Levetiracetam pharmacokinetics in Japanese subjects with renal impairment

Development of a physiologically based pharmacokinetic model for levetiracetam in patients with renal impairment to guide dose adjustment based on steady-state peak/trough concentrations

Levetiracetam may cause acute renal failure and myoclonic encephalopathy at high plasma levels, particularly in patients with renal impairment. The aim of this study was to develop a physiologically based pharmacokinetic (PBPK) model to predict levetiracetam pharmacokinetics in Chinese adults with epilepsy and renal impairment and define appropriate levetiracetam dosing regimen.PBPK models for healthy subjects and epilepsy patients with renal impairment were developed, validated, and adapted. Furthermore, we predicted the steady-state trough and peak concentrations of levetiracetam in patients with renal impairment using the final PBPK model, thereby recommending appropriate levetiracetam dosing regimens for different renal function stages. The predicted maximum plasma concentration (Cmax), time to maximum concentration (Tmax), area under the plasma concentration-time curve (AUC) were in agreement (0.8 ≤ fold error ≤ 1.2) with the observed, and the fold error of the trough concentrations in end-stage renal disease (ESRD) was 0.77 - 1.22. The prediction simulations indicated that the recommended doses of 1000, 750, 500, and 500 mg twice daily for epilepsy patients with mild, moderate, severe renal impairment, and ESRD, respectively, were sufficient to achieve the target plasma concentration of levetiracetam.

Physiologically based pharmacokinetic modeling of levetiracetam to predict the exposure in hepatic and renal impairment and elderly populations

Levetiracetam (LEV) is an anti-epileptic drug approved for use in various populations. The pharmacokinetic (PK) behavior of LEV may be altered in the elderly and patients with renal and hepatic impairment. Thus, dosage adjustment is required. This study was conducted to investigate how the physiologically-based PK (PBPK) model describes the PKs of LEV in adult and elderly populations, as well as to predict the PKs of LEV in patients with renal and hepatic impairment in both populations. The whole-body PBPK models were developed using the reported physicochemical properties of LEV and clinical data. The models were validated using data from clinical studies with different dose ranges and different routes and intervals of administration. The fit performance of the models was assessed by comparing predicted and observed blood concentration data and PK parameters. It is recommended that the doses be reduced to ~70%, 60%, and 45% of the adult dose for the mild, moderate, and severe renal impairment populations and ~95%, 80%, and 57% of the adult dose for the Child Pugh-A (CP-A), Child Pugh-B (CP-B), and Child Pugh-C (CP-C) hepatic impairment populations, respectively. No dose adjustment is required for the healthy elderly population, but dose reduction is required for the elderly with organ dysfunction accordingly, on a scale similar to that of adults. A PBPK model of LEV was successfully developed to optimize dosing regimens for special populations.

Therapeutic drug monitoring and the therapeutic reference range of levetiracetam for Chinese patients: Problems and issues

BACKGROUND

Levetiracetam (LEV) is widely used in the clinical monotherapy or multi-drug combination treatment of seizures due to its good tolerability and efficacy. Due to a lack of large-scale clinical studies, the relationship between levetiracetam concentrations, disease activity and adverse is unclear, limiting the usefulness of therapeutic drug monitoring (TDM) based LEV plasma levels. This study was intended to investigate factors influencing the pharmacokinetics of and the appropriate reference range of LEV concentration using available LEV TDM data.

METHODS

A rapid, accurate and sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS) method was established to determine LEV plasma concentrations. In this study, the levetiracetam plasma concentration monitoring data from 352 samples (taken from 248 patients) were used to explore the relationship between levetiracetam dose, age, combined administration with other antiseizure medications in patients with epilepsy.

RESULTS

Age and combined administration emerged as important affecting factors for the correlation of LEV concentration and dose. The correlation between concentration and dose was better in monotherapy. Combined administration may affect LEV concentration, especially when LEV is combined with oxcarbazepine, which might decrease the LEV concentration.

CONCLUSION

These findings emphasize the need to monitor LEV routinely LEV, especially among children and older adults when other antiseizure comedications are prescribed in the treatment regimen. LEV TDM is a well-established tool for the management of patients with epilepsy.

