Laboratory and Monitoring Requirements for Levetiracetam and Quetiapine
Levetiracetam (Keppra) Monitoring
Routine laboratory monitoring is not required for levetiracetam. 1, 2
No Baseline Labs Needed
- Levetiracetam does not require baseline laboratory testing before initiation 1, 2
- No routine therapeutic drug monitoring (TDM) is necessary due to its linear pharmacokinetics, lack of drug interactions, and broad therapeutic window 1
When to Consider Serum Levels
Consider checking levetiracetam serum levels only in specific situations 1:
- Critically ill patients (clearance may be augmented, requiring higher doses) 1
- Pregnant patients (levels decline as pregnancy progresses due to increased GFR) 1
- Pediatric patients (clearance increased 30-40% compared to adults) 1
- Elderly patients >65 years (clearance decreased by almost half) 1
- Renal impairment (clearance declines linearly with creatinine clearance) 1, 3
- Suspected non-compliance when seizures are uncontrolled 1
Rare Hepatotoxicity Monitoring
- While extremely uncommon, asymptomatic liver enzyme elevation has been reported 4
- Consider checking liver enzymes if unexplained symptoms develop, but routine monitoring is not recommended 4
No Cardiac Monitoring Required
- ECG is not needed for levetiracetam administration 5
- Unlike phenytoin/fosphenytoin, levetiracetam does not prolong QT interval and requires no cardiac monitoring during loading or maintenance 6, 5
- Studies demonstrate no clinically relevant QTc changes even at supratherapeutic doses (5000 mg) 5
Quetiapine (Seroquel) Monitoring
Baseline ECG is recommended before initiating quetiapine.
Baseline ECG Requirement
- Obtain baseline ECG to assess QTc interval, as quetiapine can prolong cardiac repolarization 7
- Quetiapine is classified among antipsychotics associated with weight gain and metabolic effects 7
Follow-Up ECG Monitoring
- Repeat ECG if patient develops cardiac symptoms or if other QT-prolonging medications are added 7
- More frequent monitoring needed for patients with risk factors for QT prolongation (electrolyte abnormalities, cardiac disease, concomitant QT-prolonging drugs) 7
Additional Monitoring for Quetiapine
While not explicitly detailed in the seizure-focused guidelines provided, standard antipsychotic monitoring typically includes:
- Metabolic parameters (weight, glucose, lipids) given quetiapine's association with weight gain 7
- Electrolytes (potassium, magnesium) before ECG assessment 7
Summary Algorithm
For Levetiracetam:
- No baseline labs required 1, 2
- No routine ECG needed 6, 5
- Check serum levels only if: critically ill, pregnant, pediatric, elderly, renal impairment, or uncontrolled seizures despite therapy 1
For Quetiapine: