Therapeutic Drug Monitoring of Levetiracetam and Lamotrigine: Is There a Need?

Levetiracetam pharmacokinetics in venovenous extracorporeal membrane oxygenation: A case report

This case report describes the pharmacokinetics of levetiracetam in a critically ill patient supported on venovenous membrane oxygenation. While levetiracetam has emerged as a first line option to treat seizures in critically ill patients, there is limited information available regarding the impact of extracorporeal membrane oxygenation on the pharmacokinetics of this medication. This report contributes to the limited body of literature describing the pharmacokinetics of medications in extracorporeal membrane oxygenation.

A survey on the knowledge and attitudes of pharmacists towards the application of antimicrobial therapeutic drug monitoring and its challenges in Qatar

INTRODUCTION

Therapeutic drug monitoring (TDM) is an integral part of pharmaceutical care. Antimicrobials are amongst the most commonly monitored medications. Therefore, identifying the gaps in antimicrobial pharmacokinetics and TDM knowledge and skills among pharmacists is crucial to optimize TDM application.

RESEARCH QUESTION

What is the current knowledge, attitudes and perceived barriers of pharmacists in Qatar towards the application of antimicrobial TDM?

STUDY DESIGN

Cross-sectional survey.

METHODS

The psychometric validation of the survey underwent 3 stages: domain identification and item generation, content validation, and pilot test. The survey was divided into 4 domains (participant characteristics, knowledge, attitudes, and perceived barriers). It was developed in Survey Monkey and distributed to all pharmacists in Hamad Medical Corporation (HMC) hospitals via email. Data was analyzed using IBM Statistical Package for the Social Sciences (SPSS). Categorical and quantitative variables were expressed as frequencies with percentages and medians with interquartile ranges, respectively. Mann-Whitney U-test was used to test the effect of demographic and professional parameters on the knowledge scores. P values less than 0.05 were considered significant.

RESULTS

Forty-nine responses were collected. The median age of respondents was 34 years and 51% of them were males. Most respondents were clinical pharmacists (47%). On average, 44% of knowledge questions were correct, whereas 32% were incorrect and 23% were not sure of the answer. The median knowledge score was 5 out of 10 (interquartile range 2.5-6). Participants with post-graduate degrees or prior pharmacokinetic training showed trends towards higher knowledge scores. Online pharmacokinetics calculators were the most frequently used dose adjustment method. The top perceived barriers for the implementation of antimicrobial TDM were lack of knowledge and lack of educational sessions.

CONCLUSIONS

Albeit pharmacists in Qatar had modest level of knowledge about antimicrobial TDM, they had positive attitudes towards TDM and its implications in the clinical practice. Future plans should include providing TDM-related education activities.

Pharmacokinetics and Proposed Dosing of Levetiracetam in Children With Obesity

OBJECTIVE

Characterize levetiracetam pharmacokinetics (PK) in children with obesity to inform dosing.

METHODS

Children 2 to <21 years old receiving standard of care oral levetiracetam across two opportunistic studies provided blood samples. Levetiracetam plasma PK data were analyzed with a nonlinear mixed-effects modeling approach. Indirect measures for body size and covariates were tested for model inclusion. Individual empirical Bayesian estimates using the final model parameters were compared by obesity status. Monte Carlo simulation using total body weight was performed in children with normal estimated glomerular filtration rate to identify dosing for children with obesity that resulted in comparable exposures to normal weight adults and children after receiving label dosing.

RESULTS

The population PK model was developed from 341 plasma concentrations from 169 children. A 1-compartment model best fit the data with fat-free mass as a significant covariate. Compared with children with normal weight, children with obesity had significantly lower body weight-normalized clearance (median [range], 4.77 [1.49-10.44] and 3.71 [0.86-13.55] L/h/70 kg, respectively). After label dosing with the oral formulation in children with obesity 4 to <16 years old, maximum and minimum steady-state concentrations were higher (25% and 41%, respectively [oral solution] and 27% and 19%, respectively [tablet]) compared with children with normal weight. Comparable exposures between children with and without obesity were achieved with weight-tiered dosing regimens of <75 kg or ≥75 kg.

CONCLUSIONS

Weight-tiered dosing for levetiracetam oral solution and tablets for children with obesity 4 to <16 years old results in more comparable exposures to children of normal weight.

