Effect of pregabalin initiation on diuretic requirements in patients with chronic heart failure.

BACKGROUND: Literature on pregabalin use in patients with heart failure is largely limited to patient case reports and cohort studies. OBJECTIVE: This study aimed to evaluate the effect of pregabalin initiation on diuretic requirements in patients with heart failure. METHODS: A retrospective analysis of patients with heart failure who were started on pregabalin between January 1, 2014, and September 1, 2021, at the Veterans Affairs North Texas Health Care System was used. The primary objective was to determine the median change in loop diuretic dose, in furosemide dose equivalents, 6 months after pregabalin initiation. RESULTS: Of 58 patients analyzed, there was no statistically significant difference in the primary outcome (P = 0.162). The secondary outcomes were found to be nonstatistically significant, and there was no correlation between pregabalin dose and outcomes. CONCLUSION: This represents the largest analysis of diuretic dose requirements in patients with heart failure after initiation of pregabalin. Although there was no difference in the median change of diuretic dose prescribed, pregabalin should still be used with caution.

Pathogenic Mechanism of Dry Eye-Induced Chronic Ocular Pain and a Mechanism-Based Therapeutic Approach.

Purpose: Dry eye-induced chronic ocular pain is also called ocular neuropathic pain. However, details of the pathogenic mechanism remain unknown. The purpose of this study was to elucidate the pathogenic mechanism of dry eye-induced chronic pain in the anterior eye area and develop a pathophysiology-based therapeutic strategy. Methods: We used a rat dry eye model with lacrimal gland excision (LGE) to elucidate the pathogenic mechanism of ocular neuropathic pain. Corneal epithelial damage, hypersensitivity, and hyperalgesia were evaluated on the LGE side and compared with the sham surgery side. We analyzed neuronal activity, microglial and astrocytic activity, α2δ-1 subunit expression, and inhibitory interneurons in the trigeminal nucleus. We also evaluated the therapeutic effects of ophthalmic treatment and chronic pregabalin administration on dry eye-induced ocular neuropathic pain. Results: Dry eye caused hypersensitivity and hyperalgesia on the LGE side. In the trigeminal nucleus of the LGE side, neuronal hyperactivation, transient activation of microglia, persistent activation of astrocytes, α2δ-1 subunit upregulation, and reduced numbers of inhibitory interneurons were observed. Ophthalmic treatment alone did not improve hyperalgesia. In contrast, continuous treatment with pregabalin effectively ameliorated hypersensitivity and hyperalgesia and normalized neural activity, α2δ-1 subunit upregulation, and astrocyte activation. Conclusions: These results suggest that dry eye-induced hypersensitivity and hyperalgesia are caused by central sensitization in the trigeminal nucleus with upregulation of the α2δ-1 subunit. Here, we showed that pregabalin is effective for treating dry eye-induced ocular neuropathic pain even after chronic pain has been established.

A randomized comparative study of methylcobalamin, methylcobalamin plus pregabalin and methylcobalamin plus duloxetine in patients of painful diabetic neuropathy.

CONTEXT: Diabetic neuropathy affects 10.5%-32.2% of diabetic population posing clinical burden onto society. AIMS: We aimed to study the efficacy, safety, and tolerability of methylcobalamin, methylcobalamin plus pregabalin, and methylcobalamin plus duloxetine in patients of painful diabetic neuropathy. SETTINGS AND DESIGN: It is a prospective, randomized, open-label, interventional, and parallel-group study done in patients of painful diabetic neuropathy. MATERIALS AND METHODS: A total of 100 patients were recruited and randomized to three study groups A, B, and C on methylcobalamin, methylcobalamin and pregabalin, and methylcobalamin and duloxetine, respectively. Patients were assessed at day 0 and 4, 8, and 12 weeks. The tuning fork test, monofilament test, Thermal Sensitivity testing, and Visual Analog Scale (VAS) were used to analyze vibration, pressure, thermal sensitivity, and pain. STATISTICAL ANALYSIS USED: The results are expressed as mean ± standard deviation. Appropriate statistical methods were used to calculate P value (<0.05 - significant). RESULTS: The increase in number of patients with vibration perception is 11.6%, 37.9%, and 41.4%; pressure sensation is 7.6%, 37.9%, and 37.9%; and thermal sensitivity is 15.4%, 31.1%, and 37.9% in Groups A, B, and C, respectively. The decrease in VAS scores is 0.58 ± 0.14, 3.82 ± 0.05, and 4.17 ± 0.48 in Groups A, B, and C correspondingly. The adverse effects reported in Groups A, B, and C are 0%, 6.9%, and 10.3%, respectively. CONCLUSIONS: Group C is more efficacious when compared to Groups A and B while Group B is safer.

