Iron therapy supplementation in inflammatory bowel disease patients with iron deficiency anemia: findings from a real-world analysis in Italy.

BACKGROUND: This real-world analysis evaluated iron therapy supplementation in inflammatory bowel disease patients with iron-deficiency anemia, considering disease progression and healthcare resource consumption. METHODS: A retrospective observational study was conducted using administrative databases of a pool of Italian healthcare entities, covering about 9.3 million beneficiaries. Between January 2010 and September 2017, adult patients were enrolled in the presence of either hospitalization or active exemption code for ulcerative colitis/Crohn's disease, or one vedolizumab prescription. Iron-deficiency anemia was identified by at least one prescription for iron and/or hospitalization for iron-deficiency anemia and/or blood transfusion (proxy of diagnosis). Patients were divided in untreated and iron-treated during 12-month follow-up and analyzed before and after propensity score matching. Disease progression, was evaluated through inflammatory bowel disease-related hospitalizations and surgeries, and healthcare resource utilization was assessed. RESULTS: Overall, 1753 patients were included, 1077 (61.4%) treated with iron therapy and 676 (38.6%) untreated. After propensity score matching, 655 patients were included in each group. In unbalanced cohorts, disease progression was significantly reduced in patients receiving iron therapy compared to the untreated (11.0% vs. 15.7%, P  < 0.01), and this trend was maintained also after applying propensity score matching. The overall mean cost/patient was significantly lower in iron-treated than untreated (4643€ vs. 6391€, P  < 0.01). CONCLUSION: The findings of this real-world analysis suggest that iron therapy was associated with significant benefits in inflammatory bowel disease patients with iron-deficiency anemia, in terms of both disease progression and healthcare resource utilization.

Impact of micronutrients and nutraceuticals on cognitive function and performance in Alzheimer's disease.

Alzheimer's disease (AD) is a major global health problem today and is the most common form of dementia. AD is characterized by the formation of ß-amyloid (Aß) plaques and neurofibrillary clusters, leading to decreased brain acetylcholine levels in the brain. Another mechanism underlying the pathogenesis of AD is the abnormal phosphorylation of tau protein that accumulates at the level of neurofibrillary aggregates, and the areas most affected by this pathological process are usually the cholinergic neurons in cortical, subcortical, and hippocampal areas. These effects result in decreased cognitive function, brain atrophy, and neuronal death. Malnutrition and weight loss are the most frequent manifestations of AD, and these are also associated with greater cognitive decline. Several studies have confirmed that a balanced low-calorie diet and proper nutritional intake may be considered important factors in counteracting or slowing the progression of AD, whereas a high-fat or hypercholesterolemic diet predisposes to an increased risk of developing AD. Especially, fruits, vegetables, antioxidants, vitamins, polyunsaturated fatty acids, and micronutrients supplementation exert positive effects on aging-related changes in the brain due to their antioxidant, anti-inflammatory, and radical scavenging properties. The purpose of this review is to summarize some possible nutritional factors that may contribute to the progression or prevention of AD, understand the role that nutrition plays in the formation of Aß plaques typical of this neurodegenerative disease, to identify some potential therapeutic strategies that may involve some natural compounds, in delaying the progression of the disease.

The Effects of Andrographis paniculata (Burm.F.) Wall. Ex Nees and Andrographolide on Neuroinflammation in the Treatment of Neurodegenerative Diseases.

Neurodegenerative diseases (NDs) affect millions of people worldwide, and to date, Alzheimer's and Parkinson's diseases are the most common NDs. Of the many risk factors for neurodegeneration, the aging process has the most significant impact, to the extent that it is tempting to consider neurodegenerative disease as a manifestation of accelerated aging. However, genetic and environmental factors determine the course of neurodegenerative disease progression. It has been proposed that environmental stimuli influence neuroplasticity. Some clinical studies have shown that healthy lifestyles and the administration of nutraceuticals containing bioactive molecules possessing antioxidant and anti-inflammatory properties have a preventive impact or mitigate symptoms in previously diagnosed patients. Despite ongoing research efforts, the therapies currently used for the treatment of NDs provide only marginal therapeutic benefits; therefore, the focus is now directly on the search for natural products that could be valuable tools in combating these diseases, including the natural compound Andrographis paniculata (Ap) and its main constituent, andrographolide (Andro). Preclinical studies have shown that the aqueous extract of Ap can modulate neuroinflammatory and neurodegenerative responses, reducing inflammatory markers and oxidative stress in various NDs. Therefore, in this review, we will focus on the molecular mechanisms by which Ap and Andro can modulate the processes of neurodegeneration and neuroinflammation, which are significant causes of neuronal death and cognitive decline.

