Sodium oxybate for cataplexy

OBJECTIVE: To review the pharmacology, pharmacokinetics, clinical efficacy, adverse effects, drug interactions, precautions, dosing recommendations, and patient counseling of sodium oxybate for the treatment of cataplexy in patients with narcolepsy. DATA SOURCES: OVID and PubMed databases were searched (1966-January 2006) using the key words sodium oxybate, gamma-hydroxybutyrate, narcolepsy, and cataplexy. Only English-language articles were selected. STUDY SELECTION AND DATA EXTRACTION: All information on sodium oxybate related to narcolepsy and cataplexy was considered. Study selection included human trials evaluating safety and efficacy of sodium oxybate for the treatment of cataplexy. DATA SYNTHESIS: Sodium oxybate is approved by the Food and Drug Administration for the treatment of excessive daytime sleepiness and cataplexy in patients with narcolepsy. In placebo-controlled trials, sodium oxybate demonstrated efficacy in reducing the number of cataplexy attacks. The dosing regimen includes a split dose given at bedtime and 2.5-4 hours later due to its short elimination half-life. The drug is generally well tolerated, with headache, nausea, dizziness, pain, and somnolence being the most common adverse events. CONCLUSIONS: Sodium oxybate is safe and effective for the treatment of cataplexy. Potential disadvantages include a multiple dosing regimen, abuse potential, cost, and a closed distribution system. Potential advantages demonstrated in clinical trials include significant decreases in the number of weekly cataplexy attacks, improvement in daytime sleepiness, and improvement in the Clinical Global Impression of Change score and nighttime awakenings. Overall, sodium oxybate provides a new option for the treatment of cataplexy.     

GHB (gamma-hydroxybutyrate) carrier-mediated transport across the blood-brain barrier

gamma-Hydroxybutyrate (sodium oxybate, GHB) is an approved therapeutic agent for cataplexy with narcolepsy. GHB is widely abused as an anabolic agent, euphoriant, and date rape drug. Recreational abuse or overdose of GHB (or its precursors gamma-butyrolactone or 1,4-butanediol) results in dose-dependent central nervous system (CNS) effects (respiratory depression, unconsciousness, coma, and death) as well as tolerance and withdrawal. An understanding of the CNS transport mechanisms of GHB may provide insight into overdose treatment approaches. The hypothesis that GHB undergoes carrier-mediated transport across the BBB was tested using a rat in situ brain perfusion technique. Various pharmacological agents were used to probe the pharmacological characteristics of the transporter. GHB exhibited carrier-mediated transport across the BBB consistent with a high-capacity, low-affinity transporter; averaged brain region parameters were V(max) = 709 +/- 214 nmol/min/g, K(m) = 11.0 +/- 3.56 mM, and CL(ns) = 0.019 +/- 0.003 cm(3)/min/g. Short-chain monocarboxylic acids (pyruvic, lactic, and beta-hydroxybutyric), medium-chain fatty acids (hexanoic and valproic), and organic anions (probenecid, benzoic, salicylic, and alpha-cyano-4-hydroxycinnamic acid) significantly inhibited GHB influx by 35 to 90%. Dicarboxylic acids (succinic and glutaric) and gamma-aminobutyric acid did not inhibit GHB BBB transport. Mutual inhibition was observed between GHB and benzoic acid, a well known substrate of the monocarboxylate transporter MCT1. These results are suggestive of GHB crossing the BBB via an MCT isoform. These novel findings of GHB BBB transport suggest potential therapeutic approaches in the treatment of GHB overdoses. We are currently conducting "proof-of-concept" studies involving the use of GHB brain transport inhibitors during GHB toxicity.     

