Phantom motor execution facilitated by machine learning and augmented reality as treatment for phantom limb pain: a single group, clinical trial in patients with chronic intractable phantom limb pain

BACKGROUND

Phantom limb pain is a debilitating condition for which no effective treatment has been found. We hypothesised that re-engagement of central and peripheral circuitry involved in motor execution could reduce phantom limb pain via competitive plasticity and reversal of cortical reorganisation.

METHODS

Patients with upper limb amputation and known chronic intractable phantom limb pain were recruited at three clinics in Sweden and one in Slovenia. Patients received 12 sessions of phantom motor execution using machine learning, augmented and virtual reality, and serious gaming. Changes in intensity, frequency, duration, quality, and intrusion of phantom limb pain were assessed by the use of the numeric rating scale, the pain rating index, the weighted pain distribution scale, and a study-specific frequency scale before each session and at follow-up interviews 1, 3, and 6 months after the last session. Changes in medication and prostheses were also monitored. Results are reported using descriptive statistics and analysed by non-parametric tests. The trial is registered at ClinicalTrials.gov, number NCT02281539.

FINDINGS

Between Sept 15, 2014, and April 10, 2015, 14 patients with intractable chronic phantom limb pain, for whom conventional treatments failed, were enrolled. After 12 sessions, patients showed statistically and clinically significant improvements in all metrics of phantom limb pain. Phantom limb pain decreased from pre-treatment to the last treatment session by 47% (SD 39; absolute mean change 1·0 [0·8]; p=0·001) for weighted pain distribution, 32% (38; absolute mean change 1·6 [1·8]; p=0·007) for the numeric rating scale, and 51% (33; absolute mean change 9·6 [8·1]; p=0·0001) for the pain rating index. The numeric rating scale score for intrusion of phantom limb pain in activities of daily living and sleep was reduced by 43% (SD 37; absolute mean change 2·4 [2·3]; p=0·004) and 61% (39; absolute mean change 2·3 [1·8]; p=0·001), respectively. Two of four patients who were on medication reduced their intake by 81% (absolute reduction 1300 mg, gabapentin) and 33% (absolute reduction 75 mg, pregabalin). Improvements remained 6 months after the last treatment.

INTERPRETATION

Our findings suggest potential value in motor execution of the phantom limb as a treatment for phantom limb pain. Promotion of phantom motor execution aided by machine learning, augmented and virtual reality, and gaming is a non-invasive, non-pharmacological, and engaging treatment with no identified side-effects at present.

FUNDING

Promobilia Foundation, VINNOVA, Jimmy Dahlstens Fond, PicoSolve, and Innovationskontor Väst.

Gabapentin misuse, abuse and diversion: a systematic review

BACKGROUND AND AIMS

Since its market release, gabapentin has been presumed to have no abuse potential and subsequently has been prescribed widely off-label, despite increasing reports of gabapentin misuse. This review estimates and describes the prevalence and effects of, motivations behind and risk factors for gabapentin misuse, abuse and diversion.

METHODS

Databases were searched for peer-reviewed papers demonstrating gabapentin misuse, characterized by taking a larger dosage than prescribed or taking gabapentin without a prescription, and diversion. All types of studies were considered; grey literature was excluded. Thirty-three papers met inclusion criteria, consisting of 23 case studies and 11 epidemiological reports. Published reports came from the United States, the United Kingdom, Germany, Finland, India, South Africa and France, and two analyzed websites not specific to a particular country.

RESULTS

Prevalence of gabapentin misuse in the general population was reported to be 1%, 40-65% among individuals with prescriptions and between 15 and 22% within populations of people who abuse opioids. An array of subjective experiences reminiscent of opioids, benzodiazepines and psychedelics were reported over a range of doses, including those within clinical recommendations. Gabapentin was misused primarily for recreational purposes, self-medication or intentional self-harm and was misused alone or in combination with other substances, especially opioids, benzodiazepines and/or alcohol. Individuals with histories of drug abuse were most often involved in its misuse.

