Therapeutic innovation in Parkinson's disease: a 2020 update on disease-modifying approaches.

Introduction: Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting more than 10 million patients worldwide. Despite increasing improvements in disease management, a huge medical need still exists as its relentless progression cannot be delayed by current treatments. Therefore, scientists, clinicians, and pharmaceutical companies are hunting new drugs with 'disease-modifying' properties.

Safinamide's potential in treating nondystrophic myotonias: Inhibition of skeletal muscle voltage-gated sodium channels and skeletal muscle hyperexcitability in vitro and in vivo.

The antiarrhythmic sodium-channel blocker mexiletine is used to treat patients with myotonia. However, around 30% of patients do not benefit from mexiletine due to poor tolerability or suboptimal response. Safinamide is an add-on therapy to levodopa for Parkinson's disease.

Effects of safinamide on the glutamatergic striatal network in experimental Parkinson's disease.

Objective: The aim of the study was to evaluate electrophysiological effects of safinamide on the intrinsic and synaptic properties of striatal spiny projection neurons (SPNs) and to characterize the possible therapeutic antiparkinsonian effect of this drug in dopamine (DA) denervated rats before and during levodopa (l-DOPA) treatment.

Background: Current therapeutic options in Parkinson's disease (PD) are primarily DA replacement strategies that usually cause progressive motor fluctuations and l-DOPA-induced dyskinesia (LIDs) as a consequence of SPNs glutamate-induced hyperactivity. As a reversible and use-dependent inhibitor of voltage-gated sodium channels, safinamide reduces the release of glutamate and possibly optimize the effect of l-DOPA therapy in PD.

Safinamide inhibits in vivo glutamate release in a rat model of Parkinson's disease.

To investigate whether the reversible MAO-B inhibitor and sodium channel blocker safinamide impairs glutamate release under parkinsonian conditions in vivo, and this effect is dependent on MAO-B inhibition, safinamide (and rasagiline as a comparator) were administered to 6-hydroxydopamine hemilesioned rats, a model of Parkinson's disease, and haloperidol-treated rats, a model of neuroleptic-induced parkinsonism. A microdialysis probe was implanted in the dopamine-depleted dorsolateral striatum, globus pallidus, subthalamic nucleus or substantia nigra reticulata of 6-hydroxydopamine hemilesioned rats. Glutamate and GABA release was stimulated by reverse dialysis of veratridine, and safinamide or rasagiline were acutely administered before veratridine at doses inhibiting MAO-B >50%.

Long-Term Effects of Safinamide on Mood Fluctuations in Parkinson's Disease.

Background: Mood disorders are very frequent in Parkinson's Disease (PD), and their effective treatment is still a major unresolved issue: growing evidence suggests that glutamatergic system dysfunction is directly involved. Safinamide is a drug with an innovative mechanism of action, dopaminergic and non-dopaminergic, that includes the reversible inhibition of the monoamine oxidase-B (MAO-B) enzyme and the modulation of excessive glutamate release through the use- and state-dependent blockade of the sodium channels.

Objective: To investigate the effects of safinamide on mood over two-year treatment in PD patients with motor fluctuations.

Metabotropic glutamate receptor 5: a target for migraine therapy.

Introduction: Many patients suffering from migraine gain little relief from existing treatments partly because many existing acute and preventive therapies used in migraine have been adopted from other neurologic conditions such as depression or epilepsy. Here, we present data supporting a new migraine-specific target, the mGlu5 receptor.

Methods: We studied the effect of mGlu5 blockade using ADX10059, on neuronal firing in the trigeminocervical complex (TCC) and durovascular effects of nociceptive trigeminovascular activation in the anesthetized rat.

A Phase 2A Trial of the Novel mGluR5-Negative Allosteric Modulator Dipraglurant for Levodopa-Induced Dyskinesia in Parkinson's Disease.

Background: The metabotropic glutamate receptor 5-negative allosteric modulator dipraglurant reduces levodopa-induced dyskinesia in the MPTP-macaque model. The objective of this study was to assess the safety, tolerability (primary objective), and efficacy (secondary objective) of dipraglurant on levodopa-induced dyskinesia in Parkinson's disease (PD).

Methods: The study was a phase 2A double-blind, placebo-controlled, randomized (2:1), 4-week, parallel-group, multicenter dose-escalation (from 50 mg once daily to 100 mg 3 times daily) clinical trial involving 76 PD subjects with moderate to severe levodopa-induced dyskinesia.

Eltoprazine counteracts l-DOPA-induced dyskinesias in Parkinson's disease: a dose-finding study.

In advanced stages of Parkinson's disease, serotonergic terminals take up L-DOPA and convert it to dopamine. Abnormally released dopamine may participate in the development of L-DOPA-induced dyskinesias. Simultaneous activation of 5-HT1A and 5-HT1B receptors effectively blocks L-DOPA-induced dyskinesias in animal models of dopamine depletion, justifying a clinical study with eltoprazine, a 5-HT1A/B receptor agonist, against L-DOPA-induced dyskinesias in patients with Parkinson's disease.

The mGluR5 negative allosteric modulator dipraglurant reduces dyskinesia in the MPTP macaque model.

Background: Blocking metabotropic glutamate receptor type 5 (mGluR5) has been proposed as a target for levodopa-induced dyskinesias (LID) in Parkinson's disease (PD). We assessed the effect on LID of dipraglurant, a potent selective mGluR5 receptor negative allosteric modulator in the gold-standard LID macaque model.

