Safety, tolerability, and pharmacokinetics of pregabalin in children with refractory partial seizures: A phase 1, randomized controlled study

Current Status of Pharmacokinetic Research in Children: A Systematic Review of Clinical Trial Records

BACKGROUND

Many medications have different pharmacokinetics in children than in adults. Knowledge about the safety and efficacy of medications in children requires research into the pharmacokinetic profiles of children's medicines. By analysing registered clinical trial records, this study determined how frequently pharmacokinetic data is gathered in paediatric drug trials.

METHODS

We searched for the pharmacokinetic data from clinical trial records for preterm infants and children up to the age of 16 from January 2011 to April 2022. The records of trials involving one or more drugs in preterm infants and children up to the age of 16 were examined for evidence that pharmacokinetic data would be collected.

RESULTS

In a total of 1483 records of interventional clinical trials, 136 (9.17%) pharmacokinetic data involved adults. Of those 136 records, 60 (44.1%) records were pharmacokinetics trials involving one or more medicines in children up to the age of 16. 20 (33.3 %) in America, followed by 19 (31.6 %) in Europe. Most trials researched medicines in the field of infection or parasitic diseases 20 (33.3%). 27 (48.2%) and 26 (46.4%) trials investigated medicines that were indicated as essential medicine.

CONCLUSION

The pharmacokinetic characteristics of children's drugs need to be better understood. The current state of pharmacokinetic research appears to address the knowledge gap in this area adequately. Despite slow progress, paediatric clinical trials have experienced a renaissance as the significance of paediatric trials has gained international attention. The outcome of paediatric trials will have an impact on children's health in the future. In recent years, the need for greater availability and access to safe child-size pharmaceuticals has received a lot of attention.

A single injection of pregabalin induces short- and long-term beneficial effects on fear memory and anxiety-like behavior in rats with experimental type-1 diabetes mellitus

Anxiety Disorders and Posttraumatic Stress Disorders (PTSD) associated with type-1 diabetes mellitus (T1DM) are increasingly common comorbidities and the treatment is quite challenging. In that sense, evidence indicates that the anticonvulsant pregabalin is highly effective in treating severe cases of anxiety, as well as PTSD and diabetic neuropathic pain which is also very prevalent in T1DM. Herein, the short- and long-term effects of a single injection of pregabalin on the acquisition of a fear extinction memory and parameters of anxiety in induced-T1DM animals were investigated. For that, we used the contextual fear conditioning (CFC) and elevated plus maze paradigms, respectively. A putative antioxidant activity was also evaluated. Our findings demonstrated that induced-T1DM animals presented greater expression of fear memory, difficulty in extinguishing this fear memory, associated with a more pronounced anxiety-like response. Pregabalin was able to induce a short and long-lasting effect by facilitating the acquisition of the fear extinction memory and inducing a later anxiolytic-like effect. Also, the increased lipid peroxidation levels in the hippocampus and prefrontal cortex of induced-T1DM rats were reduced after pregabalin injection, while the decreased levels of reduced glutathione were increased in the hippocampus. Despite the need for more studies to understand the mechanism of action of pregabalin under these conditions, our data demonstrate for the first time that a single injection of pregabalin in a specific time window was able to improve behavioral parameters in addition to inducing neuroprotective effect. Thus, pregabalin has potential worth exploring for the treatment of PTSD and/or Anxiety associated with T1DM.