Quantification of levetiracetam in plasma and urine and its application to a pharmacokinetic study of traumatic brain injury patients

Background: Levetiracetam is an antiepileptic drug used to prevent or treat seizure in patients with severe traumatic brain injury. This study aimed to develop and validate methodology suitable for measuring levetiracetam concentrations in human plasma and urine. Methods: Plasma or urine (10 μl) samples were spiked with [²H₆]-levetiracetam and processed using an acetonitrile precipitation. ESI-LC-MS/MS was employed for analyte detection. Results: The levetiracetam calibration was linear from 0.1 to 50 mg/l in a combined matrix of plasma and urine. Intra- and inter-assay imprecision and accuracy in plasma were <7.7 and 109%, and in urine were <7.9 and 108%, respectively. Conclusion: The validated method was applied to a pharmacokinetic study of levetiracetam in critically ill patients with severe traumatic brain injury.

Acute Kidney Injury Caused by Levetiracetam in a Patient With Status Epilepticus

Levetiracetam is a widely used, effective and usually well-tolerated anti-epileptic medicine. It is mostly excreted by kidneys and requires dose adjustment according to the glomerular filtration rate. Very few case reports have been published in the literature about levetiracetam causing acute kidney injury (AKI). We present a case of a 26-year-old male with a seizure disorder on levetiracetam, presented with status epilepticus requiring intubation for airway protection. He received 4 g of intravenous levetiracetam as a loading dose and continued with a maintenance dose of 750 mg intravenous every 12 hours. He had signs of AKI on day two and creatinine eventually reached a maximum level of 12.2 mg/dL. His kidney function improved to his new baseline in a period of 30 days without requiring renal replacement therapy. He did not have significant rhabdomyolysis and his kidney function started improving right after his anti-epileptic therapy was switched to valproic acid pointing towards levetiracetam as the primary cause of kidney injury. Clinicians should be aware that levetiracetam can cause AKI on patients with a seizure disorder, especially when administered in high doses. Kidney function should be monitored closely and patients should be treated aggressively with intravenous fluids when they have any signs of rhabdomyolysis to prevent further kidney damage.

Levetiracetam Pharmacokinetics in a Critically Ill Anephric Patient on Intermittent Hemodialysis

BACKGROUND

In patients requiring hemodialysis, the extracorporeal circuit is expected to remove the majority of serum levetiracetam. The preferred levetiracetam dosing regimen in critically ill patients exhibiting complex pharmacokinetic profiles undergoing hemodialysis is unknown. The objective of this case is to describe levetiracetam pharmacokinetics in a critically ill anephric patient receiving intermittent hemodialysis.

METHODS

This is a case report of a single patient.

RESULTS

A 43-year-old anephric female was admitted to the intensive care unit for concerns of new onset seizure activity. She was loaded with 2000 mg levetiracetam followed by a 750 mg daily maintenance dose. The levetiracetam volume of distribution was 0.48 L/kg, and the interdialytic elimination half-life was 31 h. Hemodialysis removed nearly 85% of serum levetiracetam, and the patient exhibited slightly higher than expected non-renal elimination. Pharmacokinetic simulations identified 500 mg daily with 750 mg post-dialysis supplements as the regimen most likely to reduce variability in serum levetiracetam concentrations and achieve levels in the therapeutic range.

CONCLUSION

Substantial elimination of levetiracetam by hemodialysis occurred in this case, and non-renal clearance was slightly higher than in previous reports. Insufficient intradialytic or post-dialysis levetiracetam concentrations may place patients at risk of breakthrough seizures. This case indicates that dialysis patients on levetiracetam may require higher post-dialysis supplemental doses than currently recommended and tailored therapy supported by therapeutic drug monitoring.

Population-Based Study of Risk of AKI with Levetiracetam

BACKGROUND AND OBJECTIVES

Regulatory agencies warn about the risk of AKI with levetiracetam use on the basis of information from case reports. We conducted this study to determine whether new levetiracetam use versus nonuse is associated with a higher risk of AKI.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a population-based retrospective cohort study of adults with epilepsy in Ontario, Canada. Patients who received a new outpatient prescription for levetiracetam between January 1, 2004 and March 1, 2017 were matched to two nonusers on stage of CKD, recorded seizure in the prior 90 days, and logit of a propensity score for levetiracetam use. The primary outcome was a hospital encounter (emergency department visit or hospitalization) with AKI within 30 days of cohort entry. Secondary outcomes were AKI within 180 days and change in the concentration of serum creatinine. We assessed the primary outcome using health care diagnosis codes. We evaluated the change in the concentration of serum creatinine in a subpopulation with laboratory measurements.