Sodium oxybate reduces pain, fatigue, and sleep disturbance and improves functionality in fibromyalgia: results from a 14-week, randomized, double-blind, placebo-controlled study

This 14-week, phase 3, double-blind, randomized, controlled trial evaluated sodium oxybate (SXB) 4.5 and 6g per night versus placebo in patients with fibromyalgia (FM). SXB is the sodium salt of γ-hydroxybutyrate (GHB). GHB is an endogenous compound, synthesized from γ-aminobutyric acid (GABA) and found broadly in the central nervous system and body. Among 548 randomized patients, a ≥30% reduction in pain was experienced by 54.2% and 58.5% of patients treated with SXB 4.5 and 6g, respectively, versus 35.2% for placebo with a 100-mm Visual Analog Scale (VAS) (P<0.001 for both comparisons). Relative to placebo, both SXB doses significantly reduced fatigue (with a 100-mm VAS; P<0.001) and sleep disturbance (with the Jenkins Sleep Scale; P<0.001), and resulted in significant improvements in function as measured by the FM Impact Questionnaire (P=0.003 and P=0.001 for 4.5 and 6 g per night, respectively). On the Short-Form 36 Health Survey, SXB-related improvement was significant on the Physical, but not the Mental, Component Scale. The proportion of patients who reported a global improvement of "much" or "very much" better on the Patient Global Impression of Change was significantly greater in both SXB groups versus placebo (P<0.001). Headache, nausea, dizziness, vomiting, diarrhea, anxiety, and sinusitis were the most commonly reported adverse events, with an incidence at least twice that of placebo. These results expand the evidence from previous clinical trials suggesting that SXB is effective and safe in FM.     

Gamma-hydroxybutyric Acid Tolerance and Withdrawal in a Rat Model

Long-term daily use of gamma-hydroxybutyrate (GHB) and related compounds has recently been associated with a withdrawal syndrome. To the best of the authors' knowledge, there are currently no animal models of GHB withdrawal. OBJECTIVES: The authors studied and described the effect of chronic dosing of GHB (3-6 days) on tolerance and withdrawal in a rat model. METHODS: Rats were administered GHB every three hours via intraperitoneal catheter. Groups of rats (2 per group) were dosed with GHB for either 3 (24 doses), 4 (32 doses), 5 (40 doses), or 6 (48 doses) days. The GHB dose was 0.25 g/kg for doses 1-8, 0.75 g/kg for doses 9-12, 1 g/kg for doses 13-16, 1.25 g/kg for doses 17-24, 1.5 g/kg for doses 25-32, 1.75 g/kg for doses 33-40, and 2 g/kg for doses 41-48. Following the last dose of GHB, the rats were scored using a 16-point ethanol intoxication-withdrawal scale rating spontaneous behaviors, response to handling, grooming, and neurological signs. Lower scores indicate intoxication, while higher scores indicate withdrawal. Scores were recorded at hours 0, 1, 2, 3, 4, 5, 6, 9, 12, and 24. RESULTS: Tolerance: Rats dosed with GHB for more days were less intoxicated one hour after their last GHB dose despite receiving higher doses. WITHDRAWAL: The scores for all rats dosed with GHB increased at hours 4 (p = 0.028), 5 (p = 0.037), 6 (p = 0.007), and 9 (p = 0.024) after the last dose, indicating withdrawal. The scores demonstrated a linear increase dependent upon the number of days of GHB dosing at hours 3 (p < 0.000), 4 (p = 0.004), 5 (p = 0.002), and 12 (p = 0.039) as well as prior to the last dose at hour 0 (p = 0.000). No rats developed seizures. CONCLUSIONS: Tolerance and mild withdrawal in rats can be induced by administering intraperitoneal GHB every three hours for 3-6 days. More prolonged dosing and higher doses of GHB may be necessary to induce severe withdrawal.     

A trial comparing nedocromil sodium (Tilade) and placebo in the management of bronchial asthma