The analgesic efficacy of pregabalin for shoulder arthroscopy: A meta-analysis of randomized controlled trials.

INTRODUCTION: The efficacy of pregabalin for pain management of shoulder arthroscopy remains controversial. We conduct this meta-analysis to explore the influence of pregabalin versus placebo on the postoperative pain intensity of shoulder arthroscopy. METHODS: We have searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through November 2019 for randomized controlled trials assessing the effect of pregabalin versus placebo on pain control of shoulder arthroscopy. This meta-analysis was performed using the random-effect model. RESULTS: Three randomized controlled trials were included in the meta-analysis. Overall, compared with control group for shoulder arthroscopy, pregabalin remarkably decreased pain scores at 0 to 1 hour (Std. MD = -0.57; 95% CI = -1.04 to -0.09; P = .02) and 12 hours (Std. MD = -0.37; 95% CI = -0.72 to -0.02; P = .04), as well as analgesic consumption (Std. MD = -1.84; 95% CI = -2.24 to -1.44; P < .00001), but showed no notable influence on pain scores at 24 hours (Std. MD = -0.54; 95% CI = -1.47 to 0.38; P = .25), nausea or vomiting (RR = 0.84; 95% CI = 0.53-1.33; P = .45), dizziness (RR = 1.14; 95% CI = 0.89-1.47; P = .30). CONCLUSIONS: Pregabalin may benefit to pain control after shoulder arthroscopy.

Toxicity assessment of concurrent gabapentin/pregabalin administration with high-dose melphalan in autologous hematopoietic cell transplant recipients.

A theoretical pharmacokinetic interaction mediated through L-amino acid transporter 1 and 2 exists between gabapentin (GP) and pregabalin (PG) with melphalan. Peripheral neuropathy is a common toxicity of various multiple myeloma regimens commonly utilized prior to autologous hematopoietic cell transplant (auto-HCT) with high-dose melphalan (HD-Mel). Therefore, it is likely concurrent administration of either GP or PG will occur in patients receiving HD-Mel conditioning for auto-HCT, which could potentially increase cellular uptake and worsen the mucosal injury. A retrospective chart review of adult patients from January 2012 to July 2016 who received HD-Mel (140-200 mg/m2) at West Virginia University Medicine was performed to assess toxicity and outcomes in these patients. A total of 80 patients were included in the study, with 30 patients receiving GP or PG and 50 control patients. There were no significant differences in grade 2 or higher mucositis, admissions for nausea/vomiting/diarrhea, intravenous opioid requirements, oral topical therapies, antidiarrheal medication use, rescue anti-emetics, days of nausea or vomiting, pain scores, neutrophil or platelet engraftment, treatment-related mortality, progression-free survival, or overall survival. Our data suggest that it is safe to continue GP/PG therapy throughout HD-Mel therapy, with no negative transplant outcomes. Prospective studies or evaluations of larger databases are necessary to better characterize the clinical effect of concomitant therapy.

Síndrome trófico trigeminal / Trigeminal trophic syndrome

El síndrome trófico trigeminal es una enfermedad infrecuente caracterizada por úlceras faciales autoprovocadas en regiones de anestesia o hipoestesia, secundarias al daño del nervio trigémino. Presentamos tres casos de este síndrome en seguimiento en nuestro centro.