Extracorporeal Treatment for Gabapentin and Pregabalin Poisoning: Systematic Review and Recommendations From the EXTRIP Workgroup

Toxicity from gabapentin and pregabalin overdose is commonly encountered. Treatment is supportive, and the use of extracorporeal treatments (ECTRs) is controversial. The EXTRIP workgroup conducted systematic reviews of the literature and summarized findings following published methods. Thirty-three articles (30 patient reports and 3 pharmacokinetic studies) met the inclusion criteria. High gabapentinoid extracorporeal clearance (>150mL/min) and short elimination half-life (<5 hours) were reported with hemodialysis. The workgroup assessed gabapentin and pregabalin as "dialyzable" for patients with decreased kidney function (quality of the evidence grade as A and B, respectively). Limited clinical data were available (24 patients with gabapentin toxicity and 7 with pregabalin toxicity received ECTR). Severe toxicity, mortality, and sequelae were rare in cases receiving ECTR and in historical controls receiving standard care alone. No clear clinical benefit from ECTR could be identified although major knowledge gaps were acknowledged, as well as costs and harms of ECTR. The EXTRIP workgroup suggests against performing ECTR in addition to standard care rather than standard care alone (weak recommendation, very low quality of evidence) for gabapentinoid poisoning in patients with normal kidney function. If decreased kidney function and coma requiring mechanical ventilation are present, the workgroup suggests performing ECTR in addition to standard care (weak recommendation, very low quality of evidence).

Development of Physiologically Based Pharmacokinetic Model for Pregabalin to Predict the Pharmacokinetics in Pediatric Patients with Renal Impairment and Adjust Dosage Regimens: PBPK Model of Pregabalin in Pediatric Patients with Renal Impairment

Pregabalin (PGB) is widely used clinically; however, its pharmacokinetics (PK) has not been studied in pediatric patients with renal impairment (RI). To design optimized PGB regimens for pediatric patients with varying degrees of RI and predict exposure to PGB, physiologically based pharmacokinetic (PBPK) models of PGB were developed and verified, and its disposition was simulated in the healthy population and adults with RI. The simulated results from the PBPK models after single-dose and multi-dose administrations of PGB were consistent with the corresponding observed data based on the fold error values of less than 2. The area under curve ratios were 1.23 ± 0.06, 2.02 ± 0.10, 3.86 ± 0.21, and 9.92 ± 0.79 in pediatric patients with mild, moderate, severe, and end-stage RI, respectively. Based on the predictions for pediatric patients with moderate, severe, and end-stage RI, the maximum dose should not exceed 7, 3.5, and 1.4 mg/kg/day, respectively, among those weighing < 30 kg, and it should not exceed 5, 2.5, and 1 mg/kg/day, respectively, among those weighing > 30 kg. In conclusion, the developed PBPK model is a valuable tool for predicting PGB dosage for pediatric patients with RI.

Drug Repositioning: Antimalarial Activities of GABA Analogs in Mice Infected with Plasmodium berghei

BACKGROUND

Drug repositioning is becoming popular due to the development of resistance to almost all the recommended antimalarials. Pregabalin and gabapentin are chemical analogs of gamma- aminobutyric acid (GABA) approved for the treatment of epilepsy and neuropathic pain.

OBJECTIVE

This study investigates acute toxicities and antimalarial activities of pregabalin and gabapentin in the murine malarial model.

METHODS

Acute toxicities were assessed using the method of Lorke, while curative activities were assessed by the administration of serial doses of pregabalin and gabapentin to Plasmodium berghei infected mice. Pregabalin was further investigated for its prophylactic activity, and curative potential when combined with either artesunate or amodiaquine. All drugs were freshly prepared and administered orally. Thin films were collected, stained, and observed under the microscope for the estimation of parasitemia and calculation of percentage chemoinhibition or chemoprevention. In pregabalin -artesunate or -amodiaquine combination aspect of this study, survival day post-infection (SDPI) was recorded, while parasitemia was re-estimated for animals that survived till day 28.

RESULTS

The oral LD50 of gabapentin, as well as pregabalin, was >5,000 mg/kg. Gabapentin at 100 and 200 mg/Kg demonstrated 35.64% and -12.78% chemoinhibition, respectively, while pregabalin demonstrated 75.60% and 100.00% chemoinhibition at doses of 12.5 and 25 mg/Kg, respectively. Moreover, pregabalin at individual doses of 25, 50 mg/Kg, and in combination with either artesunate or amodiaquine demonstrated 100.00% chemoinhibition. In its prophylactic study, pregabalin was found to be 100% chemopreventive at individual doses of 12.5 and 25 mg/Kg.

