Is syncope a side effect of Glatopa (glatiramer acetate)?

Syncope as a Side Effect of Glatiramer Acetate (Glatopa)

Yes, syncope is a documented side effect of glatiramer acetate (Glatopa), occurring in approximately 3% of patients treated with the medication compared to 2% in placebo groups. 1

Evidence for Syncope with Glatiramer Acetate

The FDA drug label for glatiramer acetate clearly documents syncope as an adverse reaction in clinical trials:

• In controlled clinical trials, syncope occurred in 3% of patients receiving glatiramer acetate compared to 2% of patients on placebo 1
• Syncope is categorized under "Nervous System Disorders" in the adverse reactions table 1
• It is listed among the more common neurological side effects, alongside tremor (4%), migraine (4%), and speech disorder (2%) 1

Mechanism and Clinical Presentation

While the exact mechanism of syncope with glatiramer acetate is not fully elucidated, it may be related to:

1. Immediate post-injection reaction - Glatiramer acetate can cause a post-injection systemic reaction characterized by flushing, chest tightness, palpitations, and dyspnea 2, which may lead to vasovagal syncope in susceptible individuals

2. Cardiovascular effects - The drug label notes infrequent cardiovascular adverse reactions including hypotension and postural hypotension 1, which can precipitate syncope

3. Possible immune-mediated reactions - Some patients develop antibodies to glatiramer acetate, though these typically don't interfere with clinical effects 2

Management of Syncope in Patients on Glatiramer Acetate

If a patient experiences syncope while on glatiramer acetate:

1. Evaluate the timing - Determine if syncope occurred in relation to injection (immediate post-injection reaction)

2. Assess for orthostatic hypotension:

   • Measure blood pressure in supine and standing positions
   • Consider fluid status and concomitant medications that may contribute to hypotension 3

3. Consider management options:

   • Ensure adequate hydration - fluid resuscitation via oral or intravenous bolus may be beneficial 3
   • Consider reducing or withdrawing other medications that may cause hypotension 3
   • For recurrent syncope, desensitization protocols have been successfully used for patients with systemic reactions to glatiramer acetate 4

Risk Factors and Prevention

Patients at higher risk for syncope with glatiramer acetate may include:

• Those with a history of vasovagal reactions
• Patients taking concomitant medications that lower blood pressure
• Individuals with dehydration or cardiovascular conditions

Preventive measures include:

• Administering the injection while seated or lying down
• Ensuring adequate hydration
• Monitoring for prodromal symptoms (lightheadedness, nausea, diaphoresis)
• Considering premedication in patients with previous reactions

Clinical Perspective

Despite the occurrence of syncope as a side effect, glatiramer acetate has an overall favorable safety profile with an "excellent risk-benefit ratio" for patients with relapsing-remitting multiple sclerosis 2. Most adverse effects are mild, with injection site reactions being the most common 5.

For patients who experience syncope or other systemic reactions but require continued treatment with glatiramer acetate, allergy workup including intradermal testing may help identify those with true hypersensitivity reactions 6, and desensitization protocols have been successfully implemented in some cases 4.