Therapeutic drug monitoring in India: A strength, weakness, opportunity and threats analysis

Over the last three to four decades, Therapeutic Drug Monitoring (TDM) has shaped itself as therapeutic drug management, an integral component of precision medicine. The practice of TDM is not extensive in India, despite being one of the fastest-growing economies in the world. It is currently limited to a few academic medical centres and teaching hospitals. Apart from the immunosuppressive drugs, several other therapeutic areas, such as anticancer, antifungal, antibiotic and antitubercular, have demonstrated great potential to improve patient outcomes in Indian settings. Factors such as the higher prevalence of nutritional deficiencies, tropical diseases, widespread use of alternative medicines, unalike pharmacogenomics and sparse population-specific data available on therapeutic ranges of several drugs make the population of this subcontinent unique regarding the relevance of TDM. Despite the impact of TDM in clinical science and its widespread application, TDM has failed to receive the attention it deserves in India. This review intends to bring out a strength, weakness, opportunity and threats (SWOT) analysis for TDM in India so that appropriate steps for fostering the growth of TDM could be envisioned. The need of the hour is the creation of a cooperative group including all the stakeholders, such as TDM professionals, clinicians and the government and devising a National Action Plan to strengthen TDM. Nodal TDM centres should be established, and pilot programmes should be rolled out to identify the thrust areas for TDM in the country, capacity building and creating awareness to integrate TDM into mainstream clinical medicine.

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.

Population pharmacokinetics and dosing regimen optimization of levetiracetam in epilepsy during pregnancy

AIMS

The pharmacokinetics of levetiracetam (LEV) significantly changed during pregnancy. It is a great challenge to predict the adjusted doses of LEV to reach the preconception target concentrations. This study aimed to establish a population pharmacokinetic model of LEV in women with epilepsy (WWE) during pregnancy to analyse the factors of pharmacokinetic variability and to develop a model-based individualized dosing regimen.

METHODS

A total of 166 concentration-time points from 37 WWE during pregnancy treated with LEV were collected to analyse LEV pharmacokinetics with nonlinear mixed-effects modelling. The dosing regimen was optimized by Monte Carlo simulations based on the final model.

RESULTS

The LEV pharmacokinetics in pregnant WWE were best described by a 1-compartment model of first-order absorption and elimination. The population typical value of apparent clearance (CL/F) in the final model was estimated to be 3.82 L/h (95% confidence interval 3.283-4.357 L/h) with a relative standard error of 7.2%. Both total body weight (TBW) and trimester of pregnancy were significantly associated with LEV-CL/F during pregnancy; LEV-CL/F increased by 42.72% when TBW increased from 55 to 65 kg from the first trimester to the second trimester. Monte Carlo simulations showed that dosing regimens for LEV should be individualized based on the patient's TBW and trimester of pregnancy to maximize the likelihood of achieving the therapeutic range.

CONCLUSION

This first population pharmacokinetic study of LEV in WWE during pregnancy supports the use of a weight-based and pregnancy-based dosing regimen and can lay a foundation for further optimizing the individualized dosing regimens.

Clinical value of therapeutic drug monitoring for levetiracetam in pediatric patients with epilepsy

PURPOSE

To identify pediatric patients who require therapeutic drug monitoring (TDM) of levetiracetam (LEV).

METHODS

We retrospectively investigated 2413 routine therapeutic drug monitoring data on serum LEV concentration from 1398 pediatric patients (age, 0-15 years). Samples were grouped by age (infants, < 1 year; preschool children, 1-5 years; primary school children, 6-11 years; and adolescents, 12-15 years), and the LEV concentration-to-dose (CD) ratio was calculated.

RESULTS

The mean CD ratio was highest in adolescents (analysis of variance, p < 0.001); 22.5 % and 15.7 % higher in adolescents than in preschool children and school children, respectively (Scheffé test, p < 0.001); and higher in infants than in preschool children. Preschool children had the lowest ratio and tended to show an increase in the ratio from age 2 to 5 years. Use of enzyme-inducing antiseizure medication reduced the CD ratio by 6.1 % in infants, 12.2 % in preschool children, 5.9 % in primary school children, and 9.4 % in adolescents. The mean CD ratio was 2.7 %, 26.9 %, and 39.3 % higher in preschool children, primary school children, and adolescents with defined chronic kidney disease (CKD) than in the respective age group of patients without CKD. The therapeutic concentration range for a long-term LEV therapy was 11 to 32 μg/mL.

CONCLUSIONS

LEV pharmacokinetics are significantly different between infant and preschool children, so TDM of LEV is clinically useful in these patients. In pediatric patients at higher risk for CKD, glomerular filtration rate and LEV levels should be carefully monitored.

