Treatment of diabetic neuropathic pain with gabapentin alone or combined with vitamin B complex. preliminary results

Neuropathic pain is a syndrome that affects around 1% of population. This condition can be severely disabling and traditional analgesics are useless against this type of pain. Several adjuvants such as the anticonvulsive agent gabapentin have been used to treat diabetic neuropathy with several degrees of effectiveness, but it is characterized of a high incidence of dizziness, somnolence and ataxia. Previously we have found a functional synergistic interaction after co-administration of gabapentin and B vitamins by using a neuropathic pain model in the rat. In order to evaluate the efficacy of gabapentin and B vitamins in the treatment of diabetic neuropathy in humans we carried out a comparative trial. In this study are presented preliminary results from 6 patients assigned to two groups: group A (n=3) received gabapentin, and group B (n=3) received gabapentin plus B vitamins. In both groups, the dose was increased at weekly intervals, and characteristics of pain and some parameters of quality of life were assessed. Both treatments significantly reduced pain and improved quality of life in the patients. Dizziness was the main adverse event observed in both groups. Data suggest that the combination of gabapentin and B vitamins could be an alternative treatment for diabetic neuropathic patients.

A randomized, double-blind, placebo-controlled, phase III trial of pregabalin in the treatment of patients with fibromyalgia

OBJECTIVE

To evaluate the efficacy and safety of pregabalin for symptomatic relief of pain associated with fibromyalgia (FM) and for management of FM.

METHODS

This multicenter, double-blind, placebo-controlled trial randomly assigned 748 patients with FM to receive placebo or pregabalin 300, 450, or 600 mg/day (dosed twice daily) for 13 weeks. The primary outcome variable for study objective 1, symptomatic relief of pain associated with FM, was comparison of endpoint mean pain scores between each pregabalin group and placebo. The outcome variable for study objective 2, management of FM, included endpoint mean pain scores, Patient Global Impression of Change (PGIC), and Fibromyalgia Impact Questionnaire (FIQ)-Total Score. Secondary outcomes included assessments of sleep, fatigue, and mood disturbance.

RESULTS

Patients in all pregabalin groups showed statistically significant improvement in endpoint mean pain score and in PGIC response compared with placebo. Improvements in FIQ-Total Score for the pregabalin groups were numerically but not significantly greater than those for the placebo group. Compared with placebo, all pregabalin treatment groups showed statistically significant improvement in assessments of sleep and in patients' impressions of their global improvement. Dizziness and somnolence were the most frequently reported adverse events.

CONCLUSION

Pregabalin at 300, 450, and 600 mg/day was efficacious and safe for treatment of pain associated with FM. Pregabalin monotherapy provides clinically meaningful benefit to patients with FM.

Pregabalin in neuropathic pain: a more "pharmaceutically elegant" gabapentin?

OBJECTIVE

This article reviews the available information on pregabalin, a new anticonvulsant for peripheral neuropathic pain. Pregabalin was provisionally approved by the US Food and Drug Administration in December 2004 and was granted final approval after controlled substance scheduling (Schedule V) by the US Drug Enforcement Agency in August 2005.

METHODS

A MEDLINE search (1986-August 2005) was conducted to identify pertinent studies in the English language. The search terms included pregabalin, PD144723, CI-1008, gabapentin, and neuropathic pain. Additional references were obtained from the bibliographies of identified articles. All studies that evaluated any aspect of pregabalin in vitro or in vivo in animals or humans were included, with a focus on data relevant to older adults.

RESULTS

In preclinical studies, pregabalin, a structural congener of gabapentin, exhibited antinociceptive activity in animal models of neuropathic and inflammatory pain. Unlike gabapentin, pregabalin was well absorbed (> 90%), and its absorption was dose independent. Like gabapentin, pregabalin was predominantly excreted unchanged in the urine (> or = 98%). Dosed at 50 to 200 mg TID, pregabalin was superior to placebo in relieving pain and improving sleep and health-related quality of life in patients with diabetic peripheral neuropathy and postherpetic neuralgia (P < 0.001-P < 0.049). No active-controlled trials were available. The most problematic adverse events associated with pregabalin were dizziness and somnolence (21%-26%).

