Population pharmacokinetics of pregabalin in healthy subjects and patients with chronic pain or partial seizures

Pharmacokinetic properties of a new sustained-release pregabalin tablet in subjects with reduced renal function

A new sustained-release (SR) pregabalin tablet, YHD1119, was formulated for once-daily dosing. In the current study, we aimed to evaluate the pharmacokinetics of YHD1119 tablets in patients with reduced renal function. Subjects were grouped by creatinine clearance: > 60 mL/min/1.73m2 (Cohort A) and 30-60 mL/min/1.73m2 (Cohort B). Eight subjects in Cohort A received a YHD1119 75 mg tablet (Y75T) and a YHD1119 150 mg tablet (Y150T) in each period, and eight subjects in Cohort B received a Y75T. Non-compartment analysis and population pharmacokinetic analysis using a one-compartment model with first-order elimination and first-order absorption with lag time were performed. Sixteen subjects completed the study. The geometric mean ratio (GMR) (90% confidence intervals [CI]) for maximum concentration (Cmax), and area under the concentration-time profile from 0 to the last measurable time (AUClast) after Y75T of Cohort B to those of Y75T of Cohort A were 1.2273 (1.0245-1.4701), and 2.4146 (1.8142-3.2138), respectively. The GMR (90% CI) for Cmax, and AUClast after Y75T of Cohort B to those of Y150T of Cohort A were 0.6476 (0.5229-0.8021), and 1.1471 (0.8418-1.5632), respectively. Simulated steady-steady pregabalin concentrations after once-daily Y75T dosing in subjects with eGFR 45 mL/min/1.73 m2 were within the range of steady-state concentrations simulated after once-daily Y150T dosing in subjects with eGFR 90 mL/min/1.73 m2. The total pregabalin exposure of Y75T in patients with moderate renal impairment was comparable with that of Y150T in subjects with near-normal renal function.

Trial Registration

ClinicalTrials.gov Identifier: NCT05012436.

Prenatal Pregabalin Exposure Alters Postnatal Pain Sensitivity and Some Behavioral Responses in Adult Offspring Rats

BACKGROUND

Prenatal antiepileptic drug exposure could demonstrate both congenital malformations and behavioral impairments in offspring.

OBJECTIVE

This study was performed to assess the effects of prenatal exposure to pregabalin (PGB) on pain response, anxiety, motor activity and some behavior of adult offspring rats.

METHODS

Pregnant Wistar rats received PGB (7.5, 15 and 30 mg/kg/ip) during embryonic days 9.5- 15.5. The pain response, anxiety-like behaviors, locomotor activity, motor balance and coordination and anhedonia of adult offspring were examined by tail-flick and hot plate test, open field test, elevated plus maze (EPM), beam balance test and sucrose preference test in their 60th day of life, respectively.

RESULTS

Prenatal exposure to PGB revealed significant dose-dependent reduction in pain sensitivity (increase in pain latency response) in the hot plate test, especially in females, while anxiety-like behavior assessed in EPM and open field significantly reduced in males. In the open field, locomotor activity reduced significantly after exposure to PGB 30 mg/kg and motor coordination decreased dose-dependently, especially in males. Anhedonia, as an indication of sucrose preference or pleasure response, was not changed.

CONCLUSION

These findings suggest that prenatal PGB exposure could be associated with significant changes in pain response, anxiety, locomotor activity and coordination in adult offspring rats.

Pregabalin Population Pharmacokinetic and Exposure-Response Analyses for Focal Onset Seizures in Children (4-16 years) and Adults, to Support Dose Recommendations in Children

Pregabalin is approved in multiple countries as adjunctive therapy for adult patients with focal onset seizures (FOS; previously termed partial onset seizures). This study used population pharmacokinetic (PK) and exposure–response (E‐R) analyses from pooled pregabalin concentration and efficacy data to compare pregabalin exposure and E‐R relationships in pediatric and adult patients with FOS, to support pediatric dosage recommendations. A one‐compartment disposition model was used, with first‐order absorption and body surface area‐normalized creatinine clearance on clearance. Individual pregabalin average steady‐state concentrations were predicted and used in an E‐R analysis of efficacy. The E‐R relationship of pregabalin was similar in pediatric (4–16 years) and adult patients with FOS after accounting for differences in baseline natural log‐transformed 28‐day seizure rate and placebo effect. Population PK simulations showed that children aged 4–16 years and weighing ≥ 30 kg required pregabalin 2.5–10 mg/kg/day to achieve similar pregabalin exposure at steady‐state to adult patients receiving the approved doses of 150–600 mg/day. For children 4–16 years weighing < 30 kg, a higher pregabalin dose of 3.5–14 mg/kg/day was required to achieve equivalent exposure at steady‐state. The results support the dosage guidance provided in the pregabalin prescribing label, whereby pediatric patients (4–16 years) weighing < 30 kg should receive a 40% higher pregabalin dose (per kg of body weight) than patients weighing ≥ 30 kg to achieve similar exposure. Our combined modeling approach may provide guidance for future extrapolation assessment from adult to pediatric patients.