CONCLUSIONS

Epidemiological and case report evidence suggests that the anti-epileptic and analgesic medication gabapentin is being misused internationally, with substance abuse populations at special risk for misuse/abuse.

[Treatment of pediatric epilepsy]

Recently, the treatment strategy for pediatric epilepsy has been dramatically changed in Japan, because of the approval of new-generation antiepileptic drugs. Since 2006, a total of 6 new antiepileptic drugs, including gabapentin (GBP; adults/pediatric patients: 2006/2011 [year of approval]), topiramate (TPM; 2007/2013), lamotrigine (LTG; 2008/2008), levetiracetam (LEV; 2010/2013), stiripentol (STP; 2012/2012), and rufinamide (RUF; 2013/2013), have been introduced. Thus far, valproate (VPA) and carbamazepine (CBZ) have been first indicated for "generalized" epilepsy and "focal" epilepsy syndromes/types, respectively, in Japan. However, the approval of these new drugs could allow us to choose more effective and less toxic ones at an early stage of treatment. In this chapter, we describe the latest domestic and foreign guidelines for the treatment of pediatric epilepsy.

[New antiepileptic drugs: characteristics and clinical applications]

New antiepileptic drugs (AEDs) that have been used in many other countries for more than 10 years have only recently became available for use in Japan. Gabapentin, topiramate, lamotrigine and levetiracetam were licensed for use in Japan between 2006 and 2010. Stiripentol for Dravet syndrome and rufinamide for Lennox-Gastaut syndrome were also approved in 2012 and 2013 as orphan drugs. Clinical trials of other new AEDs such as oxcarbazepine, vigabatrin, lacosamide, and perampanel are in progress. In this review, the general characteristics of the new AEDs are discussed with regards to their effectiveness, tolerability, drug interaction, safety and mechanisms of action. The effectiveness, of the new AEDs compared with established AEDs is also discussed. Clinical applications of the new AEDs, focusing on gabapentin, topiramate, lamotrigine and levetiracetam are also discussed based on our domestic experience as well as overseas reports.

[Lacosamide as an alternative in the treatment of post-surgery neuropathic pain in an allergic patient]

INTRODUCTION

Neuropathic pain is a condition that is still not well understood, although it affects a significantly high percentage of the population. The main problem lies in the fact that it can become a fairly disabling pathology. The most frequent treatment is based essentially on two drugs: gabapentin and pregabalin. Other pharmaceuticals, such as antidepressants, opioids or N-methyl-D-aspartate receptor antagonists can also be employed in combination with the primary drugs. All the same, treatment remains unsatisfactory. Furthermore, it must be borne in mind that there may be patients who are allergic to the two main drugs.

CASE REPORT

We report the case of a 36-year-old female with neuropathic pain secondary to surgery to correct a neurinoma in the brachial plexus, who could not be treated with gabapentin or pregabalin because of a personal history of allergy to these substances. Treatment with another drug (lacosamide), however, was very effective and displayed a very good response.

CONCLUSIONS

Lacosamide is a third-generation antiepileptic drug that has been proven to be effective, safe and with few side effects. It has been considered a good therapeutic option for the treatment of neuropathic pain in patients who are allergic to pregabalin.

Lack of Pharmacokinetic Interactions Between Cilomilast and Theophylline or Smoking in Healthy Volunteers

