Pregabalin: a new neuromodulator with broad therapeutic indications

Effect of preoperative pregabalin on postoperative pain relief in thyroidectomy patients: A prospective observational study

Background:

Effective management of postoperative pain leads to increased patient satisfaction, earlier mobilization, reduced hospital stay and costs. One of the methods used for management of postoperative pain is preemptive analgesia-blockade of afferent nerve fibers before a painful stimulus. It modifies peripheral and central nervous system processing of noxious stimuli and reduces postoperative opioid consumption. In this study, we sought to determine whether the preoperative use of pregabalin reduced postoperative pain and morphine consumption in thyroidectomy.

Materials and Methods:

The observation was conducted on patients undergoing thyroidectomy surgery in two groups of 30 each. Of the two groups, one received a single oral dose of pregabalin 1 h preoperatively. Both the group of patients undergoes anesthesia in a similar manner. Following surgery the efficacy of the preoperative dose of pregabalin is observed by measuring the total opioid consumption 6 h postoperatively and assessing verbal numeric pain scales.

Results:

The mean time to request of rescue analgesia in pregabalin group was 322.07 ± 69.106 min when compared to morphine group 256.33 ± 111.978 min (P < 0.05). The mean pain scores in the postoperative period were also significantly lower in patients receiving pregabalin.

Conclusion:

Single oral dose of pregabalin was effective in reducing acute postoperative pain in thyroidectomy patients. It prolongs the time to the request of rescue analgesia and also results in lower postoperative pain scores in the immediate postoperative period. However a statistically significant low opioid consumption could not be proved.

The effect of gabapentin on reducing pain after laparoscopic gastric bypass surgery in patients with morbid obesity: a randomized clinical trial

Background:

Pain after laparoscopic gastric bypass surgery (LGBP) is a major problem. Gabapentin is an anticonvulsant drug that can be effective in postoperative pain control.

Objectives:

This study examined the effect of preoperative administration of gabapentin on reducing pain after LGBP in patients with morbid obesity.

Patients and Methods:

This randomized clinical trial was performed in Hazrat Rasoul Akram Medical Center in Tehran. A total of 60 patients undergoing LGBP were randomly allocated into two groups; one group received 100 mg of oral gabapentin and the other group received placebo. Pain was evaluated at recovery time, and at the first, second, fourth and sixth hour of surgery by visual analog scale. The number and dose of opioid use after surgery and incidence of postoperative complications, such as nausea and vomiting, agitation, and headache, were also recorded.

Results:

The mean pain score in the group receiving gabapentin was significantly lower than the placebo group (P < 0.001). Indications and dose of opioid consumption between the two groups were not statistically significant. Incidence of nausea/vomiting (P = 0.028) as well as agitation (P = 0.037) was significantly lower in the gabapentin group.

Conclusions:

Administration of gabapentin before surgery can reduce pain after LGBP. Furthermore, it is not accompanied by significant short-term adverse effects.

Neuropsychiatric symptoms accompanying thrombocytopenia following pregabalin treatment for neuralgia: a case report

CASE DESCRIPTION

A 28-year-old female patient developed an increased temperature and neuropsychiatric symptoms after receiving 75 mg pregabalin therapy for neuralgia. She presented initially with pyrexia and dizziness, followed by disorganized speech within an acute confusional state. Her body temperature returned to normal after taking 60 mg loxoprofen sodium several hours later. However, the neuropsychiatric symptoms did not improve until the next morning. Routine blood tests showed decreased platelet counts (from 131 × 109/L to 85 × 109/L). The following day, a further dose of 75 mg pregabalin was administered because of its effective amelioration of the patient's neuralgia. One hour later, the same symptoms appeared as had previously including increased body temperature of 39.2 °C accompanied by a lower platelet count (73 × 109/L).

CONCLUSION

Clinicians should be alert to the serious neuropsychiatric symptoms and thrombocytopenia associated with the use of pregabalin. Routine blood tests may be necessary upon initiation of pregabalin treatment.

Factors predicting adverse events associated with pregabalin administered for neuropathic pain relief

BACKGROUND

Pregabalin administration is occasionally abandoned due to adverse events such as somnolence, dizziness, unsteadiness, weight gain and edema. However, the exact causes of these differences in adverse events associated with pregabalin have not been elucidated.

OBJECTIVE

To identify factors predicting adverse events associated with pregabalin administered for neuropathic pain.

METHODS

The present study was a retrospective analysis involving 208&nbsp;patients with neuropathic pain who had been treated with pregabalin in the pain clinic at the authors' hospital between July 2010 and September 2011. Variables were extracted from the clinical records for regression analysis of factors related to the occurrence of adverse events associated with pregabalin administration. Multivariate logistic regression analysis was used to examine the relationship between various predictive factors and the adverse events.