γ-Aminobutyric Acid and Derivatives Reduce the Incidence of Acute Pain after Herpes Zoster - A Systematic Review and Meta-analysis

Herpes zoster (HZ) causes considerable pain and distress, and γ-Aminobutyric acid (GABA) and its derivatives are assumed to control this, but the available data are inconsistent. This meta-analysis and systematic review aimed to assess the effectiveness of GABA derivatives in the prevention of acute herpetic pain. The metaanalysis was conducted following the PRISMA guidelines using PICO format, registered in PROSPERO number CRD42018095758. PubMed, Web of Science, Ovid, Scopus, and EMBASE databases were searched. Records were included if they were randomized controlled trials of patients undergoing HZ infection, investigating the effect of GABA derivatives versus placebo in the treatment of HZ pain. Eligible trials were evaluated for the risk of bias. Then data were extracted and analysed. The number of patients with observed presence of pain after treatment was used to calculate odds ratio in a random effect model with the DerSimonian-Laird estimator. The I2 statistic was analysed for heterogeneity. The potential risk of bias was measured using Egger's regression test. The meta-analysis included three randomized controlled trials with a total of 297 patients. The incidence of acute HZ pain events for GABA group was significantly lower compared to placebo group,18/148 vs 44/149, respectively (OR = 0.36; 95% CI = 0.14 to 0.93; Z = 2.11; P = 0.035), Egger's test yielded P = 0.308. In conclusion, the present meta-analysis demonstrates that GABA derivatives reduce the incidence of acute herpetic pain. However, additional, well-designed randomized clinical trials are needed to determine their dose- and time-dependency regarding this symptom.

Pregabalin in the Management of Painful Diabetic Neuropathy: A Narrative Review

Pregabalin is a first-line treatment in all major international guidelines on the management of painful diabetic neuropathy (pDPN). Treatment with pregabalin leads to a clinically meaningful improvement in pain scores, offers consistent relief of pain and has an acceptable tolerance level. Despite its efficacy in relieving neuropathic pain, more robust methods and comprehensive studies are required to evaluate its effects in relation to co-morbid anxiety and sleep interference in pDPN. The sustained benefits of modulating pain have prompted further exploration of other potential target sites and the development of alternative GABAergic agents such as mirogabalin. This review evaluates the role of pregabalin in the management of pDPN as well as its potential adverse effects, such as somnolence and dizziness, which can lead to withdrawal in ~ 30% of long-term use. Recent concern about misuse and an increase in deaths linked to its use has led to demands for reclassification of pregabalin as a class C controlled substance in the UK. We believe these demands need to be tempered in relation to the difficulties it would create for repeat prescriptions for the many millions of patients with pDPN for whom pregabalin provides benefit.Plain Language Summary: Plain language summary available for this article.

Pharmacokinetics of Single-Dose Oral Pregabalin Administration in Normal Cats

Objective: To describe the pharmacokinetic parameters of oral pregabalin in normal cats after single oral dosing. Animals: Six healthy adult research cats. Procedures: Following sedation and indwelling catheter placement, one oral (4 mg/kg) dose of pregabalin was administered. Blood samples were collected at 0, 15 and 30 min and 1, 1.5, 2, 3, 4, 6, 8, 12, 24, and 36 h after administration. Plasma pregabalin concentrations were measured by high-performance liquid chromatography and subjected to pharmacokinetic analysis using commercial software. Results: Four of six cats developed moderate sedation after pregabalin administration. The peak pregabalin concentration was 8.3 ± 1.6 μg/ml which occurred at 2.9 ± 1.2 h. Elimination half-life was 10.4 ± 2.6 h and area under the curve was 133.9 ± 71.5 μg-h/ml. Time above the minimum therapeutic concentration for seizure control in dogs and people (2.8 μg/ml) was 17.6 ± 6.2 h. Using these data, predicted minimum, maximum and average steady state concentrations were calculated for 12 and 24 h dosing intervals. Conclusions and Clinical Relevance: Pregabalin (4 mg/kg) administered orally to cats results in plasma concentrations within the range considered to be efficacious for seizure control in dogs and humans between 1.5 and at least 12 h. Because of moderate sedative side effects in the majority of cats at this dose and high calculated maximum steady state concentrations, a lower dose, given more frequently (1-2 mg/kg q 12 h), should be evaluated in prospective clinical studies.