The pharmacokinetic profile of cilomilast (Ariflo), a selective phosphodiesterase 4 (PDE4) inhibitor, was investigated in three separate studies. Two of these studies explored the drug interaction potential of cilomilast with the nonselective PDE inhibitor, theophylline, and a third study compared the pharmacokinetic profile of cilomilast in smokers and nonsmokers. Repeated administration of cilomilast had no effect on the steady-state pharmacokinetics of theophylline in either a pilot dose-ranging or definitive therapeutic study. At therapeutic doses, the point estimate and 90% confidence interval for theophylline AUC(0-12) and C(max) were completely contained within the range (0.8, 1.25). Similarly, repeated administration of theophylline had little clinically relevant effect on the steady-state pharmacokinetics of cilomilast when compared to placebo, as only slight average increases in cilomilast AUC(0-12) and C(max) (6% and 3%, respectively) were observed. In addition, mean cilomilast exposure (AUC(0- infinity )) was found to be similar in both smokers and nonsmokers (8.47 +/- 2.20 microg*h/mL and 7.70 +/- 2.25 microg*h/mL, respectively). Throughout all three studies, cilomilast was well tolerated, and concomitant use of these selective and nonselective inhibitors, although unlikely in the clinic, is hypothetically feasible. Taken together, these studies clearly differentiate cilomilast from theophylline for drug-drug liability issues in a smoker and nonsmoker population, as well as highlight the potential to switch from one drug to another without undue clinical concern.

[Efficacy of new antiepileptic drugs and the next generation drugs]

Recent development and success in the field of new antiepileptic drug treatment, has resulted in the commercialization of many new drugs. The efficacy of these drugs has been assessed in many countries. Despite the progress in USA and European countries, a time lag of approximately 10 years concerning these new drugs exists in Japan. Since 2000, the above mentioned new drugs have been commercially available and are used to treat many patients with refractory epileptic seizures and verify their efficacy as well in Japan. Induced pluripotent stem (iPS) cells, which were invented in Japan are expected to accelerate the invention of more effective antiepileptic drugs in the near future.

Pharmacological studies of bronchial constriction inhibited by parasympatholytics and cilomilast using equine precision-cut lung slices

Equine precision cut lung slices (PCLS) were used to evaluate the ability of several pharmacologic compounds, parasympatholytics atropine, ipratropium, tiotropium and phosphodiesterase (PDE) 4-inhibitor cilomilast, to inhibit methacholine (MCh) induced bronchial constriction. The study war performed using vital lung samples from 20 horses, harvested immediately after euthanasia and lung examination.Tissue samples from the cranial, caudal and accessory lobe were taken for histological examination. Viability in PCLS of 250 +/- 20 microm was confirmed by observation of cilia movement and bronchial contraction in response to the addition of increasing concentrations of MCh (10(-8) to 10(-4) mol/l). Washing in pure RPMI-medium resulted in bronchial reopening. After incubation (20 minutes in an RPMI-solution containing cilomilast (10(-5) mol/l), atropine, ipratropium or tiotropium (10(-7) mol/l) each group (randomized, placebo controlled) was treated with MCh again. After reopening the unaffected viability of the PCLS was confirmed by the addition of MCh. EC50 values were calculated from bronchial cross-sections for each contraction. EC50 values significantly increased after atropine, ipratropium and tiotropium addition. No difference was found for cilomilast and in control slices. Statistical analysis showed a large interindividual, but a small intraindivual variability. No correlation was found between the clinical examination, histological findings and PCLS' responsiveness. We were able to confirm Vietmeier's (2007) values for the responsiveness of equine PCLS to MCh and to proof the effect of several new bronchodilatators using a new technique that allows the assessment of several substances in the same horse.

[Selective phosphodiesterase-4 (PDE-4) inhibitors in COPD]