Trigeminal trophic syndrome is an uncommon disease characterized by self-inflicted facial ulcers in anesthetic or hypoesthetic areas, secondary to trigeminal nerve damage. We present three cases in follow up at our hospital.

The combined analgesic effect of pregabalin and morphine in the treatment of pancreatic cancer pain, a retrospective study.

BACKGROUND: Pregabalin is commonly used to relieve neuropathic pain. However, data are lacking on its efficacy for the treatment of chronic cancer pain. The purpose of this study was to determine the analgesic efficacy of pregabalin combined with morphine in the management of pancreatic cancer pain. METHODS: This study reviewed patients who were prescribed morphine and 150 mg/d pregabalin between 1 January 2017 and 10 November 2018 in our institute. The primary outcomes of this study were the average pain score and dose of morphine. Secondary outcomes included characters of breakthrough cancer pain, functional interference related to pain, anxiety/depression status, and incidence of treatment-related adverse events during the study. RESULTS: A total of 240 patients with pain related to pancreatic cancer were included in the study. The results showed that patients of both combination therapy group (pregabalin+morphine) and monotherapy group (morphine) achieved similar analgesic efficacy, demonstrated by NRS (2.4 ± 0.9 vs. 2.6 ± 0.9; combination vs. monotherapy) at the end of the study. Mean daily dose of morphine used in the combination group was significant lower compared to monotherapy group (39.5 ± 16.0 mg vs. 61.5 ± 19.3 mg, net difference 23.5, 95% CI: 18.4-28.6, p < â€Š0.001). The change of functional interference score related to pain was significantly different between combination and monotherapy group (12.0 ± 0.4 vs. 9.8 ± 4.9; net difference, 2.3; 95% CI: 1.1-3.3; p < 0.001). Patients in combination therapy group had experienced shorter duration of breakthrough cancer pain than those in monotherapy group (X2 p < 0.001, Cramer's V:0.36). The incidence of somnolence, dizziness, and cognitive dysfunction were significantly higher in the combination group compared to monotherapy group. No serious treatment-related side effects were observed. CONCLUSIONS: The findings of this study supported the use of pregabalin with morphine to relieve pain in patients of pancreatic cancer.

Effects of pre-emptive pregabalin and multimodal anesthesia on postoperative opioid requirements in patients undergoing robot-assisted laparoscopic prostatectomy.

BACKGROUND: Previous findings indicate that pre-emptive pregabalin as part of multimodal anesthesia reduces opioid requirements compared to conventional anesthesia in patients undergoing robot-assisted laparoscopic prostatectomy (RALP). However, recent studies show contradictory evidence suggesting that pregabalin does not reduce postoperative pain or opioid consumption after surgeries. We conducted a register-based analysis on RALP patients treated over a 5-year period to evaluate postoperative opioid consumption between two multimodal anesthesia protocols. METHODS: We retrospectively evaluated patients undergoing RALP between years 2015 and 2019. Patients with American Society of Anesthesiologists status 1-3, age between 30 and 80 years and treated with standard multimodal anesthesia were included in the study. Pregabalin (PG) group received 150 mg of oral pregabalin as premedication before anesthesia induction, while the control (CTRL) group was treated conventionally. Postoperative opioid requirements were calculated as intravenous morphine equivalent doses for both groups. The impact of pregabalin on postoperative nausea and vomiting (PONV), and length of stay (LOS) was evaluated. RESULTS: We included 245 patients in the PG group and 103 in the CTRL group. Median (IQR) opioid consumption over 24 postoperative hours was 15 (8-24) and 17 (8-25) mg in PG and CTRL groups (p = 0.44). We found no difference in postoperative opioid requirement between the two groups in post anesthesia care unit, or within 12 h postoperatively (p = 0.16; p = 0.09). The length of post anesthesia care unit stay was same in each group and there was no difference in PONV Similarly, median postoperative LOS was 31 h in both groups. CONCLUSION: Patients undergoing RALP and receiving multimodal analgesia do not need significant amount of opioids postoperatively and can be discharged soon after the procedure. Pre-emptive administration of oral pregabalin does not reduce postoperative opioid consumption, PONV or LOS in these patients.

