What causes involuntary lower jaw movement in a patient on sertraline and how is it managed?

Involuntary Lower Jaw Movement in a Patient on Levodopa-Carbidopa and Sertraline

The involuntary lower jaw movement is most likely sertraline-induced extrapyramidal symptoms (EPS), specifically orofacial dyskinesia or dystonia, and should be managed by immediately discontinuing sertraline and administering anticholinergic medication (e.g., benztropine or diphenhydramine) for acute symptom relief. 1, 2

Cause: Sertraline-Induced Extrapyramidal Symptoms

Sertraline is the primary culprit in this clinical scenario, despite being marketed as a "safe" SSRI. The evidence clearly demonstrates:

• Sertraline causes extrapyramidal symptoms including facial spasms, dystonia, akathisia, and orofacial dyskinesias through serotonin-dopamine pathway interactions 1, 2
• A documented case of a 16-year-old on sertraline 200 mg/day developed facial spasm, upper limb dystonia, and akathisia that resolved after sertraline discontinuation and scopolamine administration 1
• Multiple published cases confirm sertraline-induced EPS, with quantitative documentation using the Abnormal Involuntary Movement Scale 2
• SSRIs like sertraline can cause myoclonus (level A evidence), which may manifest as jaw movements 3

Levodopa-carbidopa is less likely the cause because dyskinesias from dopaminergic therapy typically present as choreiform movements affecting multiple body regions, not isolated jaw movements in early treatment. However, it cannot be completely excluded.

Immediate Management Algorithm

Step 1: Discontinue Sertraline Immediately

• Stop sertraline without tapering if symptoms are acute and distressing 1
• Document baseline abnormal movements using the Abnormal Involuntary Movement Scale 4

Step 2: Administer Anticholinergic Medication

• Give benztropine 1-2 mg IM/IV or diphenhydramine 25-50 mg IM/IV for acute dystonic reactions 4
• Anticholinergic agents are effective for acute dystonia and Parkinsonian symptoms 4
• For persistent akathisia (if present), consider propranolol 10-20 mg TID or benzodiazepines, as antiparkinsonian agents are inconsistently helpful 4

Step 3: Monitor for Resolution

• Symptoms should significantly improve within 24-72 hours after sertraline discontinuation 1
• If symptoms persist beyond 1 week, consider tardive dyskinesia (though unlikely with short-term SSRI use) 4

Step 4: Switch Antidepressant if Needed

• Consider fluoxetine or citalopram as alternative SSRIs if depression treatment must continue 5
• Avoid paroxetine due to higher discontinuation syndrome risk and increased association with movement disorders 5
• Citalopram requires caution at doses >40 mg/day due to QT prolongation risk 5

Critical Pitfalls to Avoid

Do not misinterpret akathisia as psychotic agitation or anxiety - this is a common error leading to inappropriate dose escalation rather than reduction 4

Do not assume levodopa-carbidopa is the sole cause without first addressing sertraline, as SSRI-induced EPS is well-documented but frequently overlooked 1, 2

Do not continue sertraline at reduced doses - complete discontinuation is necessary for acute EPS, unlike tardive dyskinesia management where continuation might be considered 4, 1

Rule out serotonin syndrome - check for additional symptoms including hyperthermia, rigidity, autonomic instability, altered mental status, especially if other serotonergic agents are present 5, 6

Monitoring After Resolution

• Reassess every 3-6 months for any persistent movement abnormalities if antipsychotic or SSRI therapy is reintroduced 4
• Document that sertraline caused EPS in the medical record to prevent future re-challenge 1
• If depression requires ongoing treatment, select non-serotonergic alternatives (e.g., bupropion, mirtazapine) to avoid recurrence 4