In a double-blind group comparative trial nedocromil sodium (Tilade) at a dose of 4 mg four times daily was compared with placebo in the management of out-patients with bronchial asthma. Treatments were delivered by pressurized aerosol over a period of 28 days following a 2-week base-line during which patients continued on their usual therapy. Twenty-one patients entered the nedocromil sodium group and twenty entered the placebo group. All were using beclomethasone dipropionate aerosol as maintenance steroid therapy plus intermittent use of a bronchodilator taken by inhalation. The dose of steroid was reduced for all patients after 2 weeks of treatment and again for approximately half the patients after 3 weeks trial treatment. Patients in the nedocromil sodium treatment group improved in respect of Diary Card symptom scores and peak expiratory flow rate (PEFR), and in their requirements for inhaled bronchodilators. Patients in the placebo group were worse, particularly in respect of daytime asthma symptoms (P less than 0.01), bronchodilator use (P less than 0.05) and morning PEFR during the third week of trial treatment (P less than 0.05). More patients in the nedocromil sodium group than in the placebo group thought their treatment had been effective (P less than 0.05). Nedocromil was well tolerated. Despite the short duration of treatment imposed at this stage in the clinical evaluation of a new compound, our results were sufficiently encouraging to prompt further evaluation of nedocromil sodium over the longer period required (3-12 months) for the clinical assessment of a new treatment for chronic asthma.     

Severe gamma-hydroxybutyrate withdrawal: a case report and literature review

We report a case of gamma-hydroxybutyrate (GHB) withdrawal resulting in severe agitation, mental status changes, elevated blood pressure, and tachycardia hours after stopping chronic use of GHB. The patient admitted to substantial GHB abuse on a daily basis for 2.5 years. Previous attempts at cessation reportedly resulted in diaphoresis, tremors, and agitation. The patient's symptoms, negative polypharmacy history, and negative urine and blood toxicological analysis for alcohol, benzodiazepines, sedative-hypnotics, or other substances suggested the diagnosis of GHB withdrawal. Later analysis of a patient drug sample confirmed the presence of GHB. The patient required 507 mg of lorazepam and 120 mg of diazepam over 90 h to control agitation. This is one of the few reported cases of GHB withdrawal and one of the most severe. Given the increasing use of GHB, more cases of severe GHB withdrawal should be anticipated.     

Intentional Intrathecal Opioid Detoxification in 3 Patients: Characterization of the Intrathecal Opioid Withdrawal Syndrome

Objective: Intrathecal (IT) drug delivery systems for patients with chronic non‐malignant pain are intended to improve pain and quality of life and reduce side effects of systemic use. A subset of patients may have escalating pain, functional decline, and/or intolerable side effects even as IT opioid doses are increased. Discontinuation of IT medications may represent a viable treatment option but strategies to accomplish this are needed. Subjects and Interventions: Three patients with intrathecal drug delivery systems (IDDS), inadequate pain control, and declining functionality underwent abrupt IT opioid cessation. This was accomplished through a standardized protocol with symptom‐triggered administration of clonidine and buprenorphine, monitored using the clinical opiate withdrawal scale. Results: Symptoms of IT withdrawal were similar in all patients and included diuresis, agitation, hyperalgesia, mild diarrhea, yawning, and taste and smell aversion. Hypertension and tachycardia were effectively controlled by clonidine administration. Classic symptoms of withdrawal, such as piloerection, chills, severe diarrhea, nausea, vomiting, diaphoresis, myoclonus, and mydriasis, were not noted. At 2 to 3 months follow‐up, patients reported decreased, but ongoing pain, with improvements in functional capacity and quality of life. Conclusions: This preliminary work demonstrates the safety of abrupt IT opioid cessation utilizing standardized inpatient withdrawal protocols. To our knowledge, these are among the first reported cases of intentional, controlled IT opioid cessation without initiation of an opioid bridge: self‐reported pain scores, functional capacity, and quality of life improved. The IT opioid withdrawal syndrome is characterized based upon our observations and a review of the literature.     

Oxytrex Minimizes Physical Dependence While Providing Effective Analgesia: A Randomized Controlled Trial in Low Back Pain

Physical dependence or withdrawal is an expected effect of prolonged opioid therapy. Oxytrex (oxycodone + ultralow-dose naltrexone) is an investigational drug shown here to minimize physical dependence while providing strong analgesia with twice-daily dosing. In this 719-patient, double-blind, placebo- and active-controlled Phase III clinical trial in chronic low back pain, patients were randomized to receive placebo, oxycodone qid, or oxytrex qid or bid. Each oxytrex tablet contains 1 microg naltrexone; oxytrex bid and qid treatments provide 2 and 4 microg naltrexone/day, respectively. Following a washout, patients with pain >or=5 on a 0-10 scale were dose-escalated weekly from 10 up to 80 mg/day until reaching adequate pain relief (相似文献   

