Central Nervous System-related Side Effects Research Articles

Lasmiditan abortive therapy for episodic migraine in Phase II/III randomized clinical trials: A meta-analysis.

Although migraine is common, there are very few treatment options. Recently, lasmiditan, a specific 5-HT1F agonist, has gained approval as abortive therapy for migraine. This meta-analysis and trial sequential analysis (TSA) was performed to analyze efficacy and tolerability of lasmiditan therapy for episodic migraine. Phase II and Phase III double-blinded placebo-controlled randomized controlled trials (RCTs) evaluating lasmiditan for episodic migraine were searched for from electronic databases. The risk of bias was estimated, data were extracted, and relative risk (RR) were calculated for efficacy and safety outcomes with a fixed/random effect model. Forest plots and funnel plots were created. TSA graph was plotted. Therapeutic gain with lasmiditan was calculated. Six high-quality RCTs were included with 7122 patients. Compared to placebo, lasmiditan demonstrated a significant proportion of migraineurs reporting freedom from headache, most bothersome symptom, headache response, no disability, global impression "very much/much better" 2 h posttreatment and sustained pain freedom at 24 and 48 h with 50, 100, 200, and 400 mg doses (RR range = 1.26-2.50). 39.3% of patients in the lasmiditan group (RR = 2.43) reported one or more treatment-emergent adverse event (TEAE). Dizziness, somnolence, paresthesia, fatigue, nausea, vertigo, hypoesthesia, asthenia, muscular weakness, lethargy, and malaise had a high incidence (RR range = 3.16-12.77). Most TEAEs were mild to moderate. No vasoconstriction-related TEAE was reported. Lasmiditan demonstrated efficacy as abortive therapy for episodic migraine with central nervous system-related side effects.

In silico discovery of potential azole-containing mPGES-1 inhibitors by virtual screening, pharmacophore modeling and molecular dynamics simulations

Inhibition of microsomal prostaglandin E2 synthase-1 (mPGES-1) is promising for designing novel nonsteroidal anti-inflammatory drugs, as they lack side-effects associated with inhibition of cyclooxygenase enzymes. Azole compounds are nitrogen-containing heterocycles and have a wide use in medicine and are considered as promising compounds in medicinal chemistry. Various computer-aided drug design strategies are incorporated in this study. Structure-based virtual screening was performed employing various docking programs. Receiver operator characteristic (ROC) curves were used to evaluate the selectivity of each program. Furthermore, scoring power of Autodock4 and Autodock Vina was assessed by Pearson’s correlation coefficients. Pharmacophore models were generated and Güner-Henry score of the best model was calculated as 0.89. Binding modes of the final 10 azole compounds were analyzed and further investigation of the best binding (− 8.38 kcal/mol) compound was performed using molecular dynamics simulation, revealing that furazan1224 (ZINC001142847306) occupied the binding site of the substrate, prostaglandin H2 (PGH2) and remained stable for 100 ns. Continuous hydrogen bonds and hydrophobic interactions with amino acids in the active site supported the stability of furazan1224 throughout the trajectory. Pharmacokinetic profile showed that furazan1224 lacks the risks of inhibiting cytochrome P450 3A4 enzyme and central nervous system-related side-effects.

DARK Classics in Chemical Neuroscience: Loperamide.

Loperamide, a popular and inexpensive over-the-counter antidiarrheal medicine, is a potent μ-opioid receptor agonist approved by the U.S. Food and Drug Administration (FDA). It has been on the market since 1976 and is relatively safe with no central nervous system-related side effects when used for a short period of time at the recommended therapeutic dose (2-8 mg/day). In recent years, loperamide has become notoriously known as the "poor man's methadone" for people with substance dependence due to the increase in loperamide overdoses from self-administered medication to treat opioid withdrawal symptoms. As a result, in 2018, the FDA decided to limit the available packaged dose of loperamide to stop prominent abuse. This review provides the synthesis and chemical properties of loperamide as well as the pharmacology and adverse effects of its use and the social effects of such abuse.