CONCLUSION

Both GABA analogs have antimalarial properties, but pregabalin proved to be more efficacious.

Pregabalin as adjunctive therapy in adult and pediatric patients with generalized tonic-clonic seizures: A randomized, placebo-controlled trial

OBJECTIVE

Generalized tonic-clonic (GTC) seizures are the most common type of generalized seizure and more common in children than adults. This phase 3 study evaluated the efficacy and safety of pregabalin for GTC seizures in adults and children with epilepsy.

METHODS

This randomized, double-blind, multicenter study evaluated pregabalin (5 mg/kg/day or 10 mg/kg/day) vs placebo as adjunctive therapy for 10 weeks (following a 2-week dose escalation), in pediatric and adult patients (aged 5-65 years) with GTC seizures. Primary endpoint was change in log-transformed 28-day seizure rate during active treatment. Secondary endpoints included responder rates, defined as proportion of patients with ≥50% reduction in 28-day GTC seizure rate from baseline. Safety was monitored throughout.

RESULTS

Of 219 patients, 75, 72, and 72 were randomized to adjunctive pregabalin 5 mg/kg/day, 10 mg/kg/day, and placebo, respectively. Fifteen, 11, and 6 patients discontinued from the 5 mg/kg/day, 10 mg/kg/day, and placebo arms, respectively, most commonly due to adverse events (AEs; 10.7%, 6.9%, and 5.6%, respectively). A nonsignificant change in log-transformed mean 28-day seizure rate was seen with pregabalin 10 mg/kg/day vs placebo (least-squares [LS] mean difference -0.01 [95% confidence interval (CI) -0.19 to 0.16]; P = .8889) and with pregabalin 5 mg/kg/day vs placebo (LS mean difference 0.02 [CI -0.15 to 0.19]; P = .8121). Similar observations were noted for adults and children. No significant differences were seen for secondary endpoints with pregabalin vs placebo, including responder rate. The most common AEs (≥10%) were dizziness, headache, and somnolence. Most were of mild/moderate intensity. Seven patients had serious AEs, with one death in the placebo arm (sudden unexpected death in epilepsy).

SIGNIFICANCE

Adjunctive pregabalin treatment did not change GTC seizure rate in adults or children. The safety profile of pregabalin was similar to that known; treatment was well tolerated with few discontinuations due to AEs.

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.

Unintentional exposure to pregabalin in ≤6-year-old children: a nationwide French Poison Control Center study

INTRODUCTION

In France, pregabalin is widely prescribed in adults but still not approved for children. We aimed to investigate the incidence of pregabalin exposure in ≤6-year-old children, to describe the characteristics and outcome of ingestions involving pregabalin alone, and to estimate a clinically relevant toxic dose in this population.

METHODS

Retrospective analysis of pregabalin exposures in ≤6-year-old children, collected by the French Poison Control Centers in 2004-2019. The incidence was estimated using pregabalin prescription data from the Health Improvement Network database (the French version of THIN). The poison severity score (PSS) was used to grade severity.

RESULTS

We found 313 unintentional immediate-release pregabalin ingestions in ≤6-year-old children. The number of cases per 100,000 pregabalin-treated adults increased over time (p < 0.001). One hundred twenty-six cases involving pregabalin alone (age, 2 years [1.6-3.0] (median [25th-75th percentiles]); median ingested dose 6.4 mg/kg [3.6-10.9]) were analyzed. No child presented an underlying neurological/cardiac disease and/or took concomitant medications. Most of the children (77%) remained asymptomatic (PSS0) while 21% and 2% developed minor (PSS1) or moderate (PSS2) neurological symptoms, respectively. No severe complications/fatalities were reported. All symptomatic children recovered within 24 h. The ingested pregabalin dose was positively correlated with PSS (p < 0.0001). Using a ROC curve approach (area under the curve, 0.85; p < 0.001), ingestion of ≥19.4 mg/kg pregabalin was appropriate to recommend hospital referral (sensitivity, 39% [95% confidence interval (95% CI), 24-56], specificity, 100% [95% CI, 96-100], predictive positive value, 100% [95% CI, 64-100], and negative predictive value, 85% [95% CI, 82-89]). Symptomatic children who ingested <19.4 mg/kg pregabalin developed minor symptoms.