RESULTS

Predictive factors were: duration of therapy (OR 1.684&nbsp;[95%&nbsp;CI 1.179 to 2.406]; P=0.0042) for somnolence; nonsteroidal anti-inflammatory drugs (OR 0.132 [95% CI 0.030 to 0.578]; P=0.0072), age (OR 3.137 [95% CI 1.220 to 8.066]; P=0.0177) and maintenance dose (OR 0.437 [95% CI 0.217 to 0.880]; P=0.0205) for unsteadiness; serum creatinine (OR 6.439&nbsp;[95% CI 1.541 to 26.902]; P=0.0107) for body weight gain; and neurotropin (OR 8.538 [95% CI 1.159 to 62.901]; P=0.0353) and serum creatinine (OR 6.912 [95% CI 1.118 to 42.726]; P=0.0375) for edema.

CONCLUSIONS

The results of the present study indicate that care is warranted regarding long durations of therapy for somnolence, advanced age rather than dose-dependent adverse events for unsteadiness, elevated serum creatinine level for weight gain, and elevated serum creatinine level and combination use of neurotropin for edema. The safety of the combined use of pregabalin and nonsteroidal anti-inflammatory drugs were also suggested.

Pharmacotherapy of essential tremor

Essential tremor (ET) is a common movement disorder but its pathogenesis remains poorly understood. This has limited the development of effective pharmacotherapy. The current therapeutic armamentaria for ET represent the product of careful clinical observation rather than targeted molecular modeling. Here we review their pharmacokinetics, metabolism, dosing, and adverse effect profiles and propose a treatment algorithm. We also discuss the concept of medically refractory tremor, as therapeutic trials should be limited unless invasive therapy is contraindicated or not desired by patients.

Pregabalin for the management of neuropathic pain in spinal cord injury

SUMMARY Pregabalin is the only US FDA-approved drug to date for neuropathic pain in spinal cord injured patients. Pregabalin is a novel GABA analog whose primary mechanism of action involves binding at the α2-δ subunit of voltage-sensitive calcium channels. Efficacy is noted within the first several days of administration. Dosing is typically initiated at 150 mg/day in divided doses, but may be started at even lower doses. Dosing can be increased gradually to a recommended maximum of 600 mg per day in divided dosing. Adverse events include somnolence, dizziness and dry mouth, and typically manifest within the first 2 weeks of treatment. Pregabalin is generally safe to use in combination with other pain medications or antidepressants, but safety in pregnant patients has not been established.

Pregabalin for opioid-refractory pain in a patient with ankylosing spondylitis

Background. Ankylosing spondylitis (AS) is a systemic inflammatory disease with chronic back pain as the most common presenting symptom. We present a case of a male patient with AS reporting symptoms of severe low back pain, buttock pain, and limited spinal mobility. After chronic treatment with opioids, we administered pregabalin at a dose of 300 mg as an analgesic agent while opioids were discontinued. Findings. Pain symptoms improved progressively, and opioids were gradually discontinued without any withdrawal symptoms reported. Conclusions. Pregabalin is potentially useful in the management of pain in patients with AS while effectively managing the discontinuation of opioid treatment.

Understanding the pharmacokinetics of anxiolytic drugs

INTRODUCTION

Anxiety disorders are considered the most common mental disorders and they can increase the risk for comorbid mood and substance use disorders, significantly contributing to the global burden of disease. For this reason, anxiolytics are the most prescribed psychoactive drugs, particularly in the Western world.

AREAS COVERED

This review aims to analyze pharmacokinetic profile, plasma level variations so as the metabolism, interactions and possible relation to clinical effect of several drugs which are used primarily as anxiolytics. The drugs analyzed include benzodiazepines, anticonvulsants (pregabalin, gabapentin), buspirone, β-blockers and antihistamines (hydroxyzine). Regarding the most frequently used anxiolytic benzodiazepines, data on alprazolam, bromazepam, chlordesmethyldiazepam, chlordiazepoxide, clotiazepam, diazepam, etizolam, lorazepam, oxazepam, prazepam and clonazepam have been detailed.

EXPERT OPINION

There is a need for a more balanced assessment of the benefits and risks associated with benzodiazepine use, particularly considering pharmacokinetic profile of the drugs to ensure that patients, who would truly benefit from these agents, are not denied appropriate treatment. An optimal pharmacological approach involving an integrative pharmacokinetic and pharmacodynamic optimization strategy would ensure better treatment and personalization of anxiety disorders. So it would be desirable for the development of new anxiolytic drug(s) that are more selective, fast acting and free from the unwanted effects associated with the traditional benzodiazepines as tolerance or dependence.