Treatment of the Narcoleptiform Sleep Disorder in Chronic Fatigue Syndrome and Fibromyalgia with Sodium Oxybate

This study investigates the response of the underlying sleep disorder associated with Chronic Fatigue Syndrome (CFS) and fibromyalgia (FM) to treatment. We retrospectively reviewed 118 cases clinically consistent with CFS or FM, treated in a neurology practice. Abnormal findings on sleep studies and associated human leukocyte antigen markers, and a clinical pattern suggestive of narcolepsy, are present in a high proportion of patients. When considered appropriate based on the clinical picture and test results, treatment with sodium oxybate was offered to these patients. Sixty percent of patients treated with oxybate experienced significant relief of pain, while 75% experienced significant relief of fatigue. We postulate that the response to oxybate in CFS and FM suggests a disturbance of sleep similar to narcolepsy. These findings support this novel approach to intervention and further research. The inability to distinguish CFS and FM by testing and response to treatment suggests that they may represent variations of the same disorder or may be closely related disorders.     

Withdrawal from gamma-hydroxybutyrate, 1,4-butanediol and gamma-butyrolactone: a case report and systematic review

1,4-butanediol (1,4-BD) is an industrial solvent that is metabolized to gamma-hydroxybutyrate (GHB), a gamma-aminobutyric acid agonist and central nervous system depressant. GHB and its analogues are popular drugs of abuse. Withdrawal from these agents is characterized by autonomic instability and altered mental status. We report a case of withdrawal from 1,4-BD lasting 6 days and complicated by new onset of seizures and rhabdomyolysis. In addition, we conducted a systematic review of the English literature pertaining to withdrawal from GHB, 1,4-BD and gamma-butyrolactone (GBL). Data collected from source articles included last use prior to symptom onset, clinical features on presentation, duration of symptoms and outcome. Twenty-seven studies with 57 episodes of withdrawal were included. Thirty-six cases (63%) involved GHB, 3 cases (5%) involved 1,4-BD and 18 (32%) involved GBL. The most common patient symptoms were tremor (67%), hallucinations (63%), tachycardia (63%) and insomnia (58%). Seizures and rhabdomyolysis each occurred in 7% of cases, but only 1 death occurred. Emergency physicians must consider withdrawal from these agents when patients present with clinical features suggestive of a sedative-hypnotic withdrawal syndrome.     

Novel gamma-hydroxybutyric acid (GHB) analogs share some, but not all, of the behavioral effects of GHB and GABAB receptor agonists

gamma-Hydroxybutyrate (GHB), a therapeutic for narcolepsy and a drug of abuse, has several mechanisms of action that involve GHB and GABA(B) receptors, metabolism to GABA, and modulation of dopaminergic signaling. The aim of these studies was to examine the role of GHB and GABA(B) receptors in the behavioral effects of GHB. Three approaches were used to synthesize GHB analogs that bind selectively to GHB receptors and are not metabolized to GABA-active compounds. Radioligand binding assays identified UMB86 (4-hydroxy-4-napthylbutanoic acid, sodium salt), UMB72 [4-(3-phenylpropyloxy)butyric acid, sodium salt], UMB73 (4-benzyloxybutyric acid, sodium salt), 2-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid (3-HPA), and 4-hydroxy-4-phenylbutyric acid as compounds that displace [(3)H]NCS-382 [5-[(3)H]-(2E)-(5-hydroxy-5,7,8,9-tetrahydro-6H-benzo[a][7] annulen-6-ylidene) ethanoic acid] from GHB receptors at concentrations that do not markedly affect [(3)H]GABA binding to GABA(B) receptors. In rats and pigeons, GHB discriminative stimulus effects were not mimicked or attenuated by UMB86, UMB72, or 3-HPA up to doses that decreased responding. In mice, GHB, GHB precursors (gamma-butyrolactone and 1,4-butanediol) and GABA(B) receptor agonists [SKF97541 [3-aminopropyl(methyl)phosphinic acid hydrochloride] and baclofen] dose-dependently produced hypolocomotion, catalepsy, ataxia, and loss of righting. The GABA(B) receptor antagonist CGP35348 (3-aminopropyl(diethoxymethyl)phosphinic acid) attenuated catalepsy and ataxia that was observed after GHB and GABA(B) receptor agonists SKF97541 and baclofen. UMB86, UMB72, UMB73, and 3-HPA, like GHB, produced hypolocomotion, ataxia, and loss of righting; however, catalepsy was never observed with these compounds, which is consistent with the cataleptic effects of GHB being mediated by GABA(B) receptors. Ataxia that was observed with UMB86, UMB72, UMB73, and 3-HPA was not antagonized by CGP35348, suggesting that ataxia induced by these analogs is not mediated by GABA(B) receptors and might involve GHB receptors.     