Levetiracetam Therapeutic Drug Monitoring in a Large Cohort of Korean Epileptic Patients

Levetiracetam is a new antiepileptic drug (AED) used for treating and preventing partial or generalized seizures. The usefulness of levetiracetam therapeutic drug monitoring (TDM) is related to inter- or intra-individual pharmacokinetic variability, drug interactions, and patient noncompliance. We aimed to investigate the levetiracetam TDM status in Korean epilepsy patients. Serum trough levetiracetam concentrations were measured using liquid chromatography–tandem mass spectrometry in 710 samples from 550 patients. The median (range) daily and weight-adjusted levetiracetam doses were 1500 (20–5000) mg and 25.5 (3.03–133.0) mg/kg, respectively. Patients on levetiracetam monotherapy constituted only 19.5% of the population, while 30.1% were on co-medication with valproate and 56.0% with enzyme-inducing AEDs (EIAEDs). Observed levetiracetam concentrations were widely distributed, ranging 0.8–95 mg/L, with a median of 17.3 mg/L. Levetiracetam concentrations were therapeutic, supra-therapeutic, and sub-therapeutic in 58.5% (n = 393), 11.6% (n = 78), and 29.9% (n = 201) of samples, respectively. There was a strong correlation between weight-adjusted levetiracetam dosage and concentrations (ρ = 0.6896, p < 0.0001). In this large-scale clinical study, a large inter-individual difference in levetiracetam pharmacokinetics was observed, and levetiracetam concentrations were influenced by EIAEDs. For individual dose adjustments and monitoring compliance, routine levetiracetam TDM is needed in epilepsy patients.

A machine learning approach to personalized dose adjustment of lamotrigine using noninvasive clinical parameters

The pharmacokinetic variability of lamotrigine (LTG) plays a significant role in its dosing requirements. Our goal here was to use noninvasive clinical parameters to predict the dose-adjusted concentrations (C/D ratio) of LTG based on machine learning (ML) algorithms. A total of 1141 therapeutic drug-monitoring measurements were used, 80% of which were randomly selected as the "derivation cohort" to develop the prediction algorithm, and the remaining 20% constituted the "validation cohort" to test the finally selected model. Fifteen ML models were optimized and evaluated by tenfold cross-validation on the "derivation cohort,” and were filtered by the mean absolute error (MAE). On the whole, the nonlinear models outperformed the linear models. The extra-trees’ regression algorithm delivered good performance, and was chosen to establish the predictive model. The important features were then analyzed and parameters of the model adjusted to develop the best prediction model, which accurately described the C/D ratio of LTG, especially in the intermediate-to-high range (≥ 22.1 μg mL⁻¹ g⁻¹ day), as illustrated by a minimal bias (mean relative error (%) =  + 3%), good precision (MAE = 8.7 μg mL⁻¹ g⁻¹ day), and a high percentage of predictions within ± 20% of the empirical values (60.47%). This is the first study, to the best of our knowledge, to use ML algorithms to predict the C/D ratio of LTG. The results here can help clinicians adjust doses of LTG administered to patients to minimize adverse reactions.

Population Pharmacokinetics of Levetiracetam: a Systematic Review

BACKGROUND

The use of levetiracetam (LEV) has been increasing given its favorable pharmacokinetic profile. Numerous population pharmacokinetic studies for LEV have been conducted. However, there are some discrepancies regarding factors affecting its pharmacokinetic variability. Therefore, this systematic review aimed to summarize significant predictors for LEV pharmacokinetics as well as the need for dosage adjustments.

METHODS

We performed a systematic search for population pharmacokinetic studies of LEV conducted using a nonlinear-mixed effect approach from PubMed, Scopus, CINAHL Complete, and Science Direct databases from their inception to March 2020. Information on study design, model methodologies, significant covariate-parameter relationships, and model evaluation was extracted. The quality of the reported studies was also assessed.

RESULTS

A total of 16 studies were included in this review. Only two studies were conducted with a two-compartment model, while the rest were performed with a one-compartment structure. Bodyweight and creatinine clearance were the two most frequently identified covariates on LEV clearance (CLLEV). Additionally, postmenstrual age (PMA) or postnatal age (PNA) were significant predictors for CLLEV in neonates. Only three studies externally validated the models. Two studies conducted pharmacodynamic models for LEV with relatively small sample size.

CONCLUSION

Significant predictors for LEV pharmacokinetics are highlighted in this review. For future research, a population pharmacokinetic-pharmacodynamic model using a larger sample size should be conducted. From a clinical perspective, the published models should be externally evaluated before clinical implementation.