Pregabalin for neuropathic pain in primary care settings: recommendations for dosing and titration.

Pregabalin is one of the first-line treatments approved for the management of neuropathic pain (NeP). While many patients benefit from treatment with pregabalin, they are often treated with suboptimal doses, possibly due to unfamiliarity around prescribing the drug and/or side effects that can occur with up-titration. This narrative review discusses key aspects of initiating, titrating, and managing patients prescribed pregabalin therapy, and addresses concerns around driving and the potential for abuse, as well as when to seek specialist opinion. To ensure that patients derive maximum therapeutic benefit from the drug, we suggest a 'low and slow' dosing approach to limit common side effects and optimize tolerability alongside patients' expectations. When requiring titration to higher doses, we recommend initiating 'asymmetric dosing,' with the larger dose in the evening. Fully engaging patients in order for them to understand the expected timeline for efficacy and side effects (including their resolution), can also help determine the optimal titration tempo for each individual patient. The 'low and slow' approach also recognizes that patients with NeP are heterogeneous in terms of their optimal therapeutic dose of pregabalin. Hence, it is recommended that general practitioners closely monitor patients and up-titrate according to pain relief and side effects to limit suboptimal dosing or premature discontinuation.

Effects of dose titration on adherence and treatment duration of pregabalin among patients with neuropathic pain: A MarketScan database study.

OBJECTIVE: To examine pregabalin dose titration and its impact on treatment adherence and duration in patients with neuropathic pain (NeP). METHODS: MarketScan database (2009-2014) was used to extract a cohort of incident adult pregabalin users with NeP who had at least 12 months of follow-up data. Any dose augmentation within 45 days following the first pregabalin claim was defined as dose titration. Adherence (measured by medication possession ratio/MPR) and persistence (measured as the duration of continuous treatment) were compared between the cohorts with and without dose titration. Logistic regressions and Cox proportional hazards models were used to identify the factors associated with adherence (MPR ≥ 0.8) and predictors of time to discontinuation. RESULTS: Among the 5,186 patients in the analysis, only 18% of patients had dose titration. Patients who had dose titration were approximately 2.6 times as likely to be adherent (MPR ≥ 0.8) (odds ratio = 2.59, P < 0.001) than those who did not have dose titration. Kaplan-Meier analysis shows that the time to discontinuation or switch was significantly longer among patients who had dose titration (4.99 vs. 4.04 months, P = 0.009). CONCLUSIONS: Dose titration was associated with improved treatment adherence and persistence among NeP patients receiving pregabalin. The findings will provide valuable evidence to increase physician awareness of dose recommendations in the prescribing information and to educate patients on the importance of titration and adherence.

Is there any difference between oral preemptive pregabalin vs. placebo administration on response to EBUS-TBNA under sedation?

Background/aim: The aim of this study is to evaluate the effects of preemptive oral pregabalin on hemodynamic response, anxiety, sedation, and recovery in patients who underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) under sedation with intravenous ketamine-propofol combination. Materials and methods: Sixty patients were included in this study, and patients were randomly divided into two equal groups to receive the placebo (Group 1) versus pregabalin 150 mg (Group 2) one hour prior to EBUS- TBNA procedure. Patients received 0.25 mg kg-1 ketamine and 0.25 mg kg-1 propofol mixture (ketofol) for sedation. Timing of the parameters was defined as follows; T0: in hospital ward before pregabalin or placebo administration, T1: premedication, T2: in operating room, T3: before the procedure, T4: initiation, T5: 3 min after induction, T6: 6 min after induction, T7: 9 min after induction, and T8: 12 min after induction. Hemodynamic parameters, severity of coughing, sedation and anxiety scores, and complications were recorded. The level of satisfaction of the bronchoscopist and the patients were evaluated at the end of the procedure. Results: The heart rate and mean arterial pressure were significantly higher in Group 1 (P = 0.008, P = 0.04). Total doses of anesthetics, recovery time, and desaturation rate were significantly higher in Group 1 (P = 0.014, P = 0.001, P = 0.045). In Group 2, SpO2 level was significantly higher at various time periods (T1; P = 0.025, T4; P =0.043, T6; P = 0.001, T7; P = 0.003, T8; P < 0.001). The severity of coughing was found significantly lower in Group 2 (T4; P = 0.011, T5; P = 0.01, T6; P = 0.02, T7; P = 0.03, T8; P < 0.01). Anxiety scores were significantly lower in Group 2 (P < 0.001). Conclusion: Preemptive oral pregabalin, in addition to sedation with ketamine-propofol combination, was effective in providing limited hemodynamic response, restricted coughing reflex, and lower anxiety during EBUS-TBNA. Besides, with pregabalin usage, decreased anesthetics consumption, lower complication rate, and shorter recovery time might have contributed to safety of the procedure and comfort of the bronchoscopist.