Liraglutide chronic treatment prevents development of tolerance to antiseizure effects of diazepam in genetically epilepsy prone rats.

Glucagon-like peptide-1 (GLP-1) is a hormone that can regulate several neuronal functions. The modulation of GLP-1 receptors emerged as a potential target to treat several neurological diseases, such as epilepsy. Here, we studied the effects of acute and chronic treatment with liraglutide (LIRA), in genetically epilepsy prone rats (GEPR-9s). We have also investigated the possible development of tolerance to antiseizure effects of diazepam, and how LIRA could affect this phenomenon over the same period of treatment. The present data indicate that an acute treatment with LIRA did not diminish the severity score of audiogenic seizures (AGS) in GEPR-9s. By contrast, a chronic treatment with LIRA has shown only a modest antiseizure effect that was maintained until the end of treatment, in GEPR-9s. Not surprisingly, acute administration of diazepam reduced, in a dose dependent manner, the severity of the AGS in GEPR-9s. However, when diazepam was chronically administered, an evident development of tolerance to its antiseizure effects was detected. Interestingly, following an add-on treatment with LIRA, a reduced development of tolerance and an enhanced diazepam antiseizure effect was observed in GEPR-9s. Overall, an add-on therapy with LIRA demonstrate benefits superior to single antiseizure medications and could be utilized to treat epilepsy as well as associated issues. Therefore, the potential use of GLP1 analogs for the treatment of epilepsy in combination with existing antiseizure medications could thus add a new and long-awaited dimension to its management.

Oxygen-Ozone Therapy in Cervicobrachial Pain: A Real-Life Experience.

This prospective, open-label clinical study was carried out to evaluate both the efficacy and safety of intramuscular paravertebral injections of an oxygen−ozone (O2−O3) mixture in patients with cervicobrachial pain. We enrolled 540 subjects affected by cervicobrachial pain referred to the Ozone Therapy Ambulatory at the Mater Domini Hospital of Catanzaro (Italy) and to the Center of Pain in Taurianova (Reggio Calabria, Italy). All the subjects (n = 540) completed the treatment and the follow-up visits. The subjects received a mean of 11 cervical intramuscular treatments with an O2−O3 mixture (5 mL) with an O3 concentration of 10 µg/mL bis a week. The improvement of pain was measured by a change in the mean of the Visual Analog Scale (VAS) score from baseline to the end of treatment and during follow-ups. Patient satisfaction was assessed at the end of treatment using the SF-36 Questionnaire. The development of adverse drug reactions was recorded. The mean (±standard deviation) VAS pain score at baseline, at the end of treatment, and during follow-ups showed a significant reduction in pain over time (p < 0.001). All the patients who were enrolled (n: 540) were pain-free after one year. According to the pain distribution, all subjects showed a significant reduction in pain over time in each group (p < 0.05). No significant differences were observed with respect to sex or age. No adverse events were observed during the study. In conclusion, we documented that the intramuscular injection of an O2−O3 mixture is an effective and safe treatment option for patients with cervicobrachial pain.

Implementing a simple pharmacovigilance program to improve reporting of adverse events associated with biologic therapy in rheumatology: Preliminary results from the Calabria Biologics Pharmacovigilance Program (CBPP).