Amitriptyline treatment in chronic drug-induced headache: a double-blind comparative pilot study

OBJECTIVE: To assess the effects of amitriptyline and sudden analgesic withdrawal on headache frequency and quality of life in patients suffering from chronic daily headache related to analgesics abuse. METHODS: Seventeen nondepressed patients with chronic drug-induced headache were included in a 9-week, parallel-group, randomized, double-blind, placebo-controlled study. After abrupt analgesic withdrawal, amitriptyline or an active placebo (trihexyphenidyl) was started. The primary efficacy variable was headache frequency recorded on a headache diary in the last 4 weeks of each treatment. The secondary efficacy variable was quality of life (Nottingham Health Profile). RESULTS: Headache frequency decreased by 45% in the amitriptyline group and by 28% in the trihexyphenidyl group. Amitriptyline enhanced all the dimensions of quality of life and significantly improved emotional reaction and social isolation. CONCLUSION: This pilot study suggests a beneficial effect of amitriptyline on headache frequency and quality of life for patients with chronic drug-induced headache.     

A narrative review on the management of medication overuse headache: the steep road from experience to evidence

The management of medication overuse headache (MOH) is based essentially on the withdrawal of the overused drug(s). Drug withdrawal is performed according to widely differing protocols, both within and across countries; therefore, therapeutic recommendations for the acute phase of detoxification vary considerably among studies. Basically, the aims of MOH management are: (a) to withdraw the overused drug(s); (b) to alleviate withdrawal symptoms by means of a bridge therapy, which includes pharmacological and non-pharmacological support, designed to help the patient to tolerate the withdrawal process; (c) to prevent relapse. Today, there is extensive debate over the best strategies for achieving these goals and the different aspects of this debate are discussed in this review. The authors searched for the best available evidence relating to the following questions: should medication withdrawal be abrupt or gradual? Should patients receive replacement therapy? What are the most effective therapeutic programmes for controlling withdrawal symptoms? Should replacement therapy be administered routinely or as rescue therapy? Should preventive treatment be started before, during or after withdrawal? What are the most effective preventive treatments? Should patients be managed through inpatient or outpatient withdrawal programmes? What is the best approach to adopt in preventing relapses? Treatment of MOH is a difficult challenge, but may be very rewarding. Although there is still a lack of high-quality studies providing evidence-based answers to the many specific questions it raises, neurologists need to know that the combination of education with a rational use of selected therapeutic strategies may be beneficial to people with chronic headache and help to relieve their suffering.     

Gamma‐hydroxybutyrate dependence in a rural setting in Wales

The use of gamma‐hydroxybutyrate (GHB) in the UK has been mainly associated with the club scene in major cities. GHB dependence has previously been reported in the UK. We report on a case of GHB dependence presenting as lone use in a rural setting. A young male was admitted to hospital in Bangor, North Wales following an overdose of GHB. He was manufacturing GHB at home from readily available precursors. He was also using GHB in a dependent manner with ‘around the clock’ GHB dosing. GHB detoxification was undertaken in a medical setting but presented significant management problems. The patient rapidly became delirious with auditory and visual hallucinations, disorientation and severe agitation. We have reviewed the available literature on GHB dependence and withdrawal.     