Co-prescription of gabapentinoids and opioids among adults with and without osteoarthritis in the United Kingdom between 1995 and 2017.

OBJECTIVES: To produce national and regional estimates and trends for gabapentinoid-opioid co-prescribing rates in patients with OA, both in absolute terms and relative to matched controls without OA. METHODS: Using the UK Clinical Practice Research Datalink database we first constructed age-sex-practice-date 1:1 matched cohorts of patients aged ≥40 years with and without a new diagnosis of OA between 1995-2017 and estimated the relative incidence of a first gabapentinoid prescription. Incident gabapentinoid users in both cohorts were followed to estimate and compare the event rate of gabapentinoid-opioid co-prescription (prescription from both classes within the same 28-day window). RESULTS: The incidence of first gabapentinoid prescription was 3-fold higher in patients with OA than in matched controls [n = 215 357; incidence rate ratio (IRR) 2.93; 95% CI: 2.87, 3.00]. Among incident gabapentinoid users with OA (n = 27 374, median follow-up 3.9 years) the event rate of gabapentinoid-opioid co-prescription was 4.03 (4.02-4.05) per person-year. The rate was higher in OA patients classed as long-term gabapentinoid users (6.24; 6.22-6.26). These rates were significantly higher than in incident gabapentinoid users without OA [adjusted-IRR: 1.29 (1.28-1.30)]. This elevated risk was observed across age, sex, geographic regions, and calendar years, when restricted to strong opioids and to long-term gabapentinoid users, and when co-prescription was defined as within 14 days and same-day prescribing. CONCLUSIONS: Patients with OA not only have a higher risk of being prescribed a gabapentinoid but, once prescribed a gabapentinoid, are also at greater risk of opioid co-prescription. Strict restriction of gabapentinoid-opioid co-prescription, and improved access to, and uptake of, effective non-pharmacological and surgical alternatives for OA are required.

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.

Increasing the dosage of pregabalin in patients with focal epilepsy decreases the frequency of seizures and ameliorates symptoms of anxiety, depression and insomnia.

OBJECTIVE: The effectiveness of the treatment depends on the adequate dosage of medications. In clinical practice, drugs are often used at doses that are too low, which results in suboptimal levels of clinical improvement. The aim of the study was to evaluate the effects of increasing the dose of previously taken pregabalin in a group of patients with focal epilepsy and generalized anxiety disorder (GAD). PATIENTS AND METHODS: This open study involved 993 patients (46 ± 14 years old) suffering from epilepsy with focal seizures and concomitant GAD treated with pregabalin add-on therapy. The severity of anxiety was assessed with GAD-7 Scale. The number of epileptic seizures was monitored before and after the increase of the pregabalin dose. RESULTS: On the initial visit, the mean daily dose of pregabalin was 159 ± 82 mg. During the study period (nine months) the mean dose was increased to 327 ± 163 mg. After nine months, based on the intention-to-treat analysis, 27.1% (N = 253) of the subjects experienced seizure resolution, and 57.8% (N = 539) reduction in seizure frequency by at least 50%. At the beginning of the study, despite pregabalin administration, 60.7% of patients were above the diagnostic threshold for GAD diagnosis. The add-on therapy resulted in the improvement of the depressive and anxiety symptoms, and insomnia, greater in those that experienced seizure resolution or reduction in their frequency. CONCLUSIONS: (1) Patients with focal epilepsy with concomitant anxiety disorder experience reduction in seizure frequency, improvement of anxiety, depressive symptoms and insomnia using PGB as an add-on therapy. (2) Our data suggest that pregabalin as an add-on treatment is a reasonable choice for patients with focal epilepsy who have concomitant symptoms of an anxiety disorder.

