Would it be harmful to start a patient (pt) on anti-seizure medication if they don't have a seizure disorder?

Prophylactic Anti-Seizure Medication in Patients Without Seizures: Potential Harm and Lack of Benefit

Starting a patient on anti-seizure medication when they don't have seizures is not beneficial and may cause harm through unnecessary side effects, drug interactions, and negative impacts on quality of life. 1

Evidence Against Prophylactic Anti-Seizure Medication

The 2022 American Heart Association/American Stroke Association guidelines clearly state that prophylactic anti-seizure medication is not beneficial in patients without evidence of seizures 1. This recommendation is supported by multiple studies showing:

• No improvement in functional outcomes
• No improvement in long-term seizure control
• No reduction in mortality
• Potential cognitive impairment, particularly affecting specific domains 1

This recommendation carries a Class 3: No Benefit designation with Level B-NR evidence, indicating moderate-quality evidence from nonrandomized studies that consistently demonstrates lack of benefit 1.

Potential Harms of Unnecessary Anti-Seizure Medication

Starting anti-seizure medications in patients without seizures can lead to several adverse effects:

1. Neurological and psychiatric effects:

   • Cognitive impairment
   • Neuropsychiatric disorders
   • Fatigue 1

2. Systemic side effects:

   • Myelosuppression
   • Liver dysfunction
   • Dermatologic reactions 1
   • Headache, nausea, dizziness 2
   • Auditory and visual problems 2
   • Pancreatitis and kidney disorders in some cases 2

3. Drug interactions:

   • Enzyme-inducing anti-seizure drugs (phenytoin, phenobarbital, carbamazepine) can significantly affect the cytochrome P450 system
   • Altered metabolism of numerous medications including chemotherapeutic agents 1
   • Potential worsening of comorbid conditions like coronary and cerebrovascular disease 3

4. Paradoxical effects:

   • Some anti-seizure medications can actually induce seizures in certain patients 4
   • This paradoxical effect is particularly concerning in patients with certain epilepsy syndromes when the wrong medication is selected 4

Clinical Context and Guidelines

Multiple guidelines across different specialties consistently recommend against prophylactic anti-seizure medication:

• The 2022 AHA/ASA guidelines state prophylactic anti-seizure medication "is not beneficial to improve functional outcomes, long-term seizure control, or mortality" 1

• The National Comprehensive Cancer Network (NCCN) guidelines explicitly state that "the use of older, 'traditional' antiepileptic drugs as prophylaxis against seizures in patients who have never had a seizure or who are undergoing neurosurgical procedures is ineffective, and is not recommended" 1

• The Society for Neuro-Oncology (SNO) and European Association of Neuro-Oncology (EANO) guidelines indicate that prophylactic anti-seizure medications should not be used routinely in patients with newly diagnosed brain tumors 1

• The Society for Neuro-Oncology (SNO) consensus review states that "anti-seizure medications should not be used as primary prophylaxis among patients with brain metastases" 1

Special Considerations

Specific Clinical Scenarios

For patients with a first unprovoked seizure, the American College of Emergency Physicians guidelines suggest:

• No need to initiate anti-seizure medication for patients with a provoked seizure 1
• No need to initiate anti-seizure medication for patients with an unprovoked seizure without evidence of brain disease or injury 1
• Consideration of anti-seizure medication may be appropriate for patients with a first unprovoked seizure with a remote history of brain disease or injury 1

Risk Factors for Drug-Induced Seizures

Ironically, some medications can actually induce seizures, with risk factors including:

• History of epilepsy or seizures
• Cancer
• Blood-brain barrier dysfunction
• Concomitant neurological diseases
• Mental disorders
• Extremes of age (very young or elderly)
• Liver or kidney disease
• Polypharmacy 5

Conclusion

Starting anti-seizure medication in patients without seizures is not supported by evidence and may expose patients to unnecessary harm through adverse effects and drug interactions. The decision to initiate anti-seizure medication should be based on clear evidence of seizures or specific high-risk situations as outlined in clinical guidelines.