Acceptance and Commitment Therapy for Prevention of Chronic Postsurgical Pain and Opioid Use in At-Risk Veterans: A Pilot Randomized Controlled Study

High levels of pain, significant anxiety, or depressive symptoms before surgery put patients at elevated risk for chronic pain and prolonged opioid use following surgery. The purpose of this preliminary study was to assess the efficacy of a 1-day Acceptance and Commitment Therapy (ACT) workshop in “at-risk” veterans for the prevention of chronic pain and opioid use following orthopedic surgery. In a randomized controlled trial, 88 at-risk veterans undergoing orthopedic surgery were assigned to treatment as usual (TAU; n?=?44) or TAU plus a 1-day ACT workshop (n?=?44). Pain levels and opioid use were assessed up to 3 months following surgery. Pain acceptance and values-based behavior were assessed at baseline and 3-month follow-up. Participants who completed the ACT workshop reached pain and opioid cessation sooner than those in TAU. Postoperative complications exhibited a moderating effect on these outcomes, such that the effects of ACT were greater in patients without complications. Increases in pain acceptance and values-based behavior, processes targeted in ACT, were related to better outcomes. These promising results merit further investigation in a larger clinical trial. Providing an intervention before surgery for at-risk veterans has the potential to change clinical practice from a focus on management of postoperative pain to prevention of chronic pain in at-risk individuals.

Pharmacokinetics,bioavailability, and bioequivalence of lower‐sodium oxybate in healthy participants in two open‐label,randomized, crossover studies

American Academy of Sleep Medicine practice parameters designate sodium oxybate (SXB) as a standard of care for cataplexy, excessive daytime sleepiness (EDS), and disrupted night‐time sleep in narcolepsy. Recently, a lower‐sodium oxybate (LXB) with 92% less sodium than SXB was approved in the United States for the treatment of cataplexy or EDS in patients 7 years of age and older with narcolepsy. Two phase I, open‐label, randomized, single‐dose crossover pharmacokinetic studies in healthy adults were conducted. Single 4.5‐g oral doses of LXB and SXB were administered in a fasted or fed state. In the fasted state at equivalent oxybate doses, LXB, compared with SXB, had a lower maximum plasma concentration (C_max; study 1 [total aqueous volume, 240 ml]: 101.8 vs. 135.7 µg/ml; study 2 [60 ml]: 94.6 vs. 123.0 μg/ml), delayed time to C_max (T_max; study 1: 0.75 vs. 0.5 h; study 2: 1.0 vs. 0.5 h), but similar area under the curve (AUC; study 1: AUC_0‐t, 235.4 vs. 263.9 μg∙h/ml; AUC_0‐∞, 236.5 vs. 265.2 μg∙h/ml; study 2: AUC_0‐t, 241.5 vs. 254.7 μg∙h/ml; AUC_0‐∞, 243.1 vs. 256.3 μg∙h/ml). Bioequivalence criteria were met for AUC but not C_max (both studies). C_max and AUC were lower under fed than fasted conditions (LXB and SXB); differences between fed versus fasted were smaller for LXB than SXB. These pharmacokinetic differences between LXB and SXB are likely due to the lower sodium content in LXB. Pooled analyses demonstrated that a higher C_max is associated with a higher incidence of nausea and vomiting.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Sodium oxybate (SXB) and lower‐sodium oxybate (LXB) are approved in the United States for the treatment of cataplexy or excessive daytime sleepiness in patients greater than or equal to 7 years of age with narcolepsy. The pharmacokinetics (PK) of SXB includes a negative food effect (reduced maximum plasma concentration [C_max] and area under the curve [AUC]) and greater than dose‐proportional increase in exposure.

• WHAT QUESTION DID THIS STUDY ADDRESS?

What are the relative bioavailability and bioequivalence of LXB and SXB in the fasted state, and how is the PK of LXB affected by food?

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

At equivalent oxybate doses, in the fasted state, LXB had a lower C_max, delayed time to C_max, and similar AUC versus SXB (bioequivalence criteria met for AUC). C_max and AUC were lower under fed conditions (LXB and SXB); reduction in C_max with food was less for LXB compared with SXB. Lower oxybate C_max was associated with lower incidence of nausea and vomiting.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

PK differences between LXB and SXB may stem from reduced sodium. LXB represents a novel oxybate treatment for narcolepsy.     