CONCLUSIONS

In the absence of active-controlled clinical trials and geriatric-specific efficacy/tolerability data, the place of pregabalin in the analgesic armamentarium for the elderly is unclear. Because pregabalin is a Schedule V controlled substance, its utility is not compromised by substantial limitation of access or the need for extra steps in prescribing. However, abuse potential is a consideration, and utilization should be carefully monitored, particularly in patients with a past or current history of substance abuse. The improved pharmacokinetic profile of pregabalin relative to gabapentin is manifested in linear and dose-independent absorption and a narrow therapeutic dosing range. However, pregabalin still requires multiple administrations per day, and daily doses > 150 mg/d require dose titration. The relatively high frequency of central nervous system adverse events, particularly dizziness and somnolence, is a concern in the elderly. Time and further experience should clarify the role of this agent.

[Preventive and cessation therapy of mental disorders in patients with the acute coronary syndrome]

An open prospective trial of 93 inpatients divided into two main groups (61 patients) - with mental disorders (31) and without mental disorders (30) and a comparison group (32 patients) was carried out. All patients survived the acute coronary syndrome (myocardial infarction, unstable angina). The efficacy and safety of both preventive and cessation therapy with pantogam active in mean doses 1.8 and 1.2 g /daily, respectively, was demonstrated in respect of heterogeneous depressive, anxiety and somatoform disorders of the neurotic level.

[Incomplete atrioventricular block in a patient on pregabalin therapy]

The authors report on a case of incomplete atrio-ventricular block in a patient on pregabalin therapy. Pregabalin was not overdosed; renal function of the patient was normal. The effect reverted after pregabalin discontinuation.

Because of γ-Aminobutyric Acid-Glutamate Imbalance, Gut Microbiota, or Both? Delirious Mania Induced by Ciprofloxacin Use: A Case Report and Review of the Literature

Ciprofloxacin is an antibiotic from the fluoroquinolone group that is frequently used in many clinical practices. In addition to its peripheral neuropathic side effects, it is an antibiotic that can pass through the blood-brain barrier due to its lipophilic features and cause rare central nervous system symptoms. Although cases of neuropsychiatric symptoms developing after treatment with ciprofloxacin have been reported in the literature, the number of reports of manic episodes after ciprofloxacin use is limited, and there have been no reports of delirious mania developing after ciprofloxacin use until the case presented in this report. Here we report the case of a 52-year-old woman who developed manic symptoms after receiving ciprofloxacin, which evolved into delirious mania. Clinical factors that may predispose to neurotoxicity are discussed and compared with features of the mania cases in the literature. The underlying neurobiological mechanisms are also reviewed.

[Iatrogenic diseases in the elderly]

The growing number of drugs used to treat various diseases and the growing number of invasive procedures used for diagnosis and therapy have generated many iatrogenic diseases. Elderly patients are more likely than the young to react adversely to drugs since the physiological functions of the organs, especially of the kidneys, decrease and pharmacokinetic characteristics altered. In addition, multiple disease states are common in the elderly, and multiple drugs are consequently prescribed. In the present study, adverse effects of so-called "cerebroactive drugs" and "cerebral vasodilators" are discussed. More than 30 kinds of these drugs are on the market in Japan and are widely prescribed for "chronic cerebrovascular diseases" and "dementia syndromes" in the elderly. In contrast, they are rarely used in Western Europe and not on the market in the United States. Among them, calcium hopantenate was the first of "cerebral activators" and was the most popular. In 1986, however, the first cases of toxic encephalopathy induced by calcium hopantenate were reported. It resembled Reye syndrome, showing coma, hepatic failure, lactic acidosis and hypoglycemia and was frequently fatal. More than 47 victims including 11 fatal cases have been reported since. Flunarizine, a cerebral vasodilator, produced high rates of parkinsonism and depression. Multicenter studies have revealed that these side effects occurred in 10-30% of the elderly patients who had taken it. These symptoms usually appeared several months after flunarizine was started. Some of the adverse effects of the drugs may be unpredictable and inevitable, but most of them can be prevented or reduced if physicians are more careful with their patients, and drugs and their adverse effects.2