CONCLUSION

Despite increasing prescriptions in adults in France, unintentional pregabalin ingestions in ≤6-year-old children remain rare and cause minimal toxicity. Children with no underlying neurological/cardiac disease and concomitant medication ingesting <19.4 mg/kg immediate-release pregabalin alone can be safely observed at home.

Consensus statements on the clinical uses of pregabalin for Hong Kong

To facilitate the understanding of pregabalin and optimize its clinical usage in Hong Kong, an expert panel (11 psychiatrists, one family physician and one anesthesiologist) experienced in treating anxiety and somatic symptoms was invited to establish a set of consensus statements based on several discussion areas. A non-systematic literature search for relevant articles was conducted. The panelists addressed the discussion areas by sharing their clinical experience and available literature in a couple of meetings. At the last meeting, consensus statements derived from the proceedings were discussed and finalized. A total of 11 statements were ultimately accepted by panel voting based on their practicability of recommendation in Hong Kong. These statements are aimed to act as a practical reference for local clinicians when they consider prescribing pregabalin in different clinical situations.

Pregabalin adjunctive therapy for focal onset seizures in children 1 month to <4 years of age: A double-blind, placebo-controlled, video-electroencephalographic trial

OBJECTIVE

To evaluate the efficacy and safety of pregabalin as adjunctive treatment for children (aged 1 month-<4 years) with focal onset seizures (FOS) using video-electroencephalography (V-EEG).

METHODS

This randomized, placebo-controlled, international study included V-EEG seizure monitoring (48-72 hours) at baseline and over the last 3 days of 14-day (5-day dose escalation; 9-day fixed dose) double-blind pregabalin treatment (7 or 14 mg/kg/d in three divided doses). This was followed by a double-blind 1-week taper. The primary efficacy endpoint was log-transformed seizure rate (log_e [24-hour seizure rate + 1]) for all FOS recorded during the double-blind V-EEG monitoring, evaluated in subjects who took ≥1 dose of study medication, experienced ≥1 baseline seizure(s), and had a treatment phase V-EEG. Safety and tolerability were assessed by adverse events (AEs), clinical laboratory data, physical/neurological examinations, vital signs, and electrocardiograms.

RESULTS

Overall, 175 patients were randomized (mean age = 28.2 months; 59% male, 69% white, 30% Asian) in a 2:1:2 ratio to pregabalin 7 or 14 mg/kg/d (n = 71 or n = 34, respectively), or placebo (n = 70). Pregabalin 14 mg/kg/d (n = 28) resulted in a statistically significant 35% reduction of log_e (24-hour seizure rate + 1) versus placebo (n = 53; P = .022), an effect that was not observed with pregabalin 7 mg/kg/d (n = 59; P = .461). The most frequently reported treatment-emergent AEs for pregabalin 7 mg/kg/d, 14 mg/kg/d, and placebo, respectively, were somnolence (11.3%, 17.6%, and 5.7%) and upper respiratory tract infection (7.0%, 11.8%, and 11.4%). All AEs were mild to moderate in severity.

SIGNIFICANCE

Pregabalin 14 mg/kg/d (but not 7 mg/kg/d) significantly reduced seizure rate in children with FOS, when assessed using V-EEG, compared with placebo. Both pregabalin dosages were generally safe and well tolerated in children 1 month to <4 years of age with FOS. Safety and tolerability were consistent with the known profile of pregabalin in older children with epilepsy.