Varenicline: A first-line treatment option for smoking cessation

Background: Varenicline acts as a partial agonist/antagonist with affinity and selectivity for α₄ β₂ nicotinic acetylcholine receptors. This activity at the nicotine-receptor level may help patients achieve smoking cessation by reducing cravings/withdrawal symptoms and smoking satisfaction.Objective: This article reviews the literature on the pharmacologic properties, therapeutic efficacy, and tolerability of varenicline for smoking cessation.Methods: Pertinent controlled clinical trials, meta-analyses, meeting abstracts, case reports, and review articles published in English between 1966 and May 2008 were identified through searches of MEDLINE and OVID using the terms varenicline, smoking, tobacco cessation, and CP 526555.Results: Eight clinical trials were identified that compared ≤12 weeks of varenicline treatment with placebo and/or bupropion sustained release (SR); one of the trials reported follow-up data to 24 weeks, and the remainder reported data to 52 weeks. During treatment with oral varenicline titrated to 1 mg BID, CO-confirmed 4-week continuous quit rates/continuous abstinence rates (CQRs/CARs) in weeks 9 through 12 ranged from 43.9% (odds ratio [OR] = 3.85 [95% CI, 2.69–5.50; P < 0.001 vs placebo]; OR = 1.90 [95% CI, 1.38–2.62; P < 0.001 vs bupropion SR]) to 65.4% (OR = 2.98 [95% CI, 1.78–4.99; P < 0.001 vs placebo]). In 4 of these trials, varenicline 1 mg BID was associated with significantly higher CQRs/CARs compared with placebo at week-52 follow-up, ranging from 21.9% (P < 0.001) to 34.6% (P = 0.036). One trial reported a significantly higher CAR at 52 weeks with varenicline compared with bupropion SR (23.0% vs 14.6%, respectively; P = 0.004), and another reported a significantly higher CAR at 52 weeks with varenicline compared with nicotine replacement therapy (25.9% vs 19.8%, respectively; P = 0.040). In a relapse-prevention study that included a 12-week extension period for participants who were abstinent after the initial 12 weeks of treatment, CARs were significantly improved at 24 weeks with varenicline relative to placebo (70.5% vs 49.6%, respectively; OR = 2.48; 95% CI, 1.95–3.16; P < 0.001). Treatment with varenicline was generally well tolerated in study populations with no major comorbidities. In a pooled analysis of 2 Phase III trials, the most commonly reported adverse events (AEs) with varenicline, bupropion SR, and placebo were nausea (28.8%, 9.9%, and 9.1%, respectively), insomnia (14.2%, 21.5%, and 12.6%), and headache (14.2%, 11.1%, and 12.4%). In a pooled analysis of 2 identically designed Phase III trials, bupropion SR was associated with the highest overall rates of discontinuation due to all-cause AEs compared with varenicline and placebo (13.9%, 9.5%, and 8.2%, respectively) and due to AEs considered related to study drug (12.1%, 7.9%, and 6.4%). In double-blind clinical trials of varenicline, nausea was the most frequently reported AE (16.3%–41.9%). Varenicline treatment should begin 7 days before the proposed smoking quit date; dose titration is recommended to minimize dose-related nausea. Based on postmarketing reports of serious AEs in vareniclinetreated patients, caution is recommended when operating vehicles or heavy machinery. Patient education and monitoring for potential AEs are also recommended, particularly in patients with a history of psychiatric illness.Conclusions: Varenicline has a unique mechanism of action compared with other first-line options for smoking cessation. Available clinical-trial data support its use as an effective and generally well-tolerated therapy for smoking cessation in healthy adult smokers, although there is a need for further efficacy and safety evaluation in the general population, particularly those with comorbid conditions.     