Chronic obstructive pulmonary disease (COPD) is a worldwide health problem resulting in significant morbidity and mortality; however, it could not be understood totally so far. Treatment options for the disease are quite limited and there is an urgent need for new treatment strategies. Among new therapeutic agents that are under development, a group of significant importance is phosphodiesterase-4 (PDE-4) inhibitors shown to have antiinflammatory actions. Phosphodiesterases are the enzymes responsible from the breakdown and inactivation of cyclic adenosine monophosphate (cAMP) which is an intracellular second messenger molecule. They are present in several structural and inflammatory cells, in these cells the inactivation of cAMP results in a proinflammatory cascade. So, in COPD which goes together with chronic inflammation, prevention of cAMP inactivation via phosphodiesterase enzyme inhibition made phosphodiesterase enzymes potential targets. Main phosphodiesterase playing a part in COPD is PDE-4 which is predominantly present in inflammatory cells and airway smooth muscle cells. The studies therefore focused on inhibitors selective to PDE-4 subtype. The two selective PDE-4 inhibitors that are at Phase III clinical trial stage are cilomilast and roflumilast. The studies have demonstrated that antiinflammatory effects of cilomilast and roflumilast positively contribute to the respiratory function, frequency of exacerbations and quality of life of COPD patients. Despite we need new studies to evaluate the influence of these agents on the natural course of COPD as well as their long-term safety; we can certainly comment that cilomilast and roflumilast are promising hope in COPD treatment by their clinical and antiinflammatory effects.

Evaluation of oral corticosteroids and phosphodiesterase-4 inhibitor on the acute inflammation induced by inhaled lipopolysaccharide in human

BACKGROUND

Endotoxins are pro-inflammatory substances present in the environment. In man, inhalation of its purified derivative lipopolysaccharide (LPS) induces inflammation related to macrophages and neutrophils. Corticosteroids and phosphodiesterase (PDE)-4 inhibitors have inhibiting effects on macrophages and neutrophils, respectively. This study investigated the effect of prednisolone and of the PDE-4 inhibitor cilomilast on the LPS-induced acute inflammation.

METHODS

The study was a placebo-controlled, double-blind crossover design. On three occasions, at 2 weeks interval, 16 healthy subjects inhaled 50 microg LPS after a 6-day treatment with cilomilast (15 mg bd), prednisolone (10 mg bd) or placebo. For the assessment of the inflammatory response, induced sputum was obtained before inclusion and 6h post-LPS while blood samples were collected before, 6 and 24 h post-LPS.

RESULTS

Inhaled LPS induced an increase in sputum neutrophils (p<0.0001), logMMP-9 (p<0.05), logMMP-9/TIMP-1 (p<0.01) and logTNF-alpha (p<0.02). At the blood level there were significant rise in neutrophilia (p<0.001), E-selectin (p<0.02), C-reactive protein (CRP) (p<0.001) and LPS-binding protein (p<0.001). There was both a slight, but not significant, increase in body temperature and decrease in forced expiratory volume in 1 s (FEV(1)). Neither prednisolone nor cilomilast had protective effect on the LPS-induced airways' inflammation. The LPS-induced CRP acute-phase protein of inflammation (0.58+/-0.13 and 3.52+/-0.41 mg/dL, before and after LPS, respectively) was significantly inhibited by a pre-treatment with prednisolone (1.39+/-0.32 mg/dL, p<0.01) and attenuated (2.65+/-0.30 mg/dL, p=0.09) with cilomilast.

CONCLUSION

In healthy subjects, while the LPS-induced airways' inflammation was not modified either by oral prednisolone or by PDE-4 inhibitor cilomilast (at actual dosage), the LPS-induced acute phase of blood inflammation was reduced by prednisolone.

Phosphodiesterase 4 inhibitors augment levels of glucocorticoid receptor in B cell chronic lymphocytic leukemia but not in normal circulating hematopoietic cells