[New drugs in the treatment of childhood epilepsy: vigabatrin (study of 61 subjects)]

This study was conducted to determine the efficacy of vigabatrin in children with epilepsy. Sixty-one children with various types of severe epilepsy were studied. In 12 children vigabatrin was introduced as monotherapy, while in 49 it was added to other antiepileptic drugs. Following the introduction of vigabatrin, 17 patients became seizure free, and 19 responded with a greater than 50% reduction in seizure frequency. The following types of epilepsy responded favorably to treatment (in order of decreasing efficacy): West syndrome, especially if secondary to Tuberous Sclerosis; cryptogenic and symptomatic partial epilepsy; Lennox-Gastaut syndrome, and other symptomatic generalized epilepsy. Optimal responses were found with vigabatrin doses of 30 to 50 mg/kg/day. Forty-one responders continued on vigabatrin, with generally good efficacy. Vigabatrin tolerability was good; in only 6 children was treatment discontinued because of side-effects such as somnolence, irritability, weight gain, and cutaneous rash. This study shows that vigabatrin is effective in the treatment of refractory epilepsy, especially in West syndrome secondary to Tuberous Sclerosis, partial epilepsy, and Lennox-Gastaut syndrome. Further studies are needed to analyze the increased frequency of seizures and the appearance of new seizure types associated with vigabatrin treatment.

[Neuropharmacology of a new model of partial epilepsy: GABA withdrawal syndrome]

In this work, we will describe the anatomical, behavioral, electrophysiological and neuropharmacological characteristics of a new model of focal epileptogenesis, the GABA-withdrawal syndrome (GWS). This particular model is original both because the manner in which is induced its electroclinical features, and because the physiopathological implications it represents. We will briefly describe the anticonvulsant effects of chronic, intracortical GABA infusions both in photosensitive baboons and in amygdala kindled rats, and show how the interruption of these infusions lead to the appearance of paroxysmal activity localized at the infusion sites. We will then describe more in detail this GWS, and show its dependency on GABA A receptor function. Furthermore, this GWS can be induced in hippocampal slices. Finally, we will propose the GWS as a useful model to study plastic phenomena in the brain and as a model of intractable epilepsy where screening of potential anticonvulsant agents will be feasible.

Focal lesion in the splenium of the corpus callosum in epileptic patients: antiepileptic drug toxicity?

BACKGROUND AND PURPOSE

Discrete focal lesions in the splenium of the corpus callosum on MR images in epileptic patients have received little attention in the literature. Our purpose was to describe these lesions, which may be related to the toxicity of antiepileptic drugs (AEDs), and to discuss the possible mechanisms of their development.

METHODS

We examined six patients with epilepsy whose brain MR imaging findings showed a discrete focal nonhemorrhagic lesion in the splenium of the corpus callosum. The medical records and MR images were reviewed retrospectively with respect to the patients' clinical history, medication, and laboratory findings to determine the etiology of the lesion.

RESULTS

In all six patients MR imaging showed a focal lesion in the splenium of the corpus callosum, which was ovoid in shape and 15 to 19 mm in size. In the three patients who received contrast material, there was no enhancement of the lesion. Four of six patients had a history of medication with dilantin, in two of whom the level of serum dilantin was found to be elevated (22.3 micrograms/mL and 70.4 micrograms/mL, respectively). Vigabatrin was administered in three patients, one of whom took dilantin together with vigabatrin. In two patients, the focal lesion in the corpus callosum disappeared on follow-up MR images after withdrawal of dilantin and/or vigabatrin.

CONCLUSION

A discrete, focal, ovoid, nonhemorrhagic lesion in the splenium of the corpus callosum may be seen on brain MR images of patients with epilepsy. The lesion is considered to be reversible demyelination related to AEDs toxicity.