INTRODUCTION: Post-marketing surveillance activities (namely pharmacovigilance) are crucial to favor the early detection of unexpected adverse events (AEs) and/or serious adverse reactions (SAEs). Indeed, spontaneous reporting of AEs has been demonstrated to underestimate the number of events in different clinical settings. Aim of the present study is to report the preliminary data of a Regional (Calabria, Italy) Pharmacovigilance Program (CBPP) aimed at improving AEs' reporting associated with biologics use in rheumatology. MATERIALS AND METHODS: We developed a simple, cost-effective pharmacovigilance program based on regular training sessions for physicians (stimulated reporting), periodical phone calls by a clinical pharmacologist aimed at identifying new events and stimulating self-awareness and encouraging reporting to the physician during the subsequent follow-up visit for minor AEs. To test this approach, all consecutive patients undergoing treatment with one biologic agent at eight rheumatology centers during a two-years period were invited to participate. Collected AEs were compared to the number of AEs spontaneously reported for the same molecules in the same centers before starting the protocol. RESULTS: During the study period, 399 patients (245 females; mean age: 58 ± 11 years) were started on treatment with biologics for active RA (n = 211, 52.9%), PsA (n = 119, 29.8%) or AS (n = 69, 17.3%) at eight rheumatology centers. A total of 125 AEs (31.3%) and 9 SAEs (2.3%) were reported during the two-years study period. In the control cohort (comprising 368 consecutive patients started on treatment with bDMARDs during a two-years period before CBPP study) only 42 (11.4%) AEs and no SAEs were reported (p < 0.0001). The most common AEs were injection site reactions and skin disorders. CONCLUSIONS: In conclusion, our study provides further evidence of a critical role of active pharmacovigilance in detection, reporting and analysis of AEs in rheumatology.

Perampanel chronic treatment does not induce tolerance and decreases tolerance to clobazam in genetically epilepsy prone rats.

Tolerance to some therapeutic effects of antiepileptic drugs may account for the development of pharmacoresistance in patients with epilepsy. In the present study, following oral acute pretreatment with the new antiepileptic drug perampanel (0.1, 0.3, 1 or 3 mg/kg), we observed that the drug significantly and dose-dependently attenuated the seizure phases (clonus and tonus) of audiogenic seizures in genetically epilepsy prone rats (GEPR-9 s), a genetic model of reflex generalized epilepsy. In addition, the GEPR-9 s were administered orally with perampanel (1 or 3 mg/kg) once daily for 10 weeks in order to study the possible development of tolerance, and when animals were subjected to auditory stimulation we observed that the ED50 values against clonus or tonus were not significantly different from those observed after single administration. Furthermore, the duration of anticonvulsant effects observed between 60 min and 9 h following oral administration of perampanel (1 mg/kg) were similar in acute and after chronic treatment. In another group of experiments, clobazam (0.75, 1.5, 3, 6, 9, 12 and 15 mg/kg) after acute administration was able to dose-dependently reduce the severity of the audiogenic seizures in GEPR-9 s. When clobazam (6 or 12 mg/kg) was administered alone for 10 consecutive weeks a clear development of tolerance to its anticonvulsant effects within approximately seven weeks was observed. In addition, we observed that when clobazam (6 mg/kg) was co-administered with perampanel (1 mg/kg), the latter drug was able to attenuate the development of tolerance to the antiseizure activity of clobazam. The present data indicate that both perampanel and clobazam are effective against audiogenic seizures, however, clobazam effects are hampered by the development of tolerance. Furthermore, concomitant treatment with perampanel slows development of tolerance to the anticonvulsant effects of clobazam in GEPR-9 s.

The potential role of cannabinoids in epilepsy treatment.

INTRODUCTION: Epilepsy is one of the world's oldest recognized and prevalent neurological diseases. It has a great negative impact on patients' quality of life (QOL) as a consequence of treatment resistant seizures in about 30% of patients together with drugs' side effects and comorbidities. Therefore, new drugs are needed and cannabinoids, above all cannabidiol, have recently gathered attention. Areas covered: This review summarizes the scientific data from human and animal studies on the major cannabinoids which have been of interest in the treatment of epilepsy, including drugs acting on the endocannabinoid system. Expert commentary: Despite the fact that cannabis has been used for many purposes over 4 millennia, the development of drugs based on cannabinoids has been very slow. Only recently, research has focused on their potential effects and CBD is the first treatment of this group with clinical evidence of efficacy in children with Dravet syndrome; moreover, other studies are currently ongoing to confirm its effectiveness in patients with epilepsy. On the other hand, it will be of interest to understand whether drugs acting on the endocannabinoid system will be able to reach the market and prove their known preclinical efficacy also in patients with epilepsy.

From Cannabis to Cannabidiol to Treat Epilepsy, Where Are We?