Methods: Dipraglurant (3, 10, and 30 mg/kg, by mouth) was tested in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) macaque model of LID in a four-way crossover, single-dose, controlled study (n = 8).

Rapid responders to frovatriptan in acute migraine treatment: results from a long-term, open-label study.

Background: The chronic nature of migraine and the reliance on acute treatment constitute the basis of the present long-term, open-label study.

Objectives: First, assessment of the tolerability and safety of frovatriptan, 2.5-7.

Topical eutectic mixture for premature ejaculation (TEMPE): a novel aerosol-delivery form of lidocaine-prilocaine for treating premature ejaculation.

Objective: To evaluate, in a phase II study, the efficacy and safety of a topical eutectic mixture for premature ejaculation (TEMPE), a metered-dose aerosol spray containing a eutectic mixture of lidocaine and prilocaine, as a treatment for PE.

Patients And Methods: Men with PE (Diagnostic and Statistical Manual-IV definition) aged 18-75 years were randomized into a double-blind, placebo-controlled study in the UK and the Netherlands. Efficacy variables included the mean change in intravaginal ejaculatory latency time (IELT) from baseline and the proportion of patients who achieved an IELT of > or = 4, > or = 3 or > or = 2 min on two occasions, and the effect of TEMPE on the index of ejaculatory control (IEC) and sexual quality-of-life (SQoL) scores of patients and their partners.

Randomized, placebo-controlled comparison of early use of frovatriptan in a migraine attack versus dosing after the headache has become moderate or severe.

Objective: To evaluate whether frovatriptan would provide greater relief if given early during a migraine attack.

Research Design And Methods: Adults with a history of migraine of at least 1 year, and who had 2-8 headaches in the previous month were recruited from 19 US centres for a prospective, placebo-controlled crossover study over 2 migraine attacks. Dose 1 was taken at the onset of mild migraine headache, Dose 2 was taken at least 2 h later if the headache progressed to moderate/severe.

A randomized trial of frovatriptan for the intermittent prevention of menstrual migraine.

Background: Menstrually associated migraine (MAM) is often prolonged and difficult to manage with conventional therapies. Frovatriptan is a new selective 5HT(1B/1D) receptor agonist indicated for short-term management of migraine. It has a long half-life and good tolerability.

Frovatriptan use in migraineurs with or at high risk of coronary artery disease.

Objective: To investigate the cardiovascular effects of frovatriptan 2.5 mg during a migraine attack in patients with, or at high risk of, coronary artery disease.

Background: Rare occurrences of myocardial ischemia and coronary and peripheral vasospasm associated with the use of sumatriptan have triggered concern over the vasoconstrictor properties of the triptan class of drugs.

Consequences of transforming measures of efficacy for acute therapies: 5-HT agonists as a worked example.

Objectives: To examine whether the distributions of active and placebo response rates change after transformation into therapeutic gains, numbers needed to treat, and therapeutic ratios for 51 published clinical trials of 5-HT(1B/1D) agonists in the acute treatment of migraine.

Background: Acute migraine therapies have been compared using meta-analysis. Before pooling the results of noncontemporaneous clinical trials for meta-analysis, reconciliation of active response rates with concurrent placebo controls is done because of fluctuations in placebo response rates.

Migraine headache recurrence: relationship to clinical, pharmacological, and pharmacokinetic properties of triptans.

Background And Objectives: Triptan use is associated with headache recurrence, and this has been cited as an important reason for patient dissatisfaction with the treatment. The mechanism by which recurrence occurs is not clear, and the incidence of recurrence varies with the triptan used. In order to explore the pharmacological and physiological interaction of triptans and migraine headache recurrence further, some specific clinical, pharmacological, and pharmacokinetic factors that might influence migraine recurrence were evaluated in a review of the major efficacy data for the drugs in the triptan class.

Comparison of therapeutic gain with therapeutic ratio for the assessment of selective 5HT(1B/1D) agonist efficacy in migraine.

Objective: Comparison of use of therapeutic gain (TG) and therapeutic ratio (TR) for relative assessments of selective 5HT(1B/1D) agonist efficacy in the acute treatment of migraine.

Background: Comparison of selective 5HT(1B/1D) agonist efficacy in the acute treatment of migraine is complicated by the impracticality of conducting high-quality head-to-head active comparator trials for all permutations of drug, dose, and route of administration; the clinical trials that are available are usually noncontemporaneous, and have fluctuating active and placebo response rates (ARR and PRR, respectively) for the necessarily subjective endpoints. The standard primary endpoint is conversion of headache score 2 (moderate pain) or score 3 (severe pain) into score 0 (no pain) or score 1 (mild pain) at a single timepoint (usually 2 or 4 hours postdose).

Tolerability and safety of frovatriptan with short- and long-term use for treatment of migraine and in comparison with sumatriptan.

Objective: To evaluate the tolerability and safety of frovatriptan 2.5 mg in patients with migraine.

Background: Frovatriptan is a new, selective serotonin agonist (triptan) developed for the acute treatment of migraine.

Dose range-finding studies with frovatriptan in the acute treatment of migraine.

Objective: To determine the optimum dose of frovatriptan for the acute treatment of migraine.

Background: Frovatriptan is a new triptan developed for the acute treatment of migraine. The dose-response characteristics and safety of frovatriptan have been investigated across a broad range of doses from 0.