Type 4 cyclic AMP (cAMP) phosphodiesterase (PDE4) inhibitors, a class of compounds in clinical development that activate cAMP-mediated signaling by inhibiting cAMP catabolism, offer a feasible means by which to potentiate glucocorticoid-mediated apoptosis in lymphoid malignancies such as B-cell chronic lymphocytic leukemia (B-CLL). In this study, we show that PDE4 inhibitors up-regulate glucocorticoid receptor (GRalpha) transcript levels in B-CLL cells but not T-CLL cells or Sezary cells or normal circulating T cells, B cells, monocytes, or neutrophils. Because GRalpha transcript half-life does not vary in CLL cells treated with the prototypic PDE4 inhibitor rolipram, the 4-fold increase in GRalpha mRNA levels observed within 4 h of rolipram treatment seems to result from an increase in GRalpha transcription. Rolipram treatment increases levels of transcripts derived from the 1A3 promoter to a greater extent than the 1B promoter. Treatment of B-CLL cells with two other PDE4 inhibitors currently in clinical development also augments GR transcript levels and glucocorticoid-mediated apoptosis. Washout studies show that simultaneous treatment with both drug classes irreversibly augments apoptosis over the same time frame that GR up-regulation occurs. Although treatment of B-CLL cells with glucocorticoids reduces basal GRalpha transcript levels in a dose-related manner, cotreatment with rolipram maintained GRalpha transcript levels above baseline. Our results suggest that as a result of their unusual sensitivity to PDE4 inhibitor-mediated up-regulation of GRalpha expression, treatment of B-CLL patients with combined PDE4 inhibitor/glucocorticoid therapy may be of therapeutic benefit in this disease.

Advances in pharmacologic agents in imaging: new A2A receptor agonists

Pharmacologic stress myocardial perfusion imaging is being performed with increasing frequency over exercise stress. Dipyridamole and adenosine have a high side-effect profile, provide higher than needed coronary artery flow rates, and use a relatively complicated method of administration. Based on preclinical animal work, three selective adenosine A2A receptor agonists, regadenoson (CVT3146), binodenoson (MRE0470 or WRC0470), and apadenoson (BMS068645 or ATL146e), may overcome these limitations and are now in Phase III studies as pharmacologic stress agents. For single-photon emission CT imaging, binodenoson and regadenoson were concordant with adenosine images for detection and quantitation of ischemia. Despite the high A2A selectivity of binodenoson and regadenoson in preclinical studies, subjective side effects attributable to other adenosine receptor subtypes were still observed in human studies and are similar to or slightly lower than adenosine. There have been no reports of atrioventricular block or bronchospasm with either regadenoson or binodenoson in published trials.

Cilomilast

The central role of cyclic nucleotides as intracellular second messengers dates back almost 50 years. The importance of phosphodiesterase in regulating this system was recognized early, and the potential therapeutic role of phosphodiesterase inhibitors in modulating pathologic conditions was also suggested. At that time, the methylxanthines represented major pharmacologic agents capable of inhibiting cyclic nucleotides and were widely used in respiratory medicine. Initially, bronchodilator effects were considered their major mechanism of action, but subsequent studies suggested other potential roles including an anti-inflammatory one. A number of developments led to the decline in popularity of this class of agents, the foremost being their side-effect profile. The discovery of multiple phosphodiesterase isoforms paired with a better understanding of the physiologic and clinical properties of the phosphodiesterases has re-awakened interest in therapeutic agents in this area and in particular the potential for the development of selective phosphodiesterase inhibitors. Cilomilast is a systemically available, second- generation, selective phosphodiesterase-4 inhibitor. It retains the therapeutic activity of the first generation phosphodiesterase-4 inhibitors (such as rolipram) but is believed to have less of an emetic effect. Cilomilast causes a reduction of tissue cells considered central to the ongoing inflammatory process (macrophages and CD8+ lymphocytes) in patients with chronic obstructive pulmonary disease. Chronic obstructive pulmonary disease is now considered a chronic inflammatory disease of the lungs resulting from prolonged exposure to inflammatory agents in cigarette smoke and other environmental and occupational pollutants, and it is currently the principal target of cilomilast. It is characterized by progressive destruction of parenchymal tissue and punctuated by acute exacerbations. The inflammation is thought to begin in the peripheral airways and lung parenchyma. Chronic obstructive pulmonary disease is a progressive disease, leading to disability and eventual death despite conventional therapy. Cilomilast is completely absorbed following oral administration and has negligible first-pass metabolism. It exhibits low between-subject variability. Cilomilast is predominantly protein bound. Plasma clearance is almost entirely metabolic, through multiple parallel pathways. Its terminal elimination half-life is approximately 6.5 hours, and steady state is rapidly achieved. A dose of 15 mg twice daily has been found to be clinically effective. Smoking and age have no clinically relevant effects on cilomilast pharmacokinetics. Most drugs frequently used in patients with chronic obstructive pulmonary disease do not alter its side effect profile. Initial concerns of arteritis involving the gastrointestinal tract in rodent animal models have not been reported in clinical trials. Nausea, presumably of central origin, is the principal adverse reaction seen in healthy subjects taking cilomilast. It has not been associated with the serious cardiac or neurological adverse effects seen with theophylline. Preliminary clinical studies suggest a favorable clinical effect in chronic obstructive pulmonary disease. Cilomilast is generally well tolerated and has not generated safety concerns in reported clinical studies.