BACKGROUND: Several antiepileptic drugs (AEDs), about 25, are currently clinically available for the treatment of patients with epilepsy. Despite this armamentarium and the many recently introduced AEDs, no major advances have been achieved considering the number of drug resistant patients, while many benefits have been indeed obtained for other clinical outcomes (e.g. better tolerability, less interactions). Cannabinoids have long been studied for their potential therapeutical use and more recently phytocannabinoids have been considered a valuable tool for the treatment of several neurological disorders including epilepsy. Among this wide class, the most studied is cannabidiol (CBD) considering its lack of psychotropic effects and its anticonvulsant properties. OBJECTIVE: Analyse the currently available literature on CBD also in light of other data on phytocannabinoids, reviewing data spanning from the mechanism of action, pharmacokinetic to clinical evidences. RESULTS: Several preclinical studies have tried to understand the mechanism of action of CBD, which still remains largely not understood. CBD has shown significant anticonvulsant effects mainly in acute animal models of seizures; beneficial effects were reported also in animal models of epileptogenesis and chronic models of epilepsy, although not substantial. In contrast, data coming from some studies raise questions on the effects of other cannabinoids and above all marijuana. CONCLUSION: There is indeed sufficient supporting data for clinical development and important antiepileptic effects and the currently ongoing clinical studies will permit the real usefulness of CBD and possibly other cannabinoids. Undoubtedly, several issues also need to be addressed in the next future (e.g. better pharmacokinetic profiling). Finally, shading light on the mechanism of action and the study of other cannabinoids might represent an advantage for future developments.

The Anticonvulsant Activity of a Flavonoid-Rich Extract from Orange Juice Involves both NMDA and GABA-Benzodiazepine Receptor Complexes.

The usage of dietary supplements and other natural products to treat neurological diseases has been growing over time, and accumulating evidence suggests that flavonoids possess anticonvulsant properties. The aim of this study was to examine the effects of a flavonoid-rich extract from orange juice (OJe) in some rodent models of epilepsy and to explore its possible mechanism of action. The genetically audiogenic seizures (AGS)-susceptible DBA/2 mouse, the pentylenetetrazole (PTZ)-induced seizures in ICR-CD1 mice and the WAG/Rij rat as a genetic model of absence epilepsy with comorbidity of depression were used. Our results demonstrate that OJe was able to exert anticonvulsant effects on AGS-sensible DBA/2 mice and to inhibit PTZ-induced tonic seizures, increasing their latency. Conversely, it did not have anti-absence effects on WAG/Rij rats. Our experimental findings suggest that the anti-convulsant effects of OJe are likely mediated by both an inhibition of NMDA receptors at the glycine-binding site and an agonistic activity on benzodiazepine-binding site at GABAA receptors. This study provides evidences for the antiepileptic activity of OJe, and its results could be used as scientific basis for further researches aimed to develop novel complementary therapy for the treatment of epilepsy in a context of a multitarget pharmacological strategy.

When Nutraceuticals Reinforce Drugs Side Effects: A Case Report.

INTRODUCTION: Nutraceutical is a term applied for a plethora of products ranging from isolated nutrients, herbal products to dietary supplements and recently, the interest for a nutraceutical approach to lipid and metabolic disorders is growing. Patients with metabolic conditions seem to appreciate a therapeutic management that does not involve drug treatment, particularly for the side effects due to statins, a class of drug used for lipid disorders. Statins directly induce skeletal muscle injury and in the elderly patients, under polytherapy treatments, this risk relies to an increase in adverse drug reactions due to drug interactions. CASE DESCRIPTION: Herein we report a 70-year-old woman under polytherapy who developed rhabdomyolysis after starting the administration of a dietary supplement containing monacolin K. Using the Drug Interaction Probability Scale, we postulated that rhabdomyolysis was possibly related to a drug interaction between sertraline, rosuvastatin and monacolin K. These treatments were discontinued leading to a remission of both clinical symptoms and biochemical parameters. CONCLUSION: This case report highlights how pharmacological treatment must be periodically reassessed, since elderly people could take drugs by themselves when they donot need.

CB1 agonists, locally applied to the cortico-thalamic circuit of rats with genetic absence epilepsy, reduce epileptic manifestations.