A comparative bioavailability study of two formulations of pregabalin in healthy Chilean volunteers

OBJECTIVE

The aim of this study was to compare the pharmacokinetic parameters between two brands of pregabalin in healthy Chilean volunteers.

METHODS

A randomized, single-dose, two-period, two-sequence, crossover study design with a 2-week washout period was conducted in healthy Chilean males. Plasma samples were collected over a 12-hour period after administration of 150 mg pregabalin in each period. A validated ultra-performance liquid chromatography with positive ionization mass spectrometric detection method was used to analyze pregabalin concentration in plasma. Pharmacokinetic parameters were determined using a noncompartmental method. Bioequivalence between the test and reference products was determined when the ratio for the 90% confidence intervals (CIs) of the difference in the means of the log-transformed area under the curve (AUC)(0-t), AUC(0-∞), and maximum concentration (C(max)) of the two products were within 0.80 and 1.25.

RESULTS

The study was carried out on 22 healthy Chilean volunteers. The mean (SD) C(max), AUC(0-t) and AUC(0-∞) of the test formulation (Pregobin™) of pregabalin were 2.10 (0.56) μg/ml, 10.35 (2.00) μgxh/ml and 13.92 (2.74) μgxh/ml, respectively. The mean (SD) C(max), AUC(0-t) and AUC(0-∞) of the reference formulation (Lyrica™) of pregabalin were 2.15 (0.52) μg/ml, 10.31 (1.85) μgxh/ml and 13.78 (2.25) μgxh/ml, respectively. The parametric 90% CIs for C(max), AUC(0-t), and AUC(0-∞) were 0.97-1.13, 1.01-1.04, and 0.98-1.02, respectively.

CONCLUSIONS

These results suggest that both products are bioequivalent and can be used as interchangeable options in the clinical setting.

Effects of single-dose pregabalin on postoperative pain in dacryocystorhinostomy surgery

Background

Postoperative pain of dacryocystorhinostomy (DCA) surgery is one of the serious issues to be considered. Administrating opioids to relieve postoperative pain and facing their increasing side effects in eye surgeries, make the use of non-opioid drugs inevitable.

Objectives

The present study examined the efficacy of pregabalin in alleviating the postoperative pain of DCA surgery.

Patients and Methods

The present study has been carried out as a double-blind, randomized clinical trial on the patient candidates for DCR. The patients were randomly divided in to two groups of pregabalin and placebo. Patients in pregabalin group received 300 mg of pregabalin, an hour before the operation in the morning of the surgery. Pain intensity on visual analog scale (VAS) was recorded until 24 hours after the operation; also the rate of administrated opioids and nausea/vomiting frequency were recorded during the first 24-hour period after the operation and the resultsof the two groups were compared.

Results

Postoperative pain intensity in the pregabalin group at the time of recovery was significantly lower than that of the placebo group (P = 0.001) until 24 hours after the surgery. In the pregabalin group 17.5% of the patients received opioids while in the placebo group the figure was 52.5% (P = 0.001). Nausea frequency was also higher in the placebo group than the pregabalin group (P = 0.003).

Conclusions

A single 300 mg dose of pregabalin, an hour before DCA can effectively reduce pain intensity and also reduce opioid dose and nausea/vomiting.

Effect of oral pregabalin premedication on post-operative pain in laparoscopic gastric bypass surgery

Background

Post-operative pain and the administration of opioids to relieve it, is considered to be one of the important issues in surgery wards. This issue is even more significant in obese patients, because of the side effects of opioids. Pregabalin is an analog of gamma aminobutyric acid (GABA) which can be effective in dealing with post-operative pain.

Objectives

This study will consider the effect of oral pregabalin in relieving the pain of obese patients after gastric bypass surgery.

Patients and Methods

In a double blind clinical trial, 60 candidates for laparoscopic gastric bypass surgery were enrolled in the study through convenience and non-random sequential sampling, into two groups; pregabalin group and control group. Inclusion criteria consisted of: morbid obesity with a body mass index (BMI) > 35, age 18–50, American Society of Anesthesiologists (ASA) status I or II, and willingness to take part in the study. Patients in the pregabalin group received 300 mg of oral pregabalin on the morning of the surgery. Post-operative pain was controlled by the patient-controlled intravenous analgesia (PCIA) method, an AutoMed infusion pump containing 20 mg of morphine and normal saline (total volume 100 cc) was administered to all patients after surgery. Patients’ level of pain were compared by considering their pain intensity on a visual analog scale (VAS), and the occurrence of nausea/vomiting from recovery, until 24 hours after surgery.