Efficacy and Safety of the Controlled-release Pregabalin Tablet (GLA5PR GLARS-NF1) and Immediate-release Pregabalin Capsule for Peripheral Neuropathic Pain: A Multicenter, Randomized, Double-blind, Parallel-group, Active-controlled, Phase III Clinical Trial.

PURPOSE: This study compared the efficacy and safety of controlled-release pregabalin (GLA5PR GLARS-NF1 tablets) with those of an immediate-release pregabalin capsule after 12 weeks' administration to patients with peripheral neuropathic pain. METHODS: In this multicenter, randomized, double-blind, active-controlled, parallel-group, Phase III study, the primary outcome was to confirm that a single treatment with the study drug (after the evening meal) is clinically noninferior to the control drug (BID regimen) at improving the mean Daily Pain Rating Scale score for treating peripheral neuropathic pain. Secondary outcomes were the Daily Sleep Interference Scale, Medical Outcomes Study Sleep Scale, Hospital Anxiety and Depression scale, and frequency of rescue medication use. The safety and tolerability of GLA5PR GLARS-NF1 tablets were also evaluated. The total daily dose of pregabalin is 150-600 mg. FINDINGS: Of the 352 randomized subjects, 261 (n = 130, study group; n = 131, control group) were analyzed. The difference in adjusted mean Daily Pain Rating Scale scores between the groups was -0.11 (95% confidence interval, -0.05 to 0.30), indicating that the study group is noninferior to the control group. There was no statistically significant difference in Daily Sleep Interference Scale, Medical Outcomes Study Sleep Scale, and Hospital Anxiety and Depression scale scores between the groups at treatment termination. Logistic regression analysis revealed no significant difference in the use of rescue medication between the groups (P = 0.217). The overall adverse event profile of the groups was similar, and no serious adverse drug reactions were observed. IMPLICATIONS: GLA5PR GLARS-NF1 tablets can be effectively and safely administered to patients with peripheral neuropathic pain. Furthermore, we found that sleep, anxiety, and depression were improved with pain control. Owing to the once-daily administration, treatment effects can be maximized by improved treatment compliance. ClinicalTrials.gov identifier: NCT03221907.

Chronic Pregabalin Treatment Ameliorates Pain, but not Depressive-Like Behaviors, in a Reserpine-Induced Myalgia Model in Rats.

BACKGROUND: Anticonvulsants are often prescribed as coanalgesics for pathologies presenting chronic pain, such as chronic neuropathic pain and fibromyalgia. These pathologies are associated with a wide range of comorbidities: chronic fatigue, cognitive impairment, sleep disturbances, and mood disorders. Pregabalin, an anticonvulsant used to treat fibromyalgia syndrome, has been proven to improve pain and fatigue symptoms. However, most studies have not considered the analytic effect of this drug on comorbid depressive-like symptoms in this syndrome. OBJECTIVES: The main study objective was to examine the role of pregabalin in depressive symptomatology comorbid to chronic widespread pain using a reserpine-induced myalgia model. STUDY DESIGN: A randomized, controlled, animal study. SETTING: Research and data analyses were performed at the GESADA laboratory, Department of Human Anatomy and Embryology, University of Valencia, Spain. METHODS: Forty-six Sprague-Dawley male rats were used. Acute chronic pregabalin administration was tested for depressive-like behaviors (Forced Swimming and Novelty-Suppressed Feeding Tests) and for alteration of pain thresholds (tactile allodynia, Electronic Von Frey test; and mechanical hyperalgesia, Randall and Selitto test). The same procedures were followed with duloxetine as a positive control. RESULTS: Pregabalin significantly improved depressive-like behaviors in acute, but not chronic treatment, and significantly ameliorated pain thresholds. LIMITATIONS: Lack of histological and electrophysiological tests. CONCLUSIONS: Pregabalin is not effective in depressive-like symptoms associated with chronic pain but might play an acute antidepressive-like role given its antinociceptive effect.