Drugs that modulate the endocannabinoid system and endocannabinoids typically play an anticonvulsant role although some proconvulsant effects have been reported both in humans and animal models. Moreover, no evidence for a role of the cannabinoid system in human absence epilepsy has been found although limited evidence of efficacy in relevant experimental animal models has been documented. This study aims to characterize the role of cannabinoids in specific areas of the cortico-thalamic network involved in oscillations that underlie seizures in a genetic animal model of absence epilepsy, the WAG/Rij rat. We assessed the effects of focal injection of the endogenous cannabinoid, anandamide (AEA), a non-selective CB receptor agonist (WIN55,212) and a selective CB1 receptor antagonist/inverse agonist (SR141716A) into thalamic nuclei and primary somatosensory cortex (S1po) of the cortico-thalamic network. AEA and WIN both reduced absence seizures independently from the brain focal site of infusion while, conversely, rimonabant increased absence seizures but only when focally administered to the ventroposteromedial thalamic nucleus (VPM). These results, together with previous reports, support therapeutic potential for endocannabinoid system modulators in absence epilepsy and highlight that attenuated endocannabinergic function may contribute to the generation and maintenance of seizures. Furthermore, the entire cortico-thalamic network responds to cannabinoid treatment, indicating that in all areas considered, CB receptor activation inhibits the pathological synchronization that subserves absence seizures. In conclusion, our result might be useful for the identification of future drug therapies in absence epilepsy.

New AMPA antagonists in epilepsy.

INTRODUCTION: Epilepsy is a common neurological disorder; however, its therapy is not satisfactory because a large number of patients suffer from refractory seizures and/or has a low quality of life due to antiepileptic drug (AED) side effects. Glutamate is the major excitatory neurotransmitter in the brain, AMPA receptors (AMPARs) represent a validated target for AEDs' development. Evidences support their role during seizures and neurodegeneration. Development of AMPAR ligands has led to two different branches of research, with the identification of competitive and noncompetitive antagonists. AREAS COVERED: We herein describe the architecture of AMPAR and the main structure-activity relationships of antagonists. Finally, we report the effects of AMPAR antagonists in preclinical models and clinical trials in epileptic patients. We reviewed the most relevant research in the field, focusing on research advances for the oldest AMPA antagonists and the new most promising molecules identified. EXPERT OPINION: Overall, the development of AMPAR antagonists confirms their great clinical potential; their arrival to clinical practice has been slowed down by their unfavorable pharmacokinetic profile and tolerability; however, their clinical use might be justified by their efficacy and the new drugs developed such as perampanel have been greatly ameliorated from both points of view.

Preclinical activity profile of α-lactoalbumin, a whey protein rich in tryptophan, in rodent models of seizures and epilepsy.

PURPOSE: To evaluate the potential anticonvulsant activity of α-lactalbumin (ALAC), a whey protein rich in tryptophan (TRP) relative to other large neutral amino acids (LNAAs), in rodent models of seizures and epilepsy. METHODS: The effects of ALAC administered per os were evaluated by standard protocols against audiogenic seizures in Genetic Epilepsy Prone Rats (GEPR-9 rats), maximal electroshock (MES)-induced seizures in rats, pilocarpine-induced seizures in mice, spontaneous chronic seizures in mice exposed to pilocarpine-induced status epilepticus (SE), and absence seizures in WAG/Rij rats. In some models, carbamazepine (CBZ) was included as an active control. Plasma TRP/LNAAs ratios were measured by GC-MS. RESULTS: Single doses of ALAC up to 500 or 6000 mg/kg were devoid of anticonvulsant activity in all models tested. Conversely, 5- and 12-day treatment with ALAC (250-1000 mg/kg/day) in GEPR rats reduced dose-dependently seizure scores and prolonged latency to clonus onset, with full persistence of the effect for up to 12h. ALAC (125-500 mg/kg/day for 15 days) protected against seizures induced by 250 mg/kg pilocarpine, but was less effective against higher pilocarpine doses. Similarly to CBZ, ALAC (125-500 mg/kg/day for 15 days) was also effective against spontaneous seizures in the post-pilocarpine SE model. ALAC (up to 6000 mg/kg/day for 12 days) did not prevent MES-induced seizures, although it reduced the duration of tonic extension at doses between 250 and 1000 mg/kg/day. Absence seizures in WAG/Rij rats were not significantly affected by ALAC. Plasma TRP/LNAAS ratios