Pregabalin: new drug. Very similar to gabapentin

(1) The first-line treatment for partial epilepsy is carbamazepine monotherapy; gabapentin monotherapy is an alternative, given its lower risk of drug-drug interactions. (2) The standard treatment for neuropathic pain associated with diabetes or post-herpetic neuralgia is a tricyclic antidepressant, with gabapentin as an alternative. Few drugs are available in this setting, and their efficacy is often modest. (3) Pregabalin is a GABA analogue closely related to gabapentin. Both drugs are marketed by Pfizer. Pregabalin has been approved for use in two indications: refractory partial epilepsy and neuropathic pain. (4) In patients with partial epilepsy inadequately controlled by a combination of two or possibly three antiepileptics, three placebo-controlled double-blind trials lasting 12 weeks suggest that adjunctive pregabalin treatment, at a dose of 600 mg/day divided in two or three doses, at least halves the frequency of seizures in 50% of patients. Pregabalin has not been compared with other second-line antiepileptics. (5) In neuropathic pain, there are 12 double-blind placebo-controlled trials involving patients with diabetes or post-herpetic neuralgia. Depending on the trial, between one-third and one-half of patients treated with pregabalin at a dose of 600 mg/day given in two or three doses had at least a 50% reduction in their pain score. In the only trial that included a group treated with amitriptyline (75 mg/day), the latter was significantly more effective than placebo, while pregabalin was not. (6) There are no comparative trials of pregabalin after amitriptyline and gabapentin failure. (7) The adverse effects profile of pregabalin is similar to that of gabapentin, and includes mainly neuropsychological reactions (dizziness and drowsiness). (8) Pregabalin, like gabapentin, can lead to weight gain and peripheral oedema especially in elderly patients. (9) Cases of visual field restriction have been reported with pregabalin in clinical trials. Animal studies suggest a possible risk of haemangiosarcoma, although no human cases have yet been described. (10) Pregabalin, like gabapentin, is eliminated unchanged in urine, implying a limited risk of interactions involving cytochrome P450, and suggesting that the dose should be reduced in patients with even moderate renal failure (creatinine clearance below 60 ml/min). (11) In practice, pregabalin offers nothing new for patients with partial epilepsy, for whom several other antiepileptics are available. The few available treatments for neuropathic pain have limited efficacy, and pregabalin may therefore be tried when both tricyclics and gabapentin fail. However, it is in no way certain that pregabalin is effective in such patients, and comparative trials are lacking.

[Neuropathic pain in oncology: mechanisms of its occurrence and current approaches to its treatment]

The paper provides evidence for the topicality of therapy for neuropathic pain syndrome (NPS) in cancer patients, describes the mechanisms of its occurrence, the specific features of its clinical manifestations, and presents a complex of currently available etiopathogenetic agents for the therapy of NPS. It also gives the authors' own data on the clinical application of the new anticonvulsant gabapentin (neurontin) in 34 patients with chronic NPS. The findings show the pronounced antineuropathic and analgesic effects of gabapentin in NPS. The side effects of the drug are not hazardous and they are moderately pronounced. These results are in agreement with the presented data of multicenter randomized placebo-controlled studies of the efficacy and tolerance of gabapentin in the treatment of cancer-induced NPS of various genesis.

Possible heart failure associated with pregabalin use: case report

Pregabalin and gabapentin are widely used analgesic, anticonvulsant and anxiolytic agents as they are relatively reliable and easily tolerated. However, they may cause some side effects such as dizziness, somnolence, dose-dependent peripheral edema, and weight gain, which may cause patients to abandon their use. Furthermore, there are a few reports in the literature addressing elderly patients with serious chronic disease and cardiac history, who develop heart failure during pregabalin application. In this report, we present a patient with no cardiac history treated with 300 mg/kg pregabalin due to neuropathic pain, who developed peripheral and then central edema, which were determined after advanced investigations. After stopping pregabalin, the situation regressed. Then, peripheral edema developed associated with the recommended dose of gabapentin, which was used in place of pregabalin. Despite the lack of any published evidence, the New York Heart Association issued a warning about using caution when prescribing pregabalin to type III-IV heart failure patients. Though the effect mechanisms of pregabalin and gabapentin are not well known, the calcium channel relationship may lead to these side effects. In summary, we believe that pregabalin and gabapentin, which is mostly used nowadays, should be administered with care not only in patients with advanced cardiac pathology but also in all patients, due to the potential side effects.