Population Pharmacokinetics of Levetiracetam: A Systematic Review

BACKGROUND

Levetiracetam has been widely used as a treatment option for different types of epilepsy in both adults and children. Because of its large between-subject variability, several population pharmacokinetic studies have been performed to identify its pharmacokinetic covariates, and thus facilitate individualised therapy.

OBJECTIVE

The aim of this review was to provide a synopsis for population pharmacokinetic studies of levetiracetam and explore the identified influencing covariates.

METHODS

We systematically searched the PubMed and Embase databases from inception to 30 June 2020. The information on study designs, target population, model characteristics, and identified covariates was summarised. Moreover, the pharmacokinetic profiles were compared among neonates, children, and adults.

RESULTS

Fourteen studies were included, among which two involved neonates, four involved children, two involved both children and adults, and six involved adults only. The median value of apparent clearance for children (0.074 L/h/kg [range 0.038-0.079]) was higher than that for adults (0.054 L/h/kg [range 0.039-0.061]). Body weight was found to significantly influence the apparent clearance and volume of distribution, whereas renal function influenced the clearance. Likewise, coadministration with enzyme-inducing antiepileptic drugs (such as carbamazepine and phenytoin) increased the drug clearance by 9-22%, whereas coadministration with valproate acid decreased it by 18.8%.

CONCLUSION

Levetiracetam dose regimen is dependent on the body size and renal function of patients. Further studies are needed to evaluate levetiracetam pharmacokinetics in neonates and pregnant women.

Developing precision treatments for epilepsy using patient and animal models

Introduction: Phenytoin was the first antiepileptic drug (AED) discovered in an animal model of seizures whose clinical efficacy was subsequently confirmed. This clearly indicated that a search for other AEDs had to consider animal studies.Areas covered: Main seizure tests used for the evaluation of possible anticonvulsive activity of potential anticonvulsants and their predictive values have been reviewed. Procedures used for the estimation of antiepileptogenic effects have been also included.Expert opinion: First-line seizure models comprise maximal electroshock (MES)-, pentylenetetrazol (PTZ)- and kindling-induced convulsions in rodents. The MES test may be considered as a convenient and easy model of generalized tonic-clonic seizures, PTZ test - as a model of generalized myoclonic seizures and to a certain degree - absence seizures. Kindled seizures (for example, from amygdala) may be regarded as a model of focal seizures. Some tests have been suggested for the search of AEDs effective in drug-resistant seizures - for instance, 6 Hz (44 mA) test or intrahippocampal kainate model of mesial temporal lobe epilepsy. There are also recommendations from experimental epileptology on synergistic AED combinations for patients with drug-resistant seizures. The clinical evidence on this issue is scarce and favors a combined treatment with valproate + lamotrigine.

Closed-loop Neuropharmacology for Epilepsy: Distant Dream or Future Reality?

Epilepsy is considered the most frequent severe neurological condition but most patients treated with medication become seizure free. The management of treatment, however, is highly empirical, mainly relying on observation. A closed-loop therapy for epilepsy would be very valuable for more efficient treatment regimens. Here we discuss monitoring treatment (therapeutic drug monitoring) and the potential developments in this field, as well as providing a review of potential biomarkers that could be used to monitor the disease activity. Finally, we consider the pharmacogenetic input in epilepsy treatment.

Pharmacokinetic and Pharmacodynamic Evaluation of Intravenous Levetiracetam in Children With Epilepsy

This study aimed to evaluate the safety and tolerability of intravenous (IV) levetiracetam (LEV) as a monotherapy in children aged 1 month-16 years and to explore the pharmacokinetics (PK) of IV LEV and the time to seizure after IV then oral administration of LEV in pediatric children with epilepsy. Children diagnosed with acute unprovoked seizures requiring in-hospital IV LEV administration were included. After administration, the clinical seizure outcomes, side effects, and the Korean-Child Behavior Checklist were monitored and the PK and repeated time to seizure were analyzed via modeling using NONMEM software. Overall, 37 children with epilepsy were enrolled and underwent a PK analysis (median age, 4.6 years; median weight, 18.0 kg). Nine children (24.3%) had seizure recurrence during the follow-up period (median, 3.8 months) and 5 children (13.5%) experienced LEV-associated adverse events such as irritability (n = 2; 5.4%) and somnolence (n = 3; 8.1%). The plasma LEV concentrations after IV LEV were best described by a one-compartment linear PK model. Only body weight was associated with both the clearance and volume of distribution of LEV. The Weibull distribution model described the time to seizure recurrence well; no statistically significant predictor for the time to seizure was identified. Therefore, IV LEV was a well-tolerated and effective alternative in children with acute unprovoked seizures, and models for the PK and time to repeated seizure recurrence after LEV were successfully developed. In particular, the current use of a weight-based IV LEV dosing regimen in pediatric children is practical.