RESULTS

We matched 3980 levetiracetam users to 7960 nonusers (mean age 55 years, 51% women). Levetiracetam use was not significantly associated with a higher risk of AKI within 30 days (13 [0.33%] events in levetiracetam users and 21 [0.26%] events in nonusers [odds ratio, 1.24; 95% confidence interval, 0.62 to 2.47]). Similarly, there was no significant association with AKI within 180 days (odds ratio, 0.70; 95% confidence interval, 0.43 to 1.13). The change in the concentration of serum creatinine did not significantly differ between levetiracetam users and nonusers.

CONCLUSIONS

In this population-based study levetiracetam use was not associated with a higher risk of AKI.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_12_11_Yau_Podcast.mp3.

Clinical outcomes of intravenous levetiracetam treatment in patients with renal impairment

Intravenous levetiracetam has been approved for use as an antiepileptic drug, as well as in cases of status epilepticus. There are few reports that detail the clinical data and outcomes associated with this antiepileptic drug, particularly in patients with renal impairment. This was a retrospective analytical study conducted at Khon Kaen University's Srinagarind Hospital in Thailand. The study period was between January 1, 2010 and December 31, 2014. The inclusion criteria were that patents were over 15 years old, had renal impairment, and had received intravenous levetiracetam treatment. The main clinical outcomes were seizure control and mortality. Clinical outcomes were compared between those with and without status epilepticus. Mortality of patients with status epilepticus were compared in terms of seizure control and order of intravenous levetiracetam treatment. During the study period, there were 247 patients who met the study criteria. The average age of the patients was 58 years with nearly equal sex distribution. Of those, 90 patients (36.4%) had GRFs of less than 15 mL/min/1.73 m² and 60 patients (24.3%) received intravenous LEVE due to status epilepticus. The seizure control rates in the status epilepticus and non-status epilepticus groups were 36.7% and 88.7%, respectively (P<0.001). The mortality rate did not differ significantly between the two groups (33.3% vs 27.8%; P=0.418). There was no significant overall difference in mortality rate between seizure-controlled and seizure-uncontrolled patients in the status epilepticus group. In the convulsive status epilepticus group, variations in terms of treatment order of intravenous levetiracetam and seizure control resulted in no significant difference in mortality rates (P=0.311). No major side effects were detected in any patients after the intravenous levetiracetam treatment. In conclusion, intravenous levetiracetam treatment was effective and safe in patients with renal impairment.

Population Pharmacokinetic Modeling of Levetiracetam in Pediatric and Adult Patients With Epilepsy by Using Routinely Monitored Data

BACKGROUND

Levetiracetam, a second-generation antiepileptic drug, is frequently used for managing partial-onset seizures. About 70% of the administered dose is excreted in urine unchanged, and dosage adjustment is recommended based on the individual's renal function. In this study, a population pharmacokinetic model of levetiracetam was developed using routinely monitored serum concentration data for individualized levetiracetam therapy.

METHODS

Patients whose serum concentrations of levetiracetam at steady-state were routinely monitored at Kyoto University Hospital from April 2012 to March 2013 were enrolled. The influence of patient characteristics on levetiracetam pharmacokinetics was evaluated using the nonlinear mixed-effects modeling (NONMEM) program.

RESULTS

A total of 583 steady-state concentrations from 225 patients were used for the analysis. The median patient age and estimated glomerular filtration rate (eGFR) were 38 (range: 1-89) years and 98 (15-189) mL·min·1.73 m, respectively. Serum concentration-time data of levetiracetam were well described by a 1-compartment model with first-order absorption. Oral clearance was allometrically related to the individual body weight and eGFR. An increase in the dose significantly increased oral clearance. No improvement in model fit was observed by including the covariate of any concomitant antiepileptic drugs. The population mean clearance for an adult weighing 70 kg and with a normal renal function was 4.8 and 5.9 L/h for 500 mg bis in die (bid) and 1500 mg bid, respectively.