Results

A total of 60 patients were compared; 30 patients in each of the pregabalin and control groups. Both groups were similar in age and sex distribution. Mean pain intensity levels during the whole follow up were lower in the pregabalin group than in the control group, up to a maximum of 24 hours after the operation (P < 0.001). Incidence of nausea/vomiting was greater in the control group than in the pregabalin group (P < 0.001).

Conclusions

The findings of this study indicate that oral pregabalin (300 mg dose) can alleviate patients’ pain and nausea/vomiting and notably reduce adverse effects.

Efficacy and safety of pregabalin in the treatment of alcohol and benzodiazepine dependence

INTRODUCTION

Both alcohol and benzodiazepine dependence (AD, BD) are severe and chronic conditions with devastating physical and mental health effects. The relative scarcity and controversial evidential status of available pharmacological interventions for the treatment of patients' acute withdrawal syndrome and/or relapse prevention call for the clinical investigation of novel safe and efficacious agents.

AREAS COVERED

We review published studies of pregabalin as monotherapy in the treatment of AD and BD in more than 450 patients. Available evidence includes four RCTs, two in AD with active comparator drugs (naltrexone, tiapride, and lorazepam) and one placebo-controlled, and one placebo-controlled in BD. We also review other available studies on pregabalin's potential to reduce benzodiazepine consumption, its side effects, especially cognitive, as well as extant reports on its liability for abuse.

EXPERT OPINION

Available evidence suggests that monotherapy with pregabalin, within the dosage range of 150 - 600 mg/d, is a promising "novel" option for the safe and efficacious relapse prevention of both AD and BD. However, its efficacy as monotherapy in the acute treatment of AD withdrawal syndrome is still controversial. Clinicians should be cautious in prescribing pregabalin to patients with a history of multiple substance recreational use, and monitor its effects on cognition at dosages above 450 mg/d. Further, well-designed clinical research is still needed for the eventual consolidation of pregabalin's place in the treatment of AD and BD.

Proposed medications for taxane-induced myalgia and arthralgia (Review)

Taxanes inhibit the disassembly of microtubules, which are involved in mitosis and axoplasmatic transport, and may cause the degeneration of peripheral, mainly small, sensory nerves. Peripheral neurotoxicity is a dose-limiting side-effect of taxanes. Neuroprotective agents may aid in the reduction of neurotoxicity, thus allowing the intensification of cytostatic therapy in patients. An increasing number of medications for the prevention of taxane-induced arthralgia and myalgia are becoming available to oncology teams. The most widely studied medications include so-called analgesics such as Shakuyaku-kanzo-to (a herbal medicine), corticosteroids and antihistamines. Arthralgias and myalgias (muscle spasms, fasciculations and prolonged contractions) may be extremely distressing for patients. New anti-epileptic drugs, particularly gabapentin and pregabalin, have proven to be safe and effective in the treatment of taxane-induced neurotoxicity. The aim of this review was to examine the topical choices available for the protective management of taxane-induced neurotoxicity monitored in preliminary case studies and clinical trials. At present, there is no standard of care for the prevention of taxane-induced arthralgia and myalgia. In combination with taxane-based chemotherapeutic regimens, these medical agents may be crucial in the treatment of a variety of types of cancer.

Pregabalin for the Treatment of Generalized Anxiety Disorder

Objective:

To evaluate the efficacy and tolerability of pregabalin in the treatment of generalized anxiety disorder (GAD).

Data Sources:

A search of PubMed (1966-December 2011) and International Pharmaceutical Abstracts (1970-December 2011) was conducted using the MeSH and free-text terms pregabalin, anxiety disorders, and anxiety.

Study Selection and Data Extraction:

All English-language articles identified through the search were evaluated for inclusion. Only randomized controlled trials involving the use of pregabalin for the treatment of GAD were included in the review.

Data Synthesis:

Eight published trials were identified through the search strategy. Successful treatment of GAD with pregabalin versus placebo and active comparators has been reported in clinical trials. Pregabalin lowered total Hamilton Rating Scale for Anxiety scores within 1 week and was effective against both somatic and psychic subcomponents. In 1 controlled clinical trial, pregabalin was found to be effective in patients aged 65 years and older. Another trial demonstrated improved relapse rates when pregabalin, compared with placebo, was used for up to 6 months. The most commonly experienced adverse events were somnolence, dizziness, headache, and dry mouth.

Conclusions:

Available evidence suggests that pregabalin is effective and well tolerated in the treatment of GAD. As somnolence and dizziness are common adverse effects, caution should be used in elderly patients. Pregabalin rapidly relieves anxiety, a benefit that it may have over many other currently available therapeutic options besides benzodiazepines. While not a first-line therapy in GAD, pregabalin offers another treatment option in patients who do not respond to or who suffer intolerable adverse effects from other agents.

