Background and Importance Monitoring of levetiractetam is necessary for treatment optimisation due to their wide interindividual pharmacokinetic variability. Age,clinical situation and pregnancy contribute greatly to its pharmacokinetic alterations.

Aim and Objectives To evaluate the impact and usefulness in clinical practice of pharmacokinetic monitoring of levetiracetam in a tertiary university hospital carried out by the pharmacy service.

Material and Methods Retrospective observational study in 53 patients between 02/2016–05/2023. Pharmacokinetic and patient data were obtained from Gestlab® and Orion Clinic® software:sex,age,weight,concomitant antiepileptic,creatinine value and hepatic insufficiency diagnosis.Patients were classified:paediatric(0–14years),pregnant,critical ill or outpatients.The clinical relevance of levetiracetam monitoring was assessed by whether the first levetiracetam level of patients was within or outside the therapeutic range(12–46mcg/mL) and the pharmacokinetic recommendation made by the pharmacy service.

Fifty-three patients were studied 25 men and 28 women with a median of 4(4) years and 18(20)Kg in paediatric and of 42(32.25) years and 69(34)Kg in adults. There were 33% paediatric,6% pregnant,15% critical ill and 45% outpatients.Two patients had creatinine levels above 1.3mg/dL,two diagnosed with liver failure and 43% had concomitant antiepileptic treatment. 53% of patients had levetiracetam level out of range,79% were below:14% pregnant,41% paediatric,9% critical ill and 36% outpatient. 68% were adjusted according to the pharmacy service of which 100% decided to increase the dosage:100% of pregnant and critical,63% of outpatient and 55% of paediatric. In 32% not adjusted,29% got the treatment suspended,29% was increased by the physician and 14% was not possible to carry out the pharmacokinetic report. The remaining 21% were above the range:17% were critical ill and 83% outpatient,50% percent were adjusted according to the pharmacy service:60% of outpatient in which 100% decided to reduce the dosage. In 50% not adjusted,33% it was not possible to carry out the pharmacokinetic report. Treatment was adjusted in 2 patients despite they were within range due to poor renal function or by decision of the physician.

Conclusion and Relevance Monitoring of levetiracetam levels has been shown to be clinically relevant for better individualisation of treatment since more than half of the patients were out of range. This has allowed pharmacokinetic adjustment in most cases to maintain the drug in therapeutic range and optimise treatment,especially in pregnant,critical ill and paediatric patients.

Conflict of Interest No conflict of interest.