A viewpoint on rational and irrational fixed-drug combinations

INTRODUCTION

Considering that there are around 30% of patients with epilepsy resistant to monotherapy, the use of synergistic combinations of antiepileptic drugs is of particular importance. This review shows most beneficial as well as irrational combined treatments both from an experimental and clinical point of view. Areas covered: Preferably, experimental data derived from studies evaluating synergy, additivity, or antagonism by relevant methods, in terms of anticonvulsant or neurotoxic effects and pharmacokinetic data have been considered. Although there have been no randomized clinical trials on this issue, the clinical data have been analyzed from studies on considerable numbers of patients. Case-report studies have been not considered. Expert commentary: The experimental data provide a strong support that co-administration of lamotrigine with carbamazepine is negative, considering the anticonvulsant and neurotoxic effects. Clinical reports do not entirely support this conclusion. Other experimentally documented negative combinations comprise lamotrigine+ oxcarbazepine and oxcarbazepine+ phenytoin. From the experimental and clinical point of view, a combination of lamotrigine+ valproate may deserve recommendation. Other most positive experimental and clinical combinations include carbamazepine+valproate, phenytoin+phenobarbital, carbamazepine+gabapentin, carbamazepine+topiramate, levetiracetam+valproate, levetiracetam+carbamazepine. Certainly, experimental data have some limitations (non-epileptic animals, acute administration of antiepileptic drugs) so all experimental recommendations need a careful clinical evaluation.

Comparison of Plasma, Saliva, and Hair Levetiracetam Concentrations

BACKGROUND

Previous findings revealed high correlations between serum/plasma and saliva levetiracetam concentrations, indicating saliva as an alternative matrix for monitoring levetiracetam therapy. Levetiracetam concentration in the hair, which could reflect long-term drug exposure and patients' compliance, has not been systematically tested, as yet. The aim of this study was to determine the correlation between plasma, saliva, and hair levetiracetam concentrations in 47 patients with epilepsy.

METHODS

Plasma, saliva, and hair levetiracetam concentrations were measured by liquid chromatography-tandem mass spectrometry with positive ionization.

RESULTS

Levetiracetam saliva and plasma concentrations were highly correlated (r = 0.93). Plasma concentrations were not influenced by sex, age, and other concomitant antiepileptic drugs. Levetiracetam hair concentrations correlated with plasma concentrations (r = 0.36) but not daily dose (mg/kg). Drug hair concentrations were not influenced by hair color or treatment (dyed).

CONCLUSIONS

The results tend to indicate that saliva may be a reliable alternative to plasma for monitoring levetiracetam concentrations. Levetiracetam can also be detected in human hair.

Effect of ketogenic diet and other dietary therapies on anti-epileptic drug concentrations in patients with epilepsy

WHAT IS KNOWN AND OBJECTIVE

The ketogenic diet (KD) is an effective high-fat, adequate-protein, low-carbohydrate diet for patients with refractory epilepsy. The aim of this study was to investigate the potential effects of the KD and other dietary therapies on the concentrations of anticonvulsants in patients with epilepsy.

METHODS

Patients with epilepsy who were treated with the KD and other dietary therapies for more than 30 days with at least one measurement performed both before and during the diet were evaluated. The mean serum concentrations and the mean serum concentrations per weight per daily dose per bioavailability (F) of anti-epileptic drugs (AEDs) before and during the treatment were assessed. We also compared the rates of events out of reference ranges of the AEDs between before and during the KD and other dietary therapies. We compared the serum albumin, alanine transaminase and aspartate transaminase data of patients with valproic acid before and during the KD.