Preemptive Pregabalin in Children and Adolescents Undergoing Posterior Instrumented Spinal Fusion: A Double-Blinded, Placebo-Controlled, Randomized Clinical Trial

BACKGROUND

Pregabalin as part of a multimodal pain-management regimen has been shown to reduce opioid consumption after spinal surgery in adults but it is unclear whether this is also true in adolescents. Pregabalin has been found to have neuroprotective effects and therefore could have a positive impact on pain after spinal deformity surgery. We conducted a randomized, double-blinded, placebo-controlled clinical trial of adolescent patients undergoing spinal fusion to evaluate the short-term effects of pregabalin on postoperative pain and opioid consumption.

METHODS

Adolescents with adolescent idiopathic scoliosis, Scheuermann kyphosis, or spondylolisthesis who were scheduled for posterior spinal fusion with all-pedicle-screw instrumentation were randomized to receive either pregabalin (2 mg/kg twice daily) or placebo preoperatively and for 5 days after surgery. The patients ranged from 10 to 21 years of age. The primary outcome was total opioid consumption as measured with use of patient-controlled analgesia. Postoperative pain scores and opioid-related adverse effects were evaluated.

RESULTS

Sixty-three of 77 eligible patients were included and analyzed. Cumulative oxycodone consumption per kilogram did not differ between the study groups during the first 48 hours postoperatively, with a median of 1.44 mg/kg (95% confidence interval [CI],1.32 to 1.67 mg/kg) in the pregabalin group and 1.50 mg/kg (95% CI, 1.39 to 1.79 mg/kg) in the placebo group (p = 0.433). A subgroup analysis of 51 patients with adolescent idiopathic scoliosis showed the same result, with a mean of 1.45 mg/kg (95% CI, 1.24 to 1.65 mg/kg) in the pregabalin group and 1.59 mg/kg (95% CI, 1.37 to 1.82 mg/kg) in the placebo group (p = 0.289). Total oxycodone consumption per hour (mg/kg/hr) was not different between the groups over the time points (p = 0.752). The postoperative pain scores did not differ significantly between the groups (p = 0.196).

CONCLUSIONS

The use of perioperative pregabalin does not reduce the postoperative opioid consumption or pain scores in adolescents after posterior spinal fusion surgery.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Pregabalin as Adjunctive Treatment for Focal Onset Seizures in Pediatric Patients: A Randomized Controlled Trial

Efficacy and safety of pregabalin as adjunctive treatment for children (aged 4-16 years) with partial-onset seizures, hereafter termed focal onset seizures for this study, was evaluated. This double-blind, randomized, placebo-controlled, international study had 3 phases: 8-week baseline, 12-week double-blind treatment (2-week dose escalation; 10-week fixed dose), and 1-week taper. Selection criteria included experiencing focal onset seizures and receiving a stable regimen of 1 to 3 antiepileptic drugs. Study treatments were pregabalin 2.5 mg/kg/d, 10 mg/kg/d, or placebo; doses were increased to 3.5 or 14 mg/kg/d for subjects weighing <30 kg. The key endpoints were change in log_e(28-day seizure rate), achieving a ≥50% seizure responder rate, safety, and tolerability during double-blind treatment. Subjects (n = 295; mean age 10.2 years, 55% male, 69% white) were randomized to pregabalin 2.5 mg/kg/d (n = 104), 10 mg/kg/d (n = 97), or placebo (n = 94). A statistically significant reduction in log_e(28-day seizure rate) was demonstrated with pregabalin 10 mg/kg/d (a 19.9% improvement over placebo; P = .0185). Seizure frequency was numerically improved (statistically nonsignificant) with pregabalin 2.5 mg/kg/d ( P = .2577). Responder rate significantly favored pregabalin 10 mg/kg/d (40.6%, P = .0068) compared with placebo (22.6%) and was numerically improved with pregabalin 2.5 mg/kg/d (29.1%, P = .2600). Common adverse events (≥10% of any group) in 10 mg/kg/d, 2.5 mg/kg/d, and placebo groups, respectively, included somnolence (25.8%, 17.3%, 13.8%), increased weight (13.4%, 3.8%, 4.3%), and increased appetite (10.3%, 6.7%, 4.3%). Pregabalin 10 mg/kg/d demonstrated efficacy in seizure frequency reduction in children with focal onset seizures compared with placebo, and both pregabalin doses were generally safe and well tolerated. www.clinicialtrials.gov identifier NCT01389596; EudraCT #2010-020852-79.