PDE4B5, a Novel, Super-Short, Brain-Specific cAMP Phosphodiesterase-4 Variant Whose Isoform-Specifying N-Terminal Region Is Identical to That of cAMP Phosphodiesterase-4D6 (PDE4D6)

The cAMP-specific phosphodiesterase-4 (PDE4) gene family is the target of several potential selective therapeutic inhibitors. The four PDE4 genes generate several distinct protein-coding isoforms through the use of alternative promoters and 5'-coding exons. Using mouse transcripts, we identified a novel, super-short isoform of human PDE4B encoding a novel 5' terminus, which we label PDE4B5. The protein-coding region of the novel 5' exon is conserved across vertebrates, chicken, zebrafish, and fugu. Reverse-transcription-polymerase chain reaction (PCR) and quantitative (PCR) measurements show that this isoform is brain-specific. The novel protein is 58 +/- 2 kDa; it has cAMP hydrolyzing enzymatic activity and is inhibited by PDE4-selective inhibitors rolipram and cilomilast (Ariflo). Confocal and subcellular fractionation analyses show that it is distributed predominantly and unevenly within the cytosol. The 16 novel N-terminal residues of PDE4B5 are identical to the 16 N-terminal residues of the super-short isoform of PDE4D (PDE4D6), which is also brain-specific. PDE4B5 is able to bind the scaffold protein DISC1, whose gene has been linked to schizophrenia. Microarray expression profiling of the PDE4 gene family shows that specific PDE4 genes are enriched in muscle and blood fractions; however, only by monitoring the individual isoforms is the brain specificity of the super-short PDE4D and PDE4B isoforms revealed. Understanding the distinct tissue specificity of PDE4 isoforms will be important for understanding phosphodiesterase biology and opportunities for therapeutic intervention.

Effects of cyclosporin A and cilomilast on activated canine, murine and human keratinocytes

The calcineurin inhibitor cyclosporin A and the phosphodiesterase 4 inhibitor cilomilast exhibit potent immunomodulatory properties which make them interesting therapeutics for the treatment of skin disorders like canine and human atopic dermatitis. Cyclosporin A and phosphodiesterase 4 inhibitors have already demonstrated clinical efficacy in the therapy of canine and human atopic dermatitis. Their direct impact on keratinocytes, especially canine keratinocytes, is less obvious. Thus, an investigation was carried out to ascertain whether cyclosporin A and cilomilast modulate keratinocyte proliferation and secretion of proinflammatory mediators. Cyclosporin A inhibited canine and murine keratinocyte proliferation, whereas cilomilast had no affect. Cyclosporin A and cilomilast reduced the lipopolysaccharide-induced prostaglandin E2 synthesis in canine and murine keratinocytes. Both immunomodulators also inhibited the production of the CXC chemokine KC and CCL2 in the murine keratinocyte cell line MSC-P5. The two immunomodulators also significantly reduced the interferon-gamma-induced production of interferon-gamma-inducible protein 10 in human keratinocytes (HaCaT cells). Thus, cyclosporin A and cilomilast directly modulate keratinocyte functions which might contribute to the anti-inflammatory and immunomodulatory action of these compounds in the treatment of allergic skin diseases.

