Why would I give Flexeril (cyclobenzaprine) to a pregnant woman with a headache?

You Should NOT Give Flexeril (Cyclobenzaprine) to a Pregnant Woman with a Headache

Flexeril (cyclobenzaprine) is a muscle relaxant indicated for musculoskeletal conditions, not headache, and has no established role in migraine or headache management during pregnancy. 1

Why Cyclobenzaprine is Inappropriate

Wrong Indication

• Cyclobenzaprine is FDA-approved specifically for muscle spasm associated with acute musculoskeletal conditions, not for headache treatment 1
• There is no evidence supporting its use for migraine or any primary headache disorder in pregnancy 2, 3, 4, 5

Pregnancy Safety Concerns

• While cyclobenzaprine is Pregnancy Category B (no evidence of harm in animal studies), there are no adequate and well-controlled studies in pregnant women 1
• The FDA label explicitly states it "should be used during pregnancy only if clearly needed" 1
• Cyclobenzaprine is structurally related to tricyclic antidepressants and carries similar concerns about CNS effects 1

Risk of Inappropriate Polypharmacy

• Cyclobenzaprine has significant drug interactions with serotonergic medications (SSRIs, SNRIs, TCAs) that may be used in pregnancy, risking serotonin syndrome 1
• It enhances effects of other CNS depressants, which could compound sedation risks 1

What You SHOULD Give Instead

First-Line Acute Treatment

• Acetaminophen 1000 mg is the first-line medication for acute headache treatment during pregnancy 2, 3, 4
• This is the safest option with the most extensive safety data across all trimesters 2

Second-Line Options (if acetaminophen fails)

• NSAIDs like ibuprofen can be used ONLY during the second trimester 2, 4
• Avoid NSAIDs in first and third trimesters due to specific risks (first trimester: potential miscarriage; third trimester: premature ductus arteriosus closure) 4

For Severe, Refractory Migraine

• Sumatriptan may be used sporadically under specialist supervision when other treatments fail 2, 4
• Most safety data exists for sumatriptan specifically among the triptans 2

Adjunctive Therapy for Nausea

• Metoclopramide 10 mg is safe and effective for migraine-associated nausea, particularly in second and third trimesters 2, 6
• Prochlorperazine can also be used for both nausea and headache pain 6, 3

Critical Red Flags to Exclude First

Before treating any headache in pregnancy as benign, you must urgently evaluate for:

• New headache with hypertension should be considered preeclampsia until proven otherwise 2, 7
• This requires immediate blood pressure control and obstetric consultation, not simple analgesics 8, 7
• Other life-threatening causes include stroke, cerebral venous thrombosis, subarachnoid hemorrhage, and eclampsia 5

Common Pitfalls to Avoid

• Never use opioids or butalbital-containing medications for headache in pregnancy due to dependency risks, rebound headaches, and potential fetal harm 2, 6, 7
• Avoid ergotamine derivatives and dihydroergotamine throughout pregnancy due to oxytocic properties 2, 6
• Do not use topiramate, candesartan, or sodium valproate as these are contraindicated due to teratogenic effects 2

Non-Pharmacological Approaches Should Always Be First

• Maintain adequate hydration, ensure regular meals, secure consistent sleep patterns, and identify/avoid migraine triggers 2
• Consider biofeedback, relaxation techniques, massage, and ice packs before or alongside any medication 3, 9