pelvic Floor Dysfunction
·Pharmakokinetic
·Open Label
·Phase 1

Interactions

No curated interaction pairs are recorded for Cyclobenzaprine. This is not a statement that none exist — check a full interaction reference before combining.

Common adverse effects

Drowsiness
Dry mouth
Dizziness
Fatigue
Constipation

Food, alcohol & herbal

Alcohol · major

Severe CNS depression

Pharmacokinetics

Half-life: 18 hours
Protein binding: 93%
Metabolised by: CYP1A2, CYP3A4, CYP2D6

Pregnancy & lactation

Not recorded for Cyclobenzaprine. Absence here means this database does not hold a category — not that the drug is safe in pregnancy or breastfeeding.

Sources

Assembled from: drug index, curated drug database.

Not a substitute for clinical judgement