A case of pregabalin intoxication

Pregabalin, or S-(+)-3-isobutylgaba, is a lipophilic analogue of GABA. Although pregabalin is structurally related to GABA, it is inactive at GABA receptors and does not appear to mimic GABA physiologically. Pregabalin is a potent ligand for the alpha-2-delta subunit of voltage-gated calcium channels in the central nervous system. It is currently being licensed for epilepsy, neuropathic pain, and generalized anxiety disorder. There are few case reports that have demonstrated safety of pregabalin in case of intoxication. We report here a case of pregabalin toxicity with a moderate pregabalin concentration that was successfully managed with conservative treatment only. The case report describes a 54-year-old man who was treated with pregabalin for generalized anxiety disorder. After having experienced a significant stress on a job the patient ingested huge amount of pregabalin (4,2 r) together with bromazepam (21 mg) and chlorimipramine (125 mg). On presentation he was conscious and alert with a stable condition of cardiovascular and respiratory systems. The serum pregabalin concentration was 20.8 mg/L but the patient did not have any signs of toxicity. Thanks to his good and stable somatic condition the patient was managed with supportive treatment only. Although anecdotal, our case report points toward safety of pregabalin following deliberate self-poisoning. Our observation is in accordance with the recent international literature underlining that pregabalin was listed as the drug ingested in only 1% of fatalities, usually in combination with other drugs.

[Hepatotoxicity probably associated with gabapentin]

BACKGROUND

Gabapentin is an anticonvulsant medication used as an adjuvant in the treatment of neuropathic pain; few cases have been reported in which it causes acute liver injury.

CLINICAL CASE

56-year-old male patient with a history of chronic kidney disease on hemodialysis and narrowing of the spinal canal under treatment with gabapentin, who presented acute liver injury probably secondary to a dose of gabapentin; however, it remitted with the suspension of said drug.

CONCLUSION

Gabapentin lacks liver metabolism; the mechanism by which it produces liver injury is still unknown; however, there are reports of hepatotoxicity associated with its administration, so its use must be individualized for each patient.

[Metabolic acidosis and hypoglycemia during calcium hopantenate administration--report on 5 patients]

Calcium hopantenate (HOPA) has been widely used as an activator of cerebral metabolism in Japan. However, several cases of acute encephalopathy during HOPA administration were recently reported, which were characterized by marked metabolic acidosis and hypoglycemia. The encephalopathy in these patients was named Reye-like syndrome because of the similarity to Reye's syndrome in children. The purposes of this presentation are to report on 5 patients with acute encephalopathy developing during HOPA administration, to summarize their symptoms and clinical courses, and to discuss the pathogenesis of metabolic acidosis and hypoglycemia. Initial characteristics of the clinical course in all patients were loss of appetite, nausea and vomiting, followed by unconsciousness. Laboratory examinations revealed marked metabolic acidosis, severe hypoglycemia, hyperlactacidemia, leukocytosis, ketonuria, and increased Ht and BUN. A few days after development of the initial symptoms, mild renal and liver dysfunction, and elevation of serum amylase were observed in all patients. Hyperlactacidemia was present in 4 in the initial period. Blood concentration of HOPA was 2.131 micrograms/ml in patient 1 (8-10 hours after final administration), and 10.7 micrograms/ml in patient 5 (24 hours after final administration). These values are extremely high, because usually HOPA concentration is almost negligible 7 hours after the drug is taken. As the pathogenesis of acute encephalopathy due to HOPA administration, the failure of fatty acid beta-oxidation has been proposed by some investigators. However, the serum concentrations of CoA, pantothenic acid and carnitine during the initial stage were not reduced in our patients. Furthermore, it is very difficult to explain the severe hypoglycemia in terms of the beta-oxidation theory.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pregabalin--profile of efficacy and tolerability in neuropathic pain]