L-454,560, a potent and selective PDE4 inhibitor with in vivo efficacy in animal models of asthma and cognition

Type 4 phosphodiesterases (PDE4) inhibitors are emerging therapeutics in the treatment of a number of chronic disorders including asthma, chronic obstructive pulmonary disease (COPD) and cognitive disorders. This study delineates the preclinical profile of L-454,560, which is a potent, competitive and preferential inhibitor of PDE4A, 4B, and 4D with IC50 values of 1.6, 0.5 and 1.2 nM, respectively. In contrast to the exclusive binding of cilomilast and the preferential binding of roflumilast to the PDE4 holoenzyme state (Mg2+-bound form), L-454,560 binds to both the apo-(Mg2+-free) and holoenzyme states of PDE4. The intrinsic enzyme potency for PDE4 inhibition by L-454,560 also results in an effective blockade of LPS-induced TNFalpha formation in whole blood (IC50 = 161 nM) and is comparable to the human whole blood potency of roflumilast. The cytokine profile of inhibition of L-454,560 is mainly a Th1 profile with significant inhibition of IFNgamma and no detectable inhibition of IL-13 formation up to 1 microM. L-454,560 was also found to be efficacious in two models of airway hyper-reactivity, the ovalbumin (OVA) sensitized and challenged guinea pig and the ascaris sensitized sheep model. Furthermore, L-454560 was also effective in improving performance in the delayed matching to position (DMTP) version of the Morris watermaze, at a dose removed from that associated with potential emesis. Therefore, L-454,560 is a novel PDE4 inhibitor with an overall in vivo efficacy profile at least comparable to roflumilast and clearly superior to cilomilast.

An update and appraisal of the cilomilast Phase III clinical development programme for chronic obstructive pulmonary disease

Cilomilast (Ariflo, SB 207499) is an orally active, second-generation phosphodiesterase (PDE) 4 inhibitor that is being developed by GlaxoSmithkline for the treatment of chronic obstructive pulmonary disease (COPD). The results of Phase I and Phase II studies have demonstrated that cilomilast significantly improves lung function and quality of life to a clinically meaningful extent, which has led to a comprehensive Phase III programme of research evaluating efficacy, safety and mechanism of action. However, the results of those Phase III studies are unremarkable and disappointing, raising doubt over the future of cilomilast as a novel therapy for COPD. This review summarizes data obtained from the Phase III clinical development programme, highlights some of the potential concerns both specific to cilomilast and to PDE4 inhibitors in general and assesses the likelihood that cilomilast will reach the market.

Differential effects of phosphodiesterase PDE-3/PDE-4-specific inhibitors on vasoconstriction and cAMP-dependent vasorelaxation following balloon angioplasty

It is known that cAMP and cGMP are important for vasorelaxation, and cyclic nucleotide phosphodiesterases (PDEs) regulate their levels. Balloon angioplasty (BAL) is associated with reduced cAMP and cGMP levels, and inhibition of PDE-3 reduces restenosis. In this study, we found that BAL increased PDE-3 activity, which affected vasoreactivity of rat aortic rings 24-h post-BAL; these were compared with intact (INT) and ex vivo endothelium-denuded rings (RUB) from sham rats. In BAL and RUB rings, vasorelaxant responses to ACh were abolished. The EC(50) for phenylephrine (PE) was 1.8-fold less in RUB than in INT or BAL, whereas the maximal contractile effect of PE was greater in BAL than in INT or RUB. PDE-3 inhibitors reduced the maximal response to PE by >65% in BAL compared with 10-30% in INT and RUB; the reduction of the maximal response to U-46619 was 37% in BAL compared with 8% in INT with no reduction in RUB. PDE-4 inhibitors reduced PE-induced tone by <30% in an endothelium-dependent manner. Vasorelaxant responses to agonists that utilize cAMP were greatly impaired in BAL and RUB rings, and inhibition of PDE-3 enhanced the vasorelaxant responses in BAL or RUB. Inhibition of PDE-4 increased vasorelaxant responses to isoproterenol (ISO) to a much lesser degree. Thus PDE-3 and PDE-4 inhibitors exhibited differential effects on PE-induced tone and vasorelaxant responses to ISO. Inhibition of PDE-3 also produced a greater increase in cAMP in BAL than INT or RUB rings. These results suggest that increased PDE-3 activity after BAL may promote a vasospastic state and that the reduction in cAMP may, possibly, influence vessel remodeling.