CONCLUSIONS

Oral clearance allometrically related with body weight and eGFR can well predict the routine therapeutic drug monitoring data from pediatric to aged patients with varying renal function. Dosage adjustments based on renal function are effective in controlling the trough and peak concentrations in similar ranges.

Does Secretory Clearance Follow Glomerular Filtration Rate in Chronic Kidney Diseases? Reconsidering the Intact Nephron Hypothesis

Drug‐dose modification in chronic kidney disease (CKD) utilizes glomerular filtration rate (GFR) with the implicit assumption that multiple renal excretory processes decline in parallel as CKD progresses. We compiled published pharmacokinetic data to evaluate if GFR predicts renal clearance changes as a function of CKD severity. For each drug, we calculated ratio of renal clearance to filtration clearance (Rnf). Of 21 drugs with Rnf >0.74 in subjects with GFR >90 mL/min (implying filtration and secretion), 13 displayed significant change in Rnf vs. GFR (slope of linear regression statistically different from zero), which indicates failure of GFR to predict changes in secretory clearance. The dependence was positive (n = 3; group A) or negative (n = 10; group B). Eight drugs showed no correlation (group C). Investigated drugs were small molecules, mostly hydrophilic, and ionizable, with some characterized as renal transporter substrates. In conclusion, dosing adjustments in CKD require refinement; in addition to GFR, biomarkers of tubular function are needed for secreted drugs.

Comparison of Levetiracetam Dosing Regimens in End-Stage Renal Disease Patients Undergoing Intermittent Hemodialysis

BACKGROUND

Levetiracetam (LEV) is primarily renally eliminated. In end-stage renal disease (ESRD) patients on hemodialysis (HD), pharmacokinetic studies recommend daily dosing with 50% supplemental doses after 4-hour HD sessions. However, poor medication adherence after HD could result in fluctuating plasma drug levels.

OBJECTIVE

To compare two LEV dosing regimens, daily versus twice-daily (BID), in ESRD patients undergoing HD.

METHODS

Consecutive ESRD patients (April 2013 to May 2014) receiving maintenance inpatient HD and prescribed LEV prior to admission to our academic tertiary hospital were prospectively analyzed. Demographics, initial lab values, adverse reactions, seizures, and LEV regimens were recorded. LEV levels were obtained pre-HD and post-HD along with levels after receiving post-HD doses. Recovery of plasma levels after HD was assessed by comparison of levels predialysis versus postdialysis and post-HD doses.

RESULTS

We identified 22 patients who met inclusion criteria; 14 BID and 8 daily dosing. Mean predialysis, postdialysis, and post-HD dose plasma levels were higher in patients receiving LEV BID compared with daily (43.1 ± 6.3, 19.4 ± 5.2, 34.9 ± 4.3 vs 21.1 ± 3.9, 6.9 ± 1.5, 11.9 ± 1.7 µg/mL; P < 0.05). BID post-HD levels were 41.9 ± 4.6% of predialysis levels versus 36.9 ± 7.3% with daily dosing ( P = 0.275). Post-HD dose levels were 81.4±4.3% of predialysis on LEV BID versus 65.7 ± 8.8% on LEV daily ( P = 0.045). No seizures were reported during hospital admission in either group.

CONCLUSIONS

Compared to LEV daily, BID dosing achieved significantly higher levels and a better recovery to predialysis levels. Although limited by small numbers, a similar relationship between postdialysis levels was not detected.

Haemodialysis significantly reduces serum levetiracetam levels inducing epileptic seizures: Case report

WHAT IS KNOWN AND OBJECTIVE

Levetiracetam is used in the treatment of some forms of epilepsy. In renal impairment and patients on chronic haemodialysis, dose adjustment is required. We report a case.

CASE DESCRIPTION

This case report describes a woman on levetiracetam treatment who presented with generalized tonic-clonic seizures during a haemodialysis session. We report on treatment adjustment and on the impact of dialysis on levetiracetam levels.

WHAT IS NEW AND CONCLUSION

Haemodialysis reduces serum levetiracetam concentration and can lead to subtherapeutic levels. Close monitoring is necessary when dialysis is used on patients receiving anticonvulsant drugs that are extensively eliminated by the procedure.