What to do with a patient with a levetiracetam (Keppra) level of 13.2 mcg/mL?

Management of Levetiracetam Level of 13.2 mcg/mL

The levetiracetam level of 13.2 mcg/mL is within the therapeutic range (12.0-46.0 mcg/mL) and does not require any dose adjustment or intervention.

Understanding Levetiracetam Therapeutic Levels

Levetiracetam (Keppra) is an antiepileptic medication commonly used for seizure management. The therapeutic range for levetiracetam is typically considered to be 12.0-46.0 mcg/mL, as indicated in the reference range provided.

Key points regarding this level:

• The current level of 13.2 mcg/mL falls within the lower portion of the therapeutic range
• This level is sufficient for seizure control in most patients
• Toxic levels for levetiracetam are not well established, as noted in the reference range information
• Levetiracetam has a wide therapeutic index and good safety profile 1

Clinical Interpretation

Efficacy Considerations

• A threshold concentration of 11 mcg/mL has been suggested for therapeutic response in patients with refractory epilepsy 2
• The current level of 13.2 mcg/mL exceeds this threshold
• In a study of status epilepticus, median plasma concentrations in responders were 19.5 mg/L, though there was no statistically significant difference between responders and non-responders 3

Safety Considerations

• Levetiracetam has minimal protein binding and a favorable safety profile 1
• At the current level, significant adverse effects are unlikely
• Common side effects at therapeutic levels may include:
  • Somnolence
  • Dizziness
  • Irritability
  • Fatigue

Management Algorithm

1. Continue current dosing regimen

   • The level is therapeutic and no adjustment is needed

2. Monitor for clinical response

   • If seizures are well-controlled, maintain current dosing
   • If breakthrough seizures occur despite this therapeutic level, consider:
     • Increasing dose to achieve higher concentration within therapeutic range
     • Adding or switching to another antiepileptic medication

3. Monitor for adverse effects

   • Routine monitoring for common side effects
   • No specific monitoring required for toxicity at this level

4. Consider special populations

   • In patients with renal impairment: dose adjustment may be needed as levetiracetam is primarily renally cleared 4
   • In elderly patients: clearance may be decreased by approximately 38% 4

Important Clinical Pearls

• Levetiracetam levels do not need to be routinely monitored in most patients due to its wide therapeutic window 1

• Level monitoring is most useful for:

  • Confirming medication adherence
  • Assessing for potential toxicity in patients with symptoms
  • Guiding dosing in patients with renal impairment

• Higher doses (>1000 mg total daily dose) may be more effective for seizure prophylaxis in neurocritical care patients 5

• Oral loading of levetiracetam is generally well-tolerated, with 89% of patients reporting no adverse effects in one study 6

In conclusion, the current levetiracetam level of 13.2 mcg/mL is therapeutic and requires no specific intervention or dose adjustment, assuming the patient is clinically stable without breakthrough seizures.