Evaluation of the neurological safety of epidurally-administered pregabalin in rats

Background

The primary site of action of pregabalin, i.e. the α-2-δ subunit of the voltage-dependent calcium channel, is located at the dorsal root ganglion and dorsal horn of the spinal cord. Therefore, the epidural administration of pregabalin could have advantages over oral administration. However, the possibility of its neurotoxicity should be excluded before any attempt at epidural administration. We evaluated the neuronal safety of epidurally-administered pregabalin by observing the sensory/motor changes and examining the histopathology of spinal cord in rats.

Methods

Sixty rats of 180-230 g were divided into three groups; 3 mg of pregabalin dissolved in 0.3 ml saline (group P, n = 20), 0.3 ml 40% alcohol (group A, n = 20), or 0.3 ml normal saline (group N, n = 20) was administered epidurally to the rats in each group. Pinch-toe test, motor function evaluation, and histopathologic examination of vacuolation, chromatolysis, meningeal inflammation, and neuritis were performed at the 1st, 3rd, 7th, and 21st day after each epidural administration.

Results

All rats enrolled in group P, like those in group N, showed neither sensory/motor dysfunction nor any histopathological abnormality over the 3-week observation period. In contrast, in group A, 80% of the rats showed abnormal response to the pinch-toe test and all rats showed decreased motor function during the entire evaluation period. In addition, all histopathologic findings of neurotoxicity were observed exclusively in group A.

Conclusions

The epidurally administered pregabalin (about 15 mg/kg) did not cause any neurotoxic evidence, in terms of both sensory/motor function evaluation and histopathological examination in rats.

Pregabalin-Induced Hepatotoxicity

OBJECTIVE:

To report a case of acute elevation of hepatic enzyme levels as a probable adverse reaction associated with pregabalin.

CASE SUMMARY:

A 59-year-old man with a history of mantle cell lymphoma developed neuropathic pain and was treated with pregabalin 25 mg daily. Fourteen days after beginning pregabalin therapy, he developed left ankle edema and elevation of liver enzyme levels. Peak values were aspartate transaminase 907 U/L, alanine transaminase 1582 U/L, and γ-glutamyltransferase 510 U/L. Pregabalin was discontinued and hepatic enzyme levels returned gradually (over 4 months) to baseline levels.

DISCUSSION:

Many medications are commonly associated with liver injury; few cases of pregabalin-associated hepatotoxicity have been documented. A MEDLINE search (1966-November 2010) revealed 2 reports of acute liver injury with the initiation of pregabalin. In our patient, with hemosiderosis after hematopoietic cell transplantation, pregabalin worsened the underlying liver injury. The low pregabalin dosage and the short time to elevation of liver enzyme levels suggest an idiosyncratic reaction. According to the Naranjo probability scale and the Council for International Organizations of Medical Sciences probability scale, this reaction was probably due to pregabalin.

CONCLUSIONS:

Prescribers should be alert to the possibility of idiosyncratic hepatotoxicity associated with pregabalin use.

Effective dose of peri-operative oral pregabalin as an adjunct to multimodal analgesic regimen in lumbar spinal fusion surgery

STUDY DESIGN

A prospective, randomized, controlled, and double-blind trial.

OBJECTIVE

To evaluate the effects of 2 different doses of perioperative pregabalin administration, twice on the day of surgery, on acute postoperative pain after spinal surgery.

SUMMARY OF BACKGROUND DATA

Besides its well-established role on neuropathic pain, pregabalin seems to be a promising adjunct to multimodal analgesic regimen following surgery. No comprehensive data exist regarding the optimal dosage of pregabalin on reducing postoperative pain and opioid consumption in spinal surgery.

METHODS

Patients were randomly assigned to 1 of 3 groups. The placebo group (n = 28) received placebo capsules 1 hour before the anesthetic induction and 12 hours after surgery. The pregabalin groups received pregabalin 75 mg (P75 group, n = 28) or 150 mg (P150 group, n = 28), respectively at the same points. Assessed variables were total amount of administered fentanyl-based intravenous patient-controlled analgesia, pain intensity, and the frequency of rescue analgesic administered during the first 48 hours after surgery, subdivided into the following 4 periods: on arrival of patient to the postanesthesia care unit, 1 to 6 hours, 6 to 24 hours, and 24 to 48 hours. RESULTS.: The amount of patient-controlled analgesia volume infused until 24 hours (P 5 0.025) and 48 hours (P 5 0.028) after surgery was significantly less in the P150 group compared with the control group. The frequency of additional anodynes administered until 6 hours (P 5 0.049) and 24 hours (P 5 0.045) after surgery was significantly less in the P150 group compared with the control group.