RESULTS AND DISCUSSION

One-hundred thirty-nine patients including 81 male patients were enrolled. The median age of the patients was 2.91 (0.15-15.46) years. The median duration of the dietary therapies was 153 (35-2307) days. After the dietary therapies, the serum concentrations of carbamazepine, lamotrigine, levetiracetam, topiramate and valproic acid decreased, whereas that of phenobarbital slightly increased. However, statistical significance was found only with valproic acid (67.07±25.89 μg/mL vs 51.00±20.19 μg/mL, P<.05). The serum concentrations per weight per daily dose per drug F significantly decreased for valproic acid (1.38±1.39×10^-2 vs 0.82±0.82×10^-2  μg d mL^-1  F^-1 ) and phenobarbital (6.66±7.20×10^-2 vs 4.75±4.07×10^-2  μg d mL^-1  F^-1 , P<.05). The rate of occurrence of events out of reference ranges significantly increased with valproic acid (36.08% vs 57.23%, P<.05).

WHAT IS NEW AND CONCLUSIONS

Most anti-epileptic drug serum concentrations remained stable during the KD and other related dietary therapies except those of valproic acid. Therefore, serum concentrations of valproic acid should be monitored when the KD and other dietary therapies are concomitantly administered.

An Analytical Study to Correlate Serum Levels of Levetiracetam with Clinical Course in Patients with Epilepsy

Introduction:

With the advancement of therapeutics, newer antiepileptic drugs (AEDs) like Levetiracetam (LEV), with good therapeutic efficacy and tolerability are available. But unfortunately, therapeutic drug monitoring is not routinely done in India for these drugs.

Objectives:

The objective of this study is to determine the range of serum levels of LEV in patients at stabilized doses and correlate them with their clinical course.

Materials and Methods:

Patients with epilepsy and started on LEV were enrolled from the Neurology Department after the Ethics Committee approval. Serum levels of LEV were estimated using high-performance liquid chromatography and correlated with patient demographics, dosage, dosage forms, concomitant AEDs, compliance of the patient, therapeutic effect, adverse drug reactions (ADRs), and suspected toxicity.

Results:

Serum levels of LEV ranged from 0.4 to 102.2 μg/ml at different time points and demonstrated a negligible positive correlation with age of the patients (r = 0.12) but negligible negative correlation with bodyweight (r = −0.19). No conclusive relationship could be established for dose, gender, dosage forms, clinical efficacy (seizure frequency), ADRs, and toxicity. Compliance was verified in all the patients. Levels were found to reduce with the use of concomitant enzyme inducer drugs (56.78%) whereas increase with valproic acid (7.8%).

Conclusion:

These findings emphasize the need for monitoring the serum levels of newer AEDs like LEV considering the various parameters studied here, so as to maintain the therapeutic efficacy by preventing under or over dosage and to generate a broader database of serum levels of LEV in the Indian population to help appropriate prescribing with more confidence.

Clinical pharmacokinetics: perceptions of hospital pharmacists in Qatar about how it was taught and how it is applied

BACKGROUND

The application of clinical pharmacokinetics (PK) is essential when providing pharmaceutical care. Appropriate application of PK monitoring results in improved patient outcomes including decreased mortality, length of treatment, length of hospital stay, and adverse effects of drug therapy. Despite the well-documented evidence of benefits of clinical PK services, many pharmacists find it challenging to apply PK in clinical practice.

OBJECTIVE

To evaluate pharmacists' training backgrounds, attitude, practices, and perceived barriers pertaining to the application of PK in clinical practice in Qatar.

SETTING

All hospitals under Hamad Medical Corporation, the main healthcare provider in Qatar.

METHODOLOGY

This was a cross-sectional, descriptive study that was conducted between October 2012 and January 2013, using a self-administered web-based survey. Pharmacists were eligible to participate if they: (1) were working as full-time hospital pharmacists and; (2) have been in practice for at least 1 year.

MAIN OUTCOME MEASURES

PK contents learned in undergraduate curriculum; perception towards the PK contents and instructions received in the undergraduate curriculum and; application of PK in current clinical practice.

RESULTS

A total of 112 pharmacists responded to the questionnaire. The majority of the respondents (n = 91; 81.3 %) reported that they had received PK course(s) in their undergraduate curriculum. Similarly, the majority (70-80 %) of them agreed that the undergraduate PK courses or contents they received were important and relevant to their current practice. The pharmacists identified spending more time on dispensing and inventory issues rather than clinical practice, scarce resources, and manual rather than computerized PK calculations as some of the barriers they encountered in learning about PK and its application. The characteristics of the surveyed pharmacists such as gender, age, highest academic degree, and country of graduation did not influence the pharmacists' perception and attitudes towards PK teaching and application (p > 0.05).

CONCLUSION

PK course contents were perceived to lack depth and relevance to practice, and pharmacist had no experiential training that included aspects of PK. These, and other issues, result in poor application of PK in practice.