Effect of Pregabalin Premedication on Emergence Agitation in Children after Sevoflurane Anesthesia: A Randomized Controlled Study

Background:

Emergence agitation (EA) is common in pediatrics after sevoflurane anesthesia.

Aims:

We intended to study the effect of preoperative pregabalin on EA in pediatrics after sevoflurane anesthesia.

Settings and Design:

This study design was a prospective randomized controlled double-blinded study.

Patients and Methods:

Sixty children with American Society of Anesthesiologists physical status Classes I–II, aged 4–10 years, prepared for adenotonsillectomy under sevoflurane anesthesia were randomized to two equal groups (control Group C and pregabalin Group P). Children received either placebo syrup (Group C) or pregabalin syrup 1.5 mg/kg (Group P) ½ h preoperatively. We recorded postoperative EA scale (EAS) (10, 20, and 30 min postoperatively), time to open the eye, time to extubate, postanesthesia care unit (PACU) duration of stay, number of paracetamol doses (15 mg/kg) given (to control postoperative pain), and complications as vomiting and dizziness on discharge.

Statistical Analysis Used:

Independent sample t-test and Chi-square test were used as appropriate.

Results:

Pregabalin Group P showed less EAS, less analgesic (paracetamol) requirement, and less vomiting with insignificant effects on time to open the eye or extubation and PACU duration of stay compared to control group.

Conclusion:

Preoperative pregabalin decreased postoperative EAS, analgesic (paracetamol) requirement, and vomiting in pediatrics after adenotonsillectomy using sevoflurane anesthesia without affecting time to open the eye or extubation and PACU duration of stay.

Preoperative pregabalin has no effect on intraoperative neurophysiological monitoring in adolescents undergoing posterior spinal fusion for spinal deformities: a double-blind, randomized, placebo-controlled clinical trial

PURPOSE

This study was designed to evaluate the effect of preoperative pregabalin on intraoperative neurophysiological monitoring in adolescents undergoing surgery for spinal deformities.

METHODS

Thirty-one adolescents undergoing posterior spinal fusion were randomized to receive preoperatively either pregabalin 2 mg/kg twice daily or placebo. The ability to make reliable intraoperative neurophysiological measurements, transcranial motor (MEPs) and sensory evoked potentials (SSEP) was evaluated.

RESULTS

Two patients (pregabalin group) did not fulfil the inclusion criteria and one patient's (placebo group) spinal monitoring was technically incomplete and these were excluded from the final data. In the rest, spinal cord monitoring was successful. Anaesthesia prolonged the latency of MEPs and increased the threshold current of MEP. The current required to elicit MEPs did not differ between the study groups. There were no statistically significant differences between the study groups regarding the latency of bilateral SSEP (N32 and P37) and MEP latencies at any time point.

CONCLUSIONS

Preoperative pregabalin does not interfere spinal cord monitoring in adolescents undergoing posterior spinal fusion.

LEVEL OF EVIDENCE

I.

Pregabalin as adjunct in a multimodal pain therapy after traumatic foot amputation — A case report of a 4-year-old girl

Background and purpose

The purpose of this case report is to describe a multimodal pain therapeutic concept including the adjunct use of pregabalin in a 4.5 year-old child after forefoot amputation.