Making Sense of the Evidence Regarding Nonhormonal Treatments for Hot Flashes

The demand for nonhormonal interventions for hot flashes is increasing because of the number of patients diagnosed with hormone-sensitive cancers and the results of the Women's Health Initiative indicating that hormone replacement therapy is not as beneficial as originally believed. Since 2002, numerous studies testing nonhormonal treatments for hot flashes have been conducted. Clinicians need to be able to use these research findings to help patients make treatment decisions. Because hot flashes can interfere with activities of daily living such as sleep and work, clinicians first should assess the extent to which hot flashes are disruptive to a woman's life. The evidence for nonhormonal interventions is summarized, and a decision treatment algorithm is offered for use in clinical practice. This algorithm includes nonhormonal options of the antidepressants available in addition to gabapentin, an antiseizure medication. A short review of the evidence for possible complementary therapies also is included.

[Newer antiepileptic drugs]

Ten newer antiepileptic drugs have been developed since 1990s. These drugs have wider therapeutic spectra, fewer side-effects, and lesser drug-to-drug interactions compared with the older typical antiepileptic drugs. Among them, zonisamide was developed in Japan and has been used from 1989. Gabapentin was at length approved in 2006. The other newer antiepileptic drugs are not approved yet in Japan. Felbamate can not be used in Europe because it may induce lethal hepatic toxicity and aplastic anemia. Vigabatrin is not approved in USA because it may induce permanent visual field deficit. The USA guideline for epilepsy treatment recommends that patients with newly diagnosed epilepsy can be treated with gabapentin, lamotrigine, topiramate, and oxcarbazepine. In contrast, based on epilepsy treatment guideline in England, newer antiepileptic drugs are considered only when patients with newly diagnosed epilepsy are unable to use the older antiepileptic drugs for some reasons. All newer antiepileptic drugs are used for intractable partial epilepsies, and lamotrigine and topiramate can also be used for idiopathic generalized epilepsies. The response rate (seizure reduction rate with 50% or more) and drop-out rate are overlapping among all newer antiepileptic drugs. Gabapentin, levetiracetam, and pregabalin are eliminated from kidney, and they had no drug-to-drug interactions and can be titrated rapidly. The serum concentration of lamotrigine is decreased with co-administration of hepatic enzyme inducing drugs and is increased with co-administration of valproic acid. Hypersensitivity reactions are rare with gavapentin, levetiracetam, topiramate, and tiagabin. Psychoses are reported to be induced with zonisamide, however, they can be induced with the other newer drugs (topiramate, levetiracetam, etc.). Drug-induced psychiatric symptoms, especially depression, may be often underdiagnosed. Many of these newer drugs (gabapentine, lamotrigine, levetiracetam, oxycarbazepine, etc.) have effects on chronic neuropathic pain. Some newer drugs show mood stabilizing effects (lamotrigine, oxycarbazepine, etc.), or antianxiety effect (gabapentin, topiramate, levetiracetam, pregavalin, etc.). Wide range of action to central nervous system of these newer antiepileptic drugs may serve not only for clinical seizure suppression, but also for neuroprotection.