Comparison of oral absorption models for pregabalin: usefulness of transit compartment model

Pregabalin is an anticonvulsant used for the treatment of neuropathic pain and partial seizure in adults. The aim of this study was to develop a population pharmacokinetic (PK) model to describe the absorption characteristics of pregabalin given fasted or after meals. Data from five healthy subject PK studies (n=88) of single- or multiple-dose pregabalin (150 mg) were used. Pregabalin was administered twice daily, without meals or 30 min after a meal (regular or high-fat diet) in the morning and 30 min or 4 h after a meal (regular diet) in the evening. Serial plasma samples were collected up to 24 h after the last dose for PK analysis. Because the peak concentrations were not properly modeled by a conventional first-order absorption model, Erlang frequency distribution, Weibull-type absorption, and transit compartment models were tested on a two-compartment linear PK model using a nonlinear mixed-effects method (NONMEM; version 7.3). The transit compartment model best described the absorption characteristics of pregabalin regardless of meal status. We conclude that the absorption model should be carefully chosen based on the principle of model development and validation and not by following a conventional first-order absorption model for its popularity and simplicity, especially when the PK dataset includes densely sampled absorption-phase data.

Predictive Performance of Physiologically Based Pharmacokinetic and Population Pharmacokinetic Modeling of Renally Cleared Drugs in Children

Predictive performance of physiologically based pharmacokinetic (PBPK) and population pharmacokinetic (PopPK) models of drugs predominantly eliminated through kidney in the pediatric population was evaluated. After optimization using adult clinical data, the verified PBPK models can predict 33 of 34 drug clearance within twofold of the observed values in children 1 month and older. More specifically, 10 of 11 of predicted clearance values were within 1.5‐fold of those observed in children between 1 month and 2 years old. The PopPK approach also predicted 19 of 21 drug clearance within twofold of the observed values in children. In summary, our analysis demonstrated both PBPK and PopPK adult models, after verification with additional adult pharmacokinetic (PK) studies and incorporation of known ontogeny of renal filtration, could be applied for dosing regimen recommendation in children 1 month and older for renally eliminated drugs in a first‐in‐pediatric study.

Perampanel efficacy and safety by gender: Subanalysis of phase III randomized clinical studies in subjects with partial seizures

The antiepileptic drug (AED) perampanel is approved in ≥40 countries as adjunctive therapy for drug‐resistant partial seizures in patients with epilepsy. This post hoc analysis of pooled data from three phase III, double‐blind, randomized studies of perampanel examines between‐gender differences in perampanel efficacy and safety. Of the 1,478 subjects in the pooled analysis (719 male, 759 female), 1,109 were included in the pharmacokinetic/pharmacodynamic analysis. Perampanel oral clearance was 17% lower in female than in male patients not receiving enzyme‐inducing AEDs. Pooled efficacy analysis revealed that seizure frequency was reduced with perampanel treatment regardless of gender; a greater numerical reduction in seizure frequency and increased responder rates occurred in female participants at perampanel doses of 4, 8, and 12 mg. Tolerability was similar between groups, although common adverse events such as dizziness and headache occurred more frequently in female subjects. Modest elevations in perampanel exposure in female patients may result in meaningful between‐gender differences in efficacy and safety; therefore, dosing should be individualized and clinical response monitored.

Pharmacokinetic equivalence study of two formulations of the anticonvulsant pregabalin

Purpose

The present study was conducted to evaluate whether the bioavailability of pregabalin capsules 150 mg manufactured by PT Dexa Medica was equivalent to the reference formulation.

Methods

This was a randomized, open-label, two-period, two-sequence, and crossover study under fasting condition, with a 1-week washout period. Plasma concentrations of pregabalin from 20 subjects were determined by using a validated liquid chromatography with tandem mass spectrometry (LC-MS/MS) detection method. Pharmacokinetic parameters assessed in this study were: area under the plasma concentration–time curve from time zero to last observed quantifiable concentration (AUC_0–t), area under the plasma concentration–time curve from time zero to infinity (AUC_0–∞), maximum plasma concentration (C_max), time to maximum plasma concentration (t_max), and terminal half-life (t_1/2). The 90% confidence intervals (CIs) for the geometric mean ratios of test formulation/reference formulation were calculated for the AUC and C_max parameters; while t_max difference was analyzed nonparametrically on the original data using the Wilcoxon matched-pairs test, and t_1/2 difference was analyzed using Student’s paired t-test.