Phantom limb pain and sensation is a complex pain syndrome that is difficult to treat and prevent. 70–75% of all children develop such a pain syndrome after amputation. We describe here a paediatric patient who underwent forefoot amputation following traumatic foot injury and received multimodal pain therapy including pregabalin.

The current experiment aimed at studying effects of empathic communication, and more specifically validation, on recall during a pain test and possible mediators and moderators of this effect.

Methods

A 4.5 year-old otherwise healthy girl suffered severe injuries of the right foot and lower leg during a motor vehicle accident. Due to development of severe necrosis, forefoot amputation had to be performed during the hospital stay.

Results

Initial pain therapy included paracetamol, ibuprofen, metamizol, morphine and fentanyl. With mounting pain and anxiety, regional anaesthesia of the distal sciatic nerve was administered in combination with a ketamine and morphine patient controlled analgesia pump (PCA). The peripheral blockade of the distal sciatic nerve was placed with the guidance of ultrasound and nerve stimulator. The PCA concept included a continuous basal rate combined with a bolus function. Although the regional anaesthesia was well positioned and functioning, there was inadequate pain control. The pain was described by the patient as short, highly intense and sharp sensations with intensity on the visual analogue scale (VAS) of 10 (out of 10). Furthermore, she suffered from anxiety episodes and sleep disturbance. The medical team decided to treat with pregabalin to resolve these issues while awaiting amputation (Lisfranc line). She received psychological counselling as adjunct treatment. This multimodal concept enabled an early and efficient pain reduction pre- and post-amputation and allowed for the possibility of a hospital discharge without any opioid pain medication.

Conclusion

The multimodal pain therapy including pregabalin was well tolerated, safe and highly effective in this case of traumatic limb injury and subsequent amputation. The use of pregabalin allowed significant pain and anxiety reduction for the patient.

Implications

Pregabalinis frequentlyused in adult patients for severe complex pain syndromes. There are only few reports of such adjunct medication (pregabalin) in paediatric pain syndromes. These reports focus mainly on the paediatric oncologic population. The case reported here encourages physicians to consider adjunct medications when treating complex pain, which are well established in the adult population. The benefits of such therapy in complex pain and anxiety can be extended to the paediatric population in select cases. Of course, one must always take into account that many routine medications used in children are well established but are off-label use. The authors are well aware of this problem and have conducted a critical literature review prior to pregabalin administration, including the search for randomized trials examining safety and tolerability. The parents or legal guardians of a minor must be thoroughly informed and consent to such a constellation of medical treatment.

Preparation and evaluation of floating tablets of pregabalin

Floating tablets of pregabalin were prepared using different concentrations of the gums (xanthan gum and guar gum), Carbopol 974P NF and HPMC K100. Optimized formulations were studied for physical tests, floating time, swelling behavior, in vitro release studies and stability studies. In vitro drug release was higher for tablet batches containing guar and xanthan gum as compared to the batches containing Carbopol 974P NF. Tablet batches were subjected to stability studies and evaluated by different parameters (drug release, drug content, FTIR and DSC studies). The optimized tablet batch was selected for in vivo pharmacodynamic studies (PTZ induced seizures). The results obtained showed that the onset of jerks and clonus were delayed and extensor phase was abolished with time in treated groups. A significant difference (p > 0.05) was observed in control and treated group behavior indicating an excellent activity of the formulation for a longer period (>12 h).

Pediatric Sleep Pharmacology: A Primer

"What will you give my child to help him sleep?" is a common question parents ask and some health care providers abhor hearing. Entire families may suffer when one member does not sleep well. Poor sleep may complicate the management of other comorbid conditions. Health care providers may have received only limited education on sleep disorders and are frequently forced to choose between treatment options that are poorly studied in children. Fortunately, when addressed correctly, many children with chronic sleep disorders may improve their sleep and daytime behavior in a relatively short time. This review provides a framework to help understand the causes of poor sleep in children and the potential pharmacologic options.