CONCLUSION

Perioperative administration of pregabalin 150 mg before and 12 hours after surgery, but not 75 mg, significantly reduced opioid consumption and the use of additional pain rescue for 48 hours after surgery without significant side effects in patients undergoing spinal fusion surgery.

Chronic pruritus in the absence of specific skin disease: an update on pathophysiology, diagnosis, and therapy

Chronic pruritus is a major and distressing symptom of many cutaneous and systemic diseases and can significantly impair the patient's quality of life. Pruritus perception is the final result of a complex network involving dedicated nerve pathways and brain areas, and an increasing number of peripheral and central mediators are thought to be involved. Itch is associated with most cutaneous disorders and, in these circumstances, its management overlaps with that of the skin disease. Itch can also occur without associated skin diseases or primary skin lesions, but only with nonspecific lesions secondary to rubbing or scratching. Chronic itch with no or minimal skin changes can be secondary to important diseases, such as neurologic disorders, chronic renal failure, cholestasis, systemic infections, malignancies, and endocrine disorders, and may also result from exposure to some drugs. The search for the cause of pruritus usually requires a meticulous step-by-step assessment involving careful history taking as well as clinical examination and laboratory investigations. Few evidence-based treatments for pruritus are available. Topical therapy, oral histamine H(1) receptor antagonists, and phototherapy with UV radiation can target pruritus elicitation in the skin, whereas antiepileptic drugs, opioid receptor antagonists, and antidepressants can block signal processing in the CNS.

Pregabalin suppresses calcium-mediated proteolysis and improves stroke outcome

Pregabalin, a Ca(2+) channel α(2)δ-subunit antagonist with analgesic and antiepileptic activity, reduced neuronal loss and improved functional outcome in a mouse model of focal ischemic stroke. Pregabalin administration (5-10mg/kg, i.p.) 30-90 min after transient middle cerebral artery occlusion/reperfusion reduced infarct volume, neuronal death in the ischemic penumbra and neurological deficits at 24h post-stroke. Pregabalin significantly decreased the amount of Ca(2+)/calpain-mediated α-spectrin proteolysis in the cerebral cortex measured at 6h post-stroke. Together with the extensive clinical experience with pregabalin for other neurological indications, our findings suggest the potential for a therapeutic benefit of pregabalin in stroke patients.

Use of low-dose pregabalin in patients undergoing laparoscopic cholecystectomy

BACKGROUND

The objective of this study was to examine the effects of low-dose pregabalin on the analgesic efficacy, side-effects, and recovery profile in patients undergoing laparoscopic cholecystectomy.

METHODS

One hundred and sixty-two patients aged 18-65 yr, of ASA physical status I-III, undergoing elective outpatient laparoscopic cholecystectomy were recruited and randomized in this prospective, placebo-controlled, double-blind study to receive one of the following study medications orally: pregabalin 50 mg, pregabalin 75 mg, or placebo, 1 h before surgery and then every 12 h after operation for a total of three doses. Postoperative numeric pain scores, analgesic consumption, recovery score (QoR-40), and side-effects (opioid-related symptom distress scale) were assessed in the early postoperative period (every 15 min during the first hour, at 90, 120 min, 6, and 12 h) and at days 1, 2, and 7. Data were analysed using an intention-to-treat method.

RESULTS

Compared with the placebo group, the pain scores were lower in the pregabalin 75 mg group in the first 90 min after surgery (P<0.05). Pregabalin 50 mg resulted in pain reduction at 30 and 45 min (P<0.05) relative to placebo. The analgesic consumption, side-effects, and recovery scores were similar among the three groups.

CONCLUSIONS

Perioperative administration of pregabalin 75 mg provided limited analgesic benefit in the postoperative period. An updated meta-analysis confirms this finding (see Supplementary material).

Pregabalin in the treatment of alcohol and benzodiazepines dependence

We review all available studies on the use of the newer anticonvulsant drug pregabalin (PGB) in the treatment of both alcohol dependence (AD) and benzodiazepine dependence (BD). In AD, the available evidence includes one open-label and one double-blind randomized studies, whereas in BD, only a few case reports and one open-label study are as yet available. In both conditions, PGB was found efficacious with significant improvement in withdrawal symptoms at the dosage ranges of 150-450 mg/day (AD) and 225-900 mg/day (BD). Moreover, its side effects were mild and transient. Despite the limited quality of the studies design, their findings suggest that PGB might constitute a novel efficacious and safe option in the treatment of both AD and BD.