Topiramate reduces headache days in chronic migraine: a randomized, double-blind, placebo-controlled study

The aim of this study was to evaluate the efficacy and tolerability of topiramate for the prevention of chronic migraine in a randomized, double-blind, placebo-controlled trial. Chronic migraine is a common form of disabling headache presenting in headache subspecialty practice. Preventive treatments are essential for chronic migraine management, although there are few or no controlled empirical trial data on their use in this patient population. Topiramate is approved for the prophylaxis of migraine headache in adults. Patients (18-65 years) who experienced chronic migraine (defined as > or =15 monthly migraine days) for > or =3 months prior to trial entry and had > or =12 migraine days during the 4-week (28-day) baseline phase were randomized to topiramate or placebo for a 16-week, double-blind trial. Topiramate was titrated (25 mg weekly) to a target dose of 100 mg/day, allowing dosing flexibility from 50 to 200 mg/day, according to patient need. Existing migraine preventive treatments, except for antiepileptic drugs, were continued throughout the trial. The primary efficacy measure was the change in number of migraine days from the 28-day baseline phase to the last 28 days of the double-blind phase in the intent-to-treat population, which consisted of all patients who received at least one dose of study medication and had one outcome assessment during the double-blind phase. Health-related quality of life was evaluated with the Migraine Specific Quality of Life Questionnaire (MSQ, Version 2.1), the Headache Impact Test (HIT-6) and the Migraine Disability Assessment (MIDAS) questionnaires, and tolerability was assessed by adverse event (AE) reports and early trial discontinuations. Eighty-two patients were screened. Thirty-two patients in the intent-to-treat population (mean age 46 years; 75% female) received topiramate (mean modal dose +/- SD = 100 +/- 17 mg/day) and 27 patients received placebo. Mean (+/-SD) baseline number of migraine days per 4 weeks was 15.5 +/- 4.6 in the topiramate group and 16.4 +/- 4.4 in the placebo group. Most patients (78%) met the definition for acute medication overuse at baseline. The mean duration of treatment was 100 and 92 days for topiramate- and placebo-treated patients, respectively. Study completion rates for topiramate- and placebo-treated patients were 75% and 52%, respectively. Topiramate significantly reduced the mean number of monthly migraine days (+/-SD) by 3.5 +/- 6.3, compared with placebo (-0.2 +/- 4.7, P < 0.05). No significant intergroup differences were found for MSQ and HIT-6. MIDAS showed improvement with the topiramate treatment group (P = 0.042 vs. placebo). Treatment emergent adverse events were reported by 75% of topiramate-treated patients (37%, placebo). The most common AEs, paraesthesia, nausea, dizziness, dyspepsia, fatigue, anorexia and disturbance in attention, were reported by 53%, 9%, 6%, 6%, 6%, 6% and 6% of topiramate-treated patients, respectively, vs. 7%, 0%, 0%, 0%, 0%, 4% and 4% of placebo-treated patients. This randomized, double-blind, placebo-controlled trial demonstrates that topiramate is effective and reasonably well tolerated when used for the preventive treatment of chronic migraine, even in the presence of medication overuse.     

Cannabis use,dependence and withdrawal in indigenous male inmates

Background: No studies have investigated cannabis withdrawal in indigenous or incarcerated populations, and there is currently no standard treatment for cannabis withdrawal in Australian prisons.

Aims: This cross sectional survey examines cannabis use, dependence and involuntary (abrupt cessation) withdrawal in incarcerated indigenous males for the purpose of improving clinical management.

Methods: 101 consenting inmates (18–40 years) from an Australian correction centre were interviewed. Demographic characteristics, lifetime cannabis use (LCU), severity of dependence, cannabis withdrawal symptoms, psychological well-being and alcohol use were measured and compared using univariate and multivariate analyses.

Results: Cannabis withdrawal symptoms were reported in 57% of current cannabis users compared with 16% of non-users (p?<?0.01), indicating detectable cannabis dependence and withdrawal in a unique indigenous inmate population. Multivariate analysis revealed statistically significant associations between LCU and cannabis dependence (OR?=?8.1; 95% CI: 2.2–29.1) when controlling for psychological well-being and alcohol consumption.

Conclusions: Upon admission to a correction centre, cannabis users should be assessed and monitored for physical and psychological symptoms of withdrawal.

Implications: Routine cannabis withdrawal monitoring will maximise staff and inmate safety. This improvement to policy will ensure appropriate risk management of staff and inmates.