Pregabalin (PGB), like its predecessor gabapentin, is a structural analogue (but not functional) of the gammaaminobutyric acid (GABA). PGB has analgesic, antoconvulsivant, and ansiolytic activities. Neuropathic pain (NP) initial recommended dose is 150 mg per day. Depending on the patient response or bodily resistance to the drug the initial dose can be increased up to 300 mg per day (divided in 2-3 daily doses) during a one-week period. PGB is quickly absorbed in the digestive system with high oral biodisponibility. The drug is eliminated almost exclusively by renal excretion (98%). PGB efficacy was evaluated by several studies by means of visual analog scales (VAS) in several NP conditions such as post-herpetic neuropathy (PHN) or painful diabetic neuropathy (PDN). When compared with placebo, PGB provided significant benefit with 150 mg doses in the treatment of PHN pain. In studies developed in patients with PDN, the significant difference between placebo and treatment group only was achieved in individuals with daily doses of 300 mg/day, and the response was clearly dose-dependent. Tolerability information obtained from a number of studies has shown that the drug has a very good safety and tolerability profile. Side effects were mild to moderate and dose-dependent. Based on controlled studies, the main adverse effects observed with PGB are dizziness (23.1%), drowsiness (14.6%), and peripheral aedema (10.4%). As these side effects are dosedependent, they can be easily managed by a simple dose reduction, with no need to discontinue the therapy. Thus, according to efficacy and tolerability data, PGB is an important therapeutic option in NP treatment.

[Clinical experiences with pregabalin in the treatment of focal epilepsies]

INTRODUCTION

Pregabalin is an antiepileptic drug recently approved in the European Union for add-on therapy of focal epilepsy. A review of its clinical and pharmacological characteristics is, therefore, appropriate.

DEVELOPMENT

This drug, which binds to a subunit of voltage-dependent calcium channels in neuronal membranes, has a favourable pharmacokinetic profile. Pregabalin administered in two or three divided doses was compared to placebo in three double-blind randomised multicenter clinical trials, including 1,052 patients with focal epilepsy not controlled with other antiepileptic drugs. Results of these studies showed efficacy at doses of 150 mg per day, and a dose-response relationship up to doses of 600 mg per day. At the highest dose, mean seizure reduction for pregabalin was 44.3 to 54%, a significant reduction compared to placebo (p < or =0.0001), and a response rate of 43.5 to 51% (p < or =0.001). In one of these studies 12% of patients treated with pregabalin at 600 mg per day were seizure free for the last month of therapy while another study demonstrated its efficacy when used on a twice daily schedule. Subsequent open studies demonstrated a sustained efficacy of the drug. The most common adverse events were dizziness, somnolence, ataxia, asthenia, and weight gain. Withdrawal from controlled studies due to adverse effects was 15.3% in patients treated with pregabalin, compared with 6.15% in those receiving placebo.

CONCLUSION

Pregabalin favourable pharmacokinetic profile, in addition to its good tolerability and remarkable efficacy make this new antiepileptic drug an attractive option for the treatment of focal epilepsies.

[Efficacy and tolerability of dose-escalation with generic gabapentin--a multicenter, non-interventional study]