Pregabalin administration and withdrawal affect testicular structure and functions in rats.

The aim of this prospective experimental study was to investigate the effects of pregabalin (PG) administration and withdrawal on testicular structures and functions in rats. A total of 24 male Wistar rats were divided into two groups (n = 12 each): a control group received normal saline, and PG-treated group received 62 mg kg-1  day-1 PG for 2 months. Half the animals of each group were sacrificed for the collection of blood and testicular samples. The remaining animals were bred for another 2 months without treatment before collection of blood and testicular samples. PG administration decreased testosterone and increased luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels versus controls. PG withdrawal led to a decrease in both FSH and LH and an increase in testosterone levels versus saline withdrawal. Compared to controls, PG administration caused degeneration of seminiferous tubules and decreased the number of spermatogenic but increased the number of Leydig cells. After PG withdrawal, these cells showed a rebound reverse. Reduced glutathione levels increased with PG administration while PG withdrawal increased malondialdehyde levels. Conclusion: PG administration affected testicular morphometry, gonadotrophic and sex hormones; however, there was a rebound reversal in all these parameters and a significant oxidative stress in PG withdrawal.

Co-administration of Pregabalin and Curcumin Synergistically Decreases Pain-Like Behaviors in Acute Nociceptive Pain Murine Models.

Analgesic drugs in a combination-form can achieve greater efficacy with lesser side effects compared to either drug alone. The combination of drugs acting at different targets or mechanisms of action has been recognized as an alternative approach for achieving optimal analgesia. In this study, the analgesic effects of pregabalin (30, 60, 100, 200 mg/kg), curcumin (15, 30, 60, 100, 120 mg/kg), and 1:1 fixed-dose ratio of the pregabalin-curcumin combination were assessed using two acute nociceptive pain models, the acetic acid-induced writhing and tail-flick tests in mice. The pregabalin-curcumin combination produced a dose-dependent decrease in mean of writhes and an increase in the percentage of antinociception by the acetic acid-induced writhing test. In the tail-flick test, the combination also showed an improvement in antinociception indicated by the tail-flick latency, % antinociception, and area under the curve (AUC). Isobolographic analysis of interactions demonstrated a significant synergistic interaction effect between pregabalin and curcumin in both acute nociceptive pain models with the experimental ED50 below the predicted additive line and the combination index < 1. These findings demonstrate that the combination of pregabalin and curcumin exhibits a synergistic interaction in mouse models of acute nociceptive pain.

The analgesic efficiency of pregabalin for the treatment of postoperative pain in total hip arthroplasty: A randomized controlled study protocol.

BACKGROUND: Only few studies have yet investigated whether perioperative administration of pregabalin can reduce the incidence of postoperative chronic neuropathic pain after total hip arthroplasty (THA). This prospective, randomized study compared placebo with pregabalin in the hope that a lower pregabalin dose would improve analgesia without increasing side-effects after THA. METHODS: This study was a prospective randomized blinded study, with a parallel design and an allocation ratio of 1:1 for the treatment groups. The study was approved by the Institutional Review Board in Weifang People's Hospital and written informed consent was obtained from all subjects before enrolment. A total of 120 patients who meet inclusion criteria are randomized to either pregabalin or placebo group. The primary objective of the study was visual analog scale score. As secondary outcomes, opioid consumption measurement, Harris Hip Score, hip range of motion, patient satisfaction, and complications were made at different time points throughout the study for comparison. RESULTS: The null hypothesis of this study was that pregabalin would reduce pain after THA. TRIAL REGISTRATION: This study protocol was registered in Research Registry (researchregistry5669).