Long-term efficacy and safety of solifenacin in pediatric patients aged 6 months to 18 years with neurogenic detrusor overactivity: results from two phase 3 prospective open-label studies

The standard recommended treatment for neurogenic detrusor overactivity (NDO) is clean intermittent catheterization combined with an antimuscarinic agent. However, the adverse systemic side-effects of oxybutynin, the most widely used agent, are of concern. To evaluate the efficacy and safety of solifenacin in pediatric patients with NDO, aged 6 months-<5 years and 5-<18 years. Two open-label, baseline-controlled, phase 3 studies were conducted in pediatric patients with NDO. Patients were treated with sequential doses of solifenacin oral suspension (pediatric equivalent doses 2.5-10mg) for 12 weeks to determine each patient's optimal dose, followed by a fixed dose ≥40-week treatment period. Primary efficacy endpoint was change from baseline in maximum cystometric capacity (MCC) after 24 weeks. Secondary endpoints included bladder compliance, bladder volume until first detrusor contraction (>15 cmH2O), number of overactive detrusor contractions (>15 cmH2O), maximum catheterized volume (MCV)/24h, and incontinence episodes/24h. Safety parameters were treatment-emergent adverse events (TEAEs), serious adverse events, laboratory variables, vital signs, electrocardiograms, and ocular accommodation and cognitive function assessments. After 24 weeks, MCC had significantly increased compared with baseline in patients aged 6 months -<5 years and 5-<18 years (37.0ml and 57.2ml, respectively; P<0.001; Fig.). Improvement was also observed after 52 weeks' treatment. Significant changes were observed from baseline to week 24 in all secondary endpoints in both age groups: increase in bladder compliance, increase in bladder volume to first detrusor contraction as a percentage of expected bladder capacity, reduction in the number of overactive detrusor contractions, increase in MCV, and decreased incontinence episodes. TEAEs were mostly mild or moderate, and there were no new drug-related TEAEs compared with adult studies. Age-related improvements were noted in ocular accommodation and cognitive function. These long-term multicenter investigations demonstrated the efficacy and safety of solifenacin in pediatric patients with NDO. The observed increases in MCC were clinically relevant and demonstrated that an increase in fluid volume can be accommodated in the bladder prior to reaching intravesical pressures that endanger kidney function and/or are associated with leakage or discomfort. Solifenacin was well tolerated with low incidences of constipation and dry mouth (typically associated with antimuscarinics), central nervous system-related side-effects, and facial flushing. Solifenacin was effective and well tolerated in pediatricpatients with NDO, aged 6 months-<18 years, suggesting that it is a viable alternative to oxybutynin, the current standard of care. STUDIES ARE REGISTERED AT CLINICALTRIALS.GOV: NCT01981954 and NCT01565694.

TAS-203, an oral phosphodiesterase 4 inhibitor, exerts anti-inflammatory activities in a rat airway inflammation model

Cyclic adenosine monophosphate (cAMP) is a key intracellular second messenger, which is degraded by phosphodiesterase 4 (PDE4). PDE4 suppresses cAMP levels, and thus stimulates the activity of inflammatory cells. Therefore, PDE4 has been considered as a therapeutic target for airway inflammatory diseases including asthma and chronic obstructive pulmonary disease (COPD). Roflumilast, an approved PDE4 inhibitor, has been shown to have clinical benefits in COPD. However, central nervous system-related side effects including nausea and vomiting have limited the therapeutic index of roflumilast. Moreover, although airway mucus hypersecretion is the characteristic feature, which is associated with the severity and prognosis, the inhibitory effect of roflumilast on sputum production is limited to a minority of patients. In this study, we demonstrate the inhibitory effects of TAS-203, which is an orally active PDE4 inhibitor associated with a lowered emetic effect, on airway inflammation and mucus hypersecretion. A cell-based assay showed TAS-203 treatment suppressed epidermal growth factor (EGF)-induced mucin MUC5AC expression. TAS-203 also suppressed monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-5 and IL-13 production in a Sephadex-induced airway inflammation model, and the number of infiltrating cells in bronchoalveolar lavage (BAL) fluid. TAS-203 caused marked reduction of goblet cell hyperplasia in a histopathological analysis of airway epithelium. Furthermore, TAS-203 suppressed 5-hydroxytryptamine (5-HT)-induced airway hyperresponsiveness (AHR). In addition, we preliminarily confirmed TAS-203 prevents airway MUC5AC production in BAL fluid, and shows lower specific airway resistance (sRaw) in a cigarette smoke-induced COPD-like model. Our data suggest that TAS-203 might be useful in the treatment of airway inflammatory disease.