Pregabalin for the management of partial epilepsy

Pregabalin is one of the latest antiepileptic drugs introduced for the treatment of partial epilepsy. Its efficacy and safety as adjunctive therapy in refractory partial epilepsy have been established in four double-blind placebo-controlled trials (n = 1396) and 4 long-term open-label studies (n = 1480). In 3 fixed-dose trials, the proportion of patients with a >/=50% reduction in seizure frequency across the effective dose-range (150-600 mg/day) ranged between 14% and 51%, with a clear dose-response relationship. Suppression of seizure activity could be demonstrated as early as day 2. The most frequently reported CNS-related adverse events included dizziness, somnolence, ataxia and fatigue, were usually mild or moderate, and tended to be dose related. In long-term studies, weight gain was reported as an adverse event by 24% of patients. When pregabalin dose was individualized to according to response within the 150 to 600 mg/day dose range, tolerability was considerably improved compared with use of a high-dose, fixed-dose regimen (600 mg/day) without titration. In long-term studies up to 4 years, no evidence of loss efficacy was identified. During the last year on pregabalin, 3.7% of patients were seizure-free. Pregabalin appears to be a useful addition to the therapeutic armamentariun for the management of refractory partial epilepsy.

Pregabalin for neuropathic pain based on recent clinical trials

Pregabalin is a ligand for the alpha-2-delta subunit of voltage-gated calcium channels with anticonvulsant, analgesic, and anxiolytic properties. It has predictable absorption across the gastrointestinal tract, is neither metabolized nor protein-bound, and has minimal drug-drug interactions. It is effective with two or three-times daily dosing in a dose range of 150 to 600 mg daily. Seven published prospective, randomized clinical trials in postherpetic neuralgia (PHN) and painful diabetic peripheral neuropathy (DPN) demonstrate pain relief, decreased sleep interference, and improvements in several secondary outcome measures. The 50% responder rates for PHN and DPN compare favorably with other first-line agents for neuropathic pain. Pregabalin is well tolerated in most patients with infrequent severe adverse effects. Pregabalin is an important addition to the treatment armamentarium for neuropathic pain.

Remission of migraine attacks in a patient with depression who is taking pregabalin

Antiepileptic drugs (AED) are increasingly used in the treatment of migraine. Pregabalin (PGB) is an AED that has been used in the treatment of partial seizures, of various types of pain, and of certain anxiety disorders, but to the best of our knowledge, there has been no report on the use of PGB in the treatment of migraine. We report the case of a 60-year-old female inpatient with depression, long experiencing migraine, whose migraine symptoms improved markedly after receiving PGB in combination with escitalopram administered for her depression. The PGB mechanism of action in conjunction with its structural similarity with gabapentin, already successfully tested in the treatment of migraine, provide additional supportive evidence, theoretical and clinical, respectively, for PGB potential to alleviate migraine symptoms. However, only carefully randomized, controlled studies, or at the very least, open-label series of large patient samples treated in a similar fashion could establish the efficacy of PGB in migraine treatment.

[Treatment of neuropathic pain in HIV-infected patients]

Neuropathic pain of various etiologies is a frequent symptom in HIV-infected patients that is underdiagnosed and inadequately treated. It requires a multidisciplinary pain approach based on psychosocial factors, diet and exercise, etiologic treatment whenever possible, symptomatic medical treatment, and sometimes, interventional techniques. Medical treatment should be individualized and introduced gradually, with a mind to potential drug interactions. Neuropathic pain responds poorly to conventional analgesics, such as nonsteroidal antiinflammatory drugs and opiates; tricyclic antidepressants and anticonvulsants are the drugs of choice. Before establishing an analgesic treatment, possible drug interactions should be ruled out, mainly those occurring with antiretroviral agents.

Pregabalin in the discontinuation of long-term benzodiazepines' use

OBJECTIVE

Tolerance, dependence, and adverse effects on cognitive functions are well-known consequences of long-term use of benzodiazepines (BDZ), especially at high doses, raising thorny therapeutic problems in their discontinuation. One promising pharmacological agent in BDZ discontinuation might be the newer anti-epileptic pregabalin, already successfully tested in the treatment of anxiety disorders.

METHODS

We report on a sample of 15 patients with long-term, mostly high-dose dependence from BDZ, treated with pregabalin in an open-label study at doses 225-900 mg.

RESULTS

All patients discontinued successfully BDZ in 3-14 weeks, moreover with a significant reduction of their previous anxiety levels under BDZ. In addition, patients showed also a significant amelioration in their cognitive functioning. Pregabalin's side-effects were mild and transient, lasting only during the first 2 weeks of treatment.

CONCLUSION

Although preliminary, our findings suggest that pregabalin may be one new promising agent in the treatment of BDZ dependence.