The aim of this study was to determine the efficacy and tolerability of 1800-2400 mg/day of generic gabapentin (Gabapentin Teva) as add-on treatment for refractory partial - onset epilepsy. This was a multicenter, open-label, dose-escalation study of patients with refractory epilepsy (median age of 45.5 years [41-50; 25-75% percentile range], male 45.6%, female 47.8%). The inclusion criteria were insufficient partial-onset epilepsy control, defined as at least 1 seizure per month, while on adjunctive therapy with gabapentin used on daily doses below 1200 mg. The baseline seizure number was assessed over 3 months of observation in patients being on stable doses of their AED therapy and those subjects who met the inclusion criteria were enrolled into the study by their neurologist (Visit 0). Subsequently, patients were seen, and their data were evaluated at Visit I i.e. after the target dose of 1800 mg per day was achieved (mean duration of 3.6 [0.1-28.3] weeks) and 4 weeks later at Visit II, after the target dose up to 2400 mg per day. Primary efficacy was assessed by seizure frequency (number/month). Tolerability was assessed by adverse events and clinical evaluations. All the study periods were completed by 916 patients. A substantially lower median seizure frequency was observed at all gabapentin dosing periods (visit I - 2.0 [0-40] seizures per month and visit II - 1.0 [0-13] seizures per month; median and range) compared with the baseline period (3.0 [1-20] seizures per month) (Wilcoxon test p<0.001). In addition, the gradual increase of GBP dose led to raising proportion of patients rendered seizure free (Visit I - 1.1% and Visit II - 28.5%) compared with the baseline period 0.0% (McNemar test p<0.001). The dose escalation with GBP was well tolerated by the majority of patients. The most common adverse events during visit II were somnolence (2.8%) and dizziness (1.8%). In conclusion, gabapentin dose escalation to a dose range of 1800-2400 mg/d over 8 [1-32] week period proved to be an effective and well tolerated in patients with insufficient seizure control on lower doses with partial-onset epilepsy.

Gabapentin encarbil (Horizant) for restless leg syndrome

Gabapentin enacarbil (Horizant-GlaxoSmithKline), a new extended-release (ER) tablet formulation of gabapentin, has been approved by the FDA for treatment of moderate-to-severe restless legs syndrome (RLS). The immediate-release (IR) formulation of gabapentin (Neurontin,and others), which is approved for treatment of epilepsy and postherpetic neuralgia, has been used for many years to treat RLS. Another ER tablet formulation of gabapentin (Gralise) has been approved by the FDA for treatment of postherpetic neuralgia.

Potential for pregabalin abuse or diversion after past drug-seeking behavior

Pregabalin, primarily used to manage neuropathic pain and fibromyalgia, is categorized as a Schedule V drug (ie, lowest potential for abuse) in the US Drug Enforcement Administration's Controlled Substances Act. Because pregabalin is not recognized as a drug with high-abuse potential, data on pregabalin abuse and addiction are lacking. The authors report a case of a 35-year-old woman with a history of opioid-seeking behavior who was prescribed pregabalin for pain control. The patient requested an increase in her medication 2 months after beginning treatment and, after her physician denied her request, subsequently obtained pregabalin from other sources. Over a 28-day period, the patient received a total of 88,500 mg of pregabalin. After learning of the other prescriptions, the patient's physician became suspicious of pregabalin abuse or diversion. In accordance with state medical board guidelines, the patient was discharged from the practice and referred to a local detoxification center.

Multimodal prevention of pain, nausea and vomiting after breast cancer surgery

BACKGROUND

Despite many one- or two-modal attempts to relieve postoperative nausea and vomiting (PONV) and pain, postoperative issues following breast cancer surgery remain a substantial problem. Therefore, the aim of this explorative, hypothesis-generating study was to evaluate the effect of a multimodal, opiate-sparing, evidence-based regimen for prevention of PONV and pain.

METHODS

Two hundred consecutive patients scheduled for breast cancer surgery were included. The prevention regimen included a package consisting of preoperative paracetamol, dextromethorphan, celecoxib, gabapentin, dexamethasone, total intravenous anaesthesia and intraoperative ondansetron. The patients were prospectively scored according to PONV, pain during rest and mobilization and major side effects.

RESULTS

Of 200 consecutive breast cancer patients, 191 received the full package. During the first 36 postoperative hours, 79.1% reported no PONV at all and only 3.7% reported severe PONV. At rest, 69.6% reported no or light pain and 3.1% reported severe pain, with corresponding values of 59.7% and 8.9% during arm mobilization. Mean postoperative morphine consumption was 2.2 mg. The only significant side effect was transient dizziness.

CONCLUSION

A multimodal, opiate-sparing regimen to prevent pain and PONV seems to be more effective than one- or two-component regimens on PONV and pain after breast cancer surgery, a result which calls for large-scale multi-center or randomized studies.