Results

The mean (standard deviation [SD]) AUC_0–t, AUC_0–∞, C_max, and t_1/2 of pregabalin from the test formulation were 27,845.86 (4,508.27) ng · h/mL, 28,311.70 (4,790.55) ng · h/mL, 3,999.71 (801.52) ng/mL, and 5.66 (1.20) hours, respectively; while the mean (SD) AUC_0–t, AUC_0–∞,C_max, and t_1/2 of pregabalin from the reference formulation were 27,398.12 (4,266.28) ng · h/mL, 27,904.24 (4,507.31) ng · h/mL, 3,849.50 (814.50) ng/mL, and 5.87 (1.25) hours, respectively. The median (range) t_max of pregabalin from the test formulation and reference formulation was 1.00 (0.67–2.00) hours and 1.00 (0.67–3.00) hours, respectively. The 90% CIs for the geometric mean ratios of test formulation/reference formulation for pregabalin were 101.54% (98.75%–104.41%) for AUC_0–t, 101.35% (98.66%–104.11%) for AUC_0–∞, and 104.19% (98.75%–109.93%) for C_max.

Conclusion

The study concluded that the two formulations of pregabalin capsules studied were bioequivalent.

Clinical pharmacokinetics of new-generation antiepileptic drugs at the extremes of age: an update

Epilepsies occur across the entire age range, and their incidence peaks in the first years of life and in the elderly. Therefore, antiepileptic drugs (AEDs) are commonly used at the extremes of age. Rational prescribing in these age groups requires not only an understanding of the drugs' pharmacodynamic properties, but also careful consideration of potential age-related changes in their pharmacokinetic profile. The present article, which updates a review published in 2006 in this journal, focuses on recent findings on the pharmacokinetics of new-generation AEDs in neonates, infants, children, and the elderly. Significant new information on the pharmacokinetics of new AEDs in the perinatal period has been acquired, particularly for lamotrigine and levetiracetam. As a result of slow maturation of the enzymes involved in glucuronide conjugation, lamotrigine elimination occurs at a particularly slow rate in neonates, and becomes gradually more efficient during the first months of life. In the case of levetiracetam, elimination occurs primarily by renal excretion and is also slow at birth, but drug clearance increases rapidly thereafter and can even double within 1 week. In general, infants older than 2-3 months and children show higher drug clearance (normalized for body weight) than adults. This pattern was confirmed in recent studies that investigated the pediatric pharmacokinetics of several new AEDs, including levetiracetam, rufinamide, stiripentol, and eslicarbazepine acetate. At the other extreme of age, in the elderly, drug clearance is generally reduced compared with younger adults because of less efficient drug-metabolizing activity, decreased renal function, or both. This general pattern, described previously for several AEDs, was confirmed in recent studies on the effect of old age on the clearance of felbamate, levetiracetam, pregabalin, lacosamide, and retigabine. For those drugs which are predominantly eliminated by renal excretion, aging-related pharmacokinetic changes could be predicted by measuring creatinine clearance (CLCR). Overall, most recent findings confirm that age is a major factor influencing the pharmacokinetic profile of AEDs. However, pharmacokinetic variability at any age can be considerable, and the importance of other factors should not be disregarded. These include genetic factors, co-morbidities, and drug interactions, particularly those caused by concomitantly administered AEDs which induce or inhibit drug-metabolizing enzymes.

Population pharmacokinetics of pregabalin in healthy subjects and patients with post-herpetic neuralgia or diabetic peripheral neuropathy

AIM

Pregabalin, a chemical analogue of the mammalian neurotransmitter γ-aminobutyric acid, has been approved in many countries for partial-onset seizures, generalized anxiety disorder and various other pain disorders, including neuropathic pain associated with post-herpetic neuralgia and diabetic peripheral neuropathy and fibromyalgia. The aim of this study was to develop a population pharmacokinetic model and quantify the influence of covariates on the parameters.

METHODS

This pregabalin population pharmacokinetic analysis was conducted on data from 14 clinical trials involving healthy subjects, subjects with impaired renal function and patients with post-herpetic neuralgia or diabetic peripheral neuropathy (n= 616). The data analysis was performed using nonlinear mixed effects modelling methodology as implemented by NONMEM.

RESULTS

A one-compartment model with first-order absorption and elimination adequately described pregabalin pharmacokinetics. The model indicated that pregabalin apparent clearance (CL/F) was proportional to estimated creatinine clearance (CL(cr) ). The pregabalin systemic exposure in patients with lower renal function who received pregabalin 150 mg twice daily was almost equal to that of patients with normal renal function administered pregabalin 300 mg twice daily. The systemic exposure stratified by lower or normal renal function was similar between patients with post-herpetic neuralgia and diabetic peripheral neuropathy.

CONCLUSION

The developed model identified CL(cr) and ideal body weight as clinically influential covariates on CL/F and volume of distribution, respectively. This study indicates that renal function accounts for variability in the apparent clearance of pregabalin which is consistent with what is known about the elimination of this drug.