Pregabalin as a neuroprotector after spinal cord injury in rats

The over-expression of excitotoxic neurotransmitter, such as glutamate, is an important mechanism of secondary injury after spinal cord injury. The authors examined the neuroprotective effect of pregabalin (GP) which is known as to reduce glutamate secretion, in a rat model of spinal cord injury. Thirty-two male Sprague-Dawley rats were randomly allocated to four groups; the control group (contusion injury only), the methylprednisolone treated group, the minocycline treated group and the GP treated group. Spinal cord injury was produced by contusion using the New York University impactor (25 g-cm, at the 9th-10th thoracic). Functional evaluations were done using the inclined plane test and a motor rating scale. Anti-apoptotic and anti-inflammatory effects were evaluated by in situ nick-end labeling staining technique (TUNEL) and immunofluorescence staining of cord tissues obtained at 7 days post-injury. Pregabalin treated animals showed significantly better functional recovery, and anti-apoptotic and anti-inflammatory effects. Mean numbers of TUNEL positive cells in the respective groups were 63.5 +/- 7.4, 53.6 +/- 4.0, 44.2 +/- 3.9 and 36.5 +/- 3.6. Double staining (TUNEL and anti-CC1) for oligodendrocyte apoptosis, was used to calculate oligodendrocyte apoptotic indexes (AI), using the following formula AI = (No. of doubly stained cells/No. of anti-CC1 positive cells) x 100. Mean group AIs were 88.6, 46.7, 82.1 and 70.3%, respectively. Mean numbers of activated microglia (anti-OX-42 positive cells) in high power fields were 29.8 +/- 3.9, 22.7 +/- 4.1, 21.0 +/- 3.9 and 17.8 +/- 4.3, respectively. This experiment demonstrates that GP can act as a neuroprotector after SCI in rats, and its anti-apoptotic and anti-inflammatory effects are related to its neuroprotective effect. Further studies are needed to unveil the specific mechanism involved at the receptor level.

Pregabalin in the discontinuation of long-term benzodiazepine use: a case-series

Tolerance, dependence, and adverse effects on cognitive functions are well known consequences of long-term use of benzodiazepines (BDZ), especially at high doses; this raises thorny therapeutic problems in their discontinuation. One promising pharmacological agent in BDZ discontinuation might be the newer antiepileptic, pregabalin (PGB), which has already successfully been tested in the treatment of anxiety disorders. We report on a series of four women with long-term, high-dose dependence on BDZ, who were treated with PGB at doses of 225-600 mg. All four patients discontinued BDZ successfully in 3-7 weeks. Moreover, they had an impressive reduction of their previous anxiety levels under BDZ. In addition, the patients showed a clinically significant amelioration in their cognitive functioning. The side effects of PGB were mild and transient, persisting only during the first 2 weeks of treatment. Although our findings are preliminary, they suggest that PGB might be one of the most promising of the newer agents in the treatment of BDZ dependence.

Pathophysiology and treatment of neuropathic pain associated with syringomyelia

The pain behaviour expressed by dogs with syringomyelia suggests that they experience neuropathic pain, probably due to disordered neural processing in the damaged dorsal horn. As such it is likely that conventional analgesic medication will be ineffective. In this review, physiological and pathological pain processing through the dorsal horn is summarised and mechanisms by which syringomyelia could result in a persistent pain state are discussed. Finally, current knowledge regarding treatment of Chiari malformation and syringomyelia is reviewed and possible drugs which may give improved pain relief in affected dogs are discussed.

Pregabalin in the management of central neuropathic pain

Central neuropathic pain is a painful condition, often severe, that occurs in a person who is already affected by an injury or disease of the brain or spinal cord. This dual insult is especially threatening to the quality of life of a person and their ability to perform even the most basic of tasks. Despite this high level of suffering there are relatively few trials investigating the management of central neuropathic pain. However, two randomised placebo-controlled studies have recently emerged demonstrating efficacy of pregabalin in reducing central neuropathic pain due to spinal cord injury and central poststroke pain. Pregabalin, an anticonvulsant, has been shown to be efficacious in the management of peripheral neuropathic pain of various causes and now may have a role to play in central neuropathic pain.

Palliative care in amyotrophic lateral sclerosis, Parkinson's disease, and multiple sclerosis

BACKGROUND

Amyotrophic lateral sclerosis, Parkinson's disease, atypical parkinsonian syndromes, and multiple sclerosis are progressive neurologic disorders that cumulatively afflict a large number of people. Effective end-of-life palliative care depends upon an understanding of the clinical aspects of each of these disorders.

OBJECTIVES

The authors review the unique and overlapping aspects of each of these disorders with an emphasis upon the clinical management of symptoms.

DESIGN

The authors review current management and the supporting literature.

CONCLUSIONS

Clinicians have many effective therapeutic options to choose from when managing the symptoms produced by these disorders.