In Vitro Liberation of Indomethacin from Chitosan Gels Containing Microemulsion in Different Dissolution Mediums

The objective of this research is to outline the liberation of indomethacin from different chitosan gels containing O/W microemulsion. The influence of surfactant, sodium lauryl sulfate, in two concentrations (0.5% and 0.75%, w/w) was determined in dissolution medium on the release of indomethacin, which was used as poor water-soluble model drug. Chitosan gels were prepared in four different concentrations of chitosan-1%, 1.5%, 2%, and 3% (w/w). Microemulsion enhanced the liberation of the indomethacin from chitosan gels into all dissolution mediums. Adding the surfactant into phosphate-buffered saline decreased the amount of liberated indomethacin from microemulsion, gel mixture, but increased the drug liberation from pure chitosan gels. It was detected that with the increased concentration of chitosan in the samples, the amount of indomethacin liberated (p < 0.05) also increased. A conclusion was drawn that the liberation of indomethacin from chitosan gels was influenced by increased pH of the samples. The high viscosity induced a higher release of indomethacin from 3% (w/w) chitosan hydrogel at pH 5.8 as compared with 3% (w/w) chitosan hydrogel at pH 3.8. The highest percentage of released indomethacin was determined when a mixture of microemulsion gel with higher chitosan content was used.

Can we predict blood brain barrier permeability of ligands using computational approaches?

An ideal neurotherapeutics agent for central nervous system (CNS) molecular targets should cross Blood Brain Barrier (BBB) whereas peripherally acting agent should not cross BBB to avoid CNS related side effects. Hence prediction of BBB permeability index has been proved to be an efficient tool for drug discovery and development. Various experimental and computational approaches are being used in recent past for the prediction of BBB permeability and they have been successful up to some extent. However the accuracy and authenticity of these methods have been under question. The current review article attempts to answer a vital question that is, can we predict BBB permeability using computational approaches.

(R)- and (S)-4-Amino-3-(trimethylsilyl)methylbutanoic acids ameliorate neuropathic pain without central nervous system-related side effects

Neuropathic pain is a chronic pain condition resulting from neuronal damage, and is usually treated with pregabalin or gabapentin, which are structurally related to γ-aminobutyric acid (GABA) and are originally developed as anticonvulsant drugs. Here, we report the synthesis and pharmacology of (R)- and (S)-4-amino-3-(trimethylsilyl)methylbutanoic acids (1a and 1b), which showed analgesic activity as potent as that of pregabalin in the Chung spinal nerve ligation model. However, unlike pregabalin, 1a and 1b do not have antiepileptic effects, and they are therefore promising candidates for selective therapeutic agents to treat neuropathic pain without central nervous system-related side effects.

Anti-HIV Drugs Nevirapine and Efavirenz Affect Anxiety-Related Behavior and Cognitive Performance in Mice

Nevirapine (NVP) and efavirenz (EFV) belong to the class of anti-HIV drugs called non-nucleoside reverse transcriptase inhibitors (NNRTIs), commonly used as part of highly active antiretroviral therapy (HAART). Although the HAART is able to bring down viral load to undetectable levels and restore immune function, their prolonged use causes several adverse effects. It has been demonstrated that both NVP and EFV are able to cross the blood-brain barrier, causing important central nervous system-related side effects. Thus, this study investigated the effects of chronic administration of EFV (10mg/kg) and NVP (3.3mg/kg) in mice submitted to two distinct series of experiments, which aimed to evaluate: (1) the emotional behavior (elevated plus-maze, forced swimming, and open-field test) and (2) the cognitive performance (object recognition and inhibitory avoidance test) of mice. Our results demonstrated that EFV, but not NVP, reduced the exploration to open arms in the elevated plus-maze test. Neither NVP nor EFV altered mouse behavior in the forced swimming and open-field tests. Both drugs reduced the recognition index in the object recognition test, but only EFV significantly impaired the aversive memory assessed in the inhibitory avoidance test 24h after training. In conclusion, our findings point to a genuine anxiogenic-like effect to EFV, since it reduced exploration to open arms of elevated plus-maze test without affecting spontaneous locomotion. Additionally, both drugs impaired recognition memory, while only the treatment with EFV impaired significantly aversive memory.

RDEA119/BAY 869766: A Potent, Selective, Allosteric Inhibitor of MEK1/2 for the Treatment of Cancer

The RAS-RAF-mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase (MEK)-ERK pathway provides numerous opportunities for targeted oncology therapeutics. In particular, the MEK enzyme is attractive due to high selectivity for its target ERK and the central role that activated ERK plays in driving cell proliferation. The structural, pharmacologic, and pharmacokinetic properties of RDEA119/BAY 869766, an allosteric MEK inhibitor, are presented. RDEA119/BAY 869766 is selectively bound directly to an allosteric pocket in the MEK1/2 enzymes. This compound is highly efficacious at inhibiting cell proliferation in several tumor cell lines in vitro. In vivo, RDEA119/BAY 869766 exhibits potent activity in xenograft models of melanoma, colon, and epidermal carcinoma. RDEA119/BAY 869766 exhibits complete suppression of ERK phosphorylation at fully efficacious doses in mice. RDEA119/BAY 869766 shows a tissue selectivity that reduces its potential for central nervous system-related side effects. Using pharmacokinetic and pharmacodynamic data, we show that maintaining adequate MEK inhibition throughout the dosing interval is likely more important than achieving high peak levels because greater efficacy was achieved with more frequent but lower dosing. Based on its longer half-life in humans than in mice, RDEA119/BAY 869766 has the potential for use as a once- or twice-daily oral treatment for cancer. RDEA119/BAY 869766, an exquisitely selective, orally available MEK inhibitor, has been selected for clinical development because of its potency and favorable pharmacokinetic profile.

Weight loss and metabolic effects of topiramate in overweight and obese type 2 diabetic patients: randomized double-blind placebo-controlled trial

To examine the metabolic effects and body composition changes after topiramate treatment of obese type 2 diabetic patients (DM2) for 11 months. Thirty-eight DM2 on diet or sulfonylurea treatment participated in this randomized double-blind placebo-controlled trial. Thirteen placebo-treated and nine topiramate-treated patients completed the trial. Patients were randomized to treatment with topiramate 96 mg b.i.d. or placebo (6-week run-in phase, 2-months titration phase, 9-months maintenance phase). Insulin sensitivity was measured with euglycaemic hyperinsulinemic clamps. Weight, HbA1c, fasting glucose, blood lipids and safety variables were measured at regular intervals. Body composition was determined with computerized tomography. Meal tests were performed to evaluate postprandial glucose and insulin levels. Three-day diet recalls were carried out to evaluate energy ingestion. The mean age was 58.6+/-7.1 years, body weight 98.1+/-16.1 kg, BMI 33.0+/-4.5 kg/m(2), and glycosylated hemoglobin (HbA1c) 7.3+/-0.9%. In topiramate-treated patients, there were significant reductions in HbA1c (1.1+/-0.9%), fasting plasma glucose, body weight (-6.6+/-3.3%), as well as body fat, lean body mass, postprandial glucose and free fatty acid levels but there were no significant changes in insulin sensitivity. The daily average energy intake decreased more in the topiramate group than in the placebo group. Paresthesia and central nervous system-related side effects were the main causes for the dropout rate. Topiramate treatment of overweight DM2 reduced body weight and body fat, and was associated with a marked improvement in glycaemic control whereas no significant improvement in insulin-stimulated glucose uptake was demonstrated. Further studies are required to clarify whether this effect might occur through changes in insulin sensitivity in the liver and/or pancreatic insulin secretion.

Discriminative stimulus effects of the type-4 phosphodiesterase inhibitor rolipram in rats

Rolipram, an inhibitor of cyclic AMP phosphodiesterase (PDE4) produces discriminative stimulus effects in rats. These effects may be related to a wide range of central nervous system effects described previously. The purposes of the present study were to: (i) assess the specificity of the discriminative stimulus effects of rolipram; (ii) examine the role of beta adrenergic receptors; (iii) assess the effects of imipramine and nisoxetine; and (iv) determine whether SKF 38393, a compound which also increases cAMP levels, substitutes for rolipram. Rats were trained to discriminate 0.1 mg/kg rolipram from its vehicle in a two-lever task. Following discrimination training, substitution and antagonism tests were carried out. In generalization tests, the PDE4 inhibitors ICI 63,197 and Ro 20-1724 substituted for rolipram in a dose-dependent manner (substitution at 0.3 mg/kg and 3 mg/kg, respectively). The selective inhibitors of PDE1, PDE2, and PDE5/6 did not substitute for rolipram; however, a dose of 10 mg/kg of the PDE3 inhibitor milrinone did substitute. The beta adrenergic agonists clenbuterol and dobutamine at least partially substituted for rolipram (0.1 mg/kg and 18 mg/kg, respectively). By contrast, the D1 dopaminergic agonist SKF 38393 and the monoamine uptake inhibitors imipramine and nisoxetine were ineffective (at doses up to 3, 10, and 10 mg/kg, respectively). The present results indicate that the discriminative stimulus effects of rolipram are related to the inhibition of the hydrolytic activity of PDE4. Generalized increases in cyclic nucleotides do not appear to be sufficient for producing rolipram-like effects. It appears that a mechanism involving beta adrenergic receptors may contribute to the effects of rolipram, consistent with previous neuropharmacological data. Finally, the discriminative stimulus effects of rolipram appear to be unrelated to its antidepressant-like effect, but may provide a surrogate marker for central nervous system-related side effects of PDE4 inhibitors.

Alprazolam versus buspirone in the treatment of outpatients with generalized anxiety disorder

The efficacy and safety of alprazolam and buspirone for treating generalized anxiety disorder (GAD) were compared in a 6-week, double-blind, randomized, placebo-controlled study of 94 outpatients. Mean daily doses at the end of the study were 1.9 mg alprazolam and 18.7 mg buspirone. As judged by the Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale, Physician's Global Improvement Scale, and other efficacy scales, alprazolam and buspirone were similar in efficacy, but more effective than placebo, for treating anxiety and depression symptoms in these patients. Clinically important differences were noted between drugs in the onset of effect, with alprazolam producing rapid and sustained improvement within the first week of treatment and buspirone producing more gradual, continuous improvement throughout the study. Significantly more buspirone-treated than alprazolam-treated patients failed to complete the study, primarily because of side effects or inefficacy. No clinically important differences were noted between alprazolam and buspirone in side effects, vital signs, or laboratory test results. Alprazolam-treated patients most frequently reported central nervous system-related side effects (drowsiness and sedation), while buspirone-treated patients most frequently reported gastrointestinal system-related side effects (appetite disturbances and abdominal complaints).

Reversing intravenous sedation with flumazenil

This study was designed to evaluate the effects of flumazenil in reversing sedation from midazolam and meperidine after oral surgical procedures. Of the 35 patients entered, efficacy was evaluated in 33 and safety in 34. Patients were tested for sedation, psychomotor skills, and memory during a 3-hour period and at a 24-hour follow-up. Flumazenil almost totally reversed the effects of sedation for approximately 2 hours, after which some loss of effect was observed. A number of central nervous system-related side effects were observed in the flumazenil group, but none of these was considered serious. One patient in the flumazenil group had an episode of hypotension that precluded further testing.

Cerebral blood flow and indomethacin drug levels in subjects with and without central nervous side effects.

1. Central nervous system (CNS) side effects are observed during treatment with all nonsteroidal anti-inflammatory drugs (NSAIDs) but their effects are more common during treatment with indomethacin. 2. The aim of the study was to elucidate the mechanism of the CNS related side effects of indomethacin. Two groups were obtained, one with (n = 11), and one without (n = 7), CNS symptoms. Cerebral blood flow was measured in these groups with Doppler equipment, indomethacin levels with h.p.l.c. and CNS symptoms graded on a VAS scale. 3. Blood flow was reduced by 18-30% and was most marked 60 min after dose and did not differ between the two groups. The maximum CNS effect coincided with indomethacin peak levels 60-70 min after dose. These results could implicate that CNS symptoms may be related to indomethacin levels in sensitive patients.

Beta-adrenoceptor blockers and the blood-brian barrier.

1 This study on 21 neurosurgical patients was set up to investigate the extent to which four chronically administered beta-adrenoceptor blockers, propranolol, oxprenolol, metoprolol and atenolol, cross and blood-brain barrier and enter the cerebrospinal fluid (CSF) and brain tissue. The concentration in the CSF of the three lipophilic beta-adrenoceptor blockers, propranolol, oxprenolol and metoprolol, approximated to the free drug concentration in the plasma, and was a poor predictor of brain concentration. These three lipophilic beta-adrenoceptor blockers appeared in brain tissue at concentrations 10-20 times greater than that of hydrophilic atenolol. The approximate brain/plasma ratio for propranolol was 26, for oxprenolol 50, for metoprolol 12 and for atenolol 0.2. 2 The low concentration of atenolol in brain tissue is possibly responsible for the low incidence of central nervous system-related side effects in patients on this agent compared to lipophilic beta-adrenoceptor blockers.

Beta-Adrenoreceptor-blocking agents and the blood-brain barrier.

1. Sixteen neurosurgical patients received (oral) beta-adrenoreceptor-blocking agents (beta-receptor blockers) for 3-22 days. 2. Lipophilic beta-receptor blockers (propranolol) and metoprolol appeared in cerebrospinal fluid at concentrations similar to the free drug plasma concentration. 3. Cerebrospinal fluid concentrations of beta-receptor blockers were poor predictors of brain concentrations. 4. Both lipophilic beta-receptor blockers appeared in high concentrations in the brain: the brain/plasma ratio was approximately 15:1. 5. Hydrophilic atenolol appeared at low concentrations in brain tissue (about 20 times lower than the lipophilic beta-receptor blockers): the brain/plasma ratio was approximately 0.1:1. 6. Central nervous system-related side effects associated mainly with lipophilic beta-receptor blockers possibly result from high brain tissue concentrations.