What is the best course of action for a patient with a history of seizures on Keppra (levetiracetam) presenting with pinpoint pupils?

Management of a Patient with History of Seizures on Keppra Presenting with Pinpoint Pupils

In a patient with a history of seizures on Keppra (levetiracetam) presenting with pinpoint pupils, the most appropriate course of action is to evaluate for opioid toxicity as the likely cause of pinpoint pupils while maintaining seizure control with the current antiepileptic medication.

Initial Assessment and Management

Evaluate for Opioid Toxicity

• Pinpoint pupils (miosis) is a classic sign of opioid toxicity, not a side effect of levetiracetam
• Assess for other signs of opioid toxicity:
  • Respiratory depression
  • Decreased level of consciousness
  • Hypotension
  • Bradycardia

Immediate Interventions

1. If opioid overdose is suspected:

   • Administer naloxone (opioid antagonist)
   • Support airway, breathing, and circulation
   • Monitor vital signs closely

2. Continue levetiracetam therapy:

   • Do not discontinue Keppra as this could precipitate seizures 1
   • Maintain current dosing unless there are specific contraindications

Seizure Management Considerations

Levetiracetam (Keppra) Effectiveness

• Levetiracetam is an effective antiepileptic medication with a favorable safety profile 2, 3
• It has minimal drug interactions, making it suitable for patients with comorbidities 3
• Efficacy rates for seizure reduction range from 44-73% in various studies 4

Monitoring for Seizure Activity

• Assess for any clinical signs of seizure activity
• If patient has impaired consciousness that cannot be fully explained by opioid effect:
  • Consider continuous EEG monitoring for at least 24 hours to detect non-convulsive status epilepticus 1, 4
  • Non-convulsive status epilepticus can only be definitively diagnosed with EEG 4

Seizure Management in Special Circumstances

• If seizures occur despite levetiracetam therapy:
  • Consider adding a benzodiazepine as first-line treatment 4
  • For refractory seizures, additional options include valproate (88% success rate), additional levetiracetam (44-73% success rate), or phenytoin (56% success rate) 1, 4

Additional Diagnostic Considerations

Neuroimaging

• If this is a new presentation or there's a significant change in the patient's condition:
  • Consider brain CT scan to rule out acute intracranial processes, especially in elderly patients 4
  • Approximately 23% of new-onset seizures in elderly patients may have an underlying acute intracranial process 4

Laboratory Evaluation

• Complete toxicology screen to confirm opioid presence and identify other substances
• Basic metabolic panel to assess for electrolyte abnormalities that could lower seizure threshold
• Liver and kidney function tests to guide medication management

Follow-up Care

Seizure Control

• Regular follow-up every 3-6 months to assess seizure control and medication tolerability 4
• Monitor for cognitive effects of antiepileptic medications

Addressing Substance Use

• If opioid use is confirmed, develop a plan to address substance use disorder
• Consider referral to addiction medicine specialists
• Educate about risks of combining opioids with other medications

Key Pitfalls to Avoid

1. Do not discontinue levetiracetam abruptly - this can precipitate seizures, especially in a patient with known seizure disorder 1

2. Do not assume pinpoint pupils are caused by the seizure medication - levetiracetam does not typically cause miosis; look for other causes

3. Do not miss non-convulsive status epilepticus - in patients with altered mental status, EEG monitoring may be necessary to detect non-convulsive seizures 1, 4

4. Do not overlook potential drug interactions - while levetiracetam has fewer interactions than many antiepileptic drugs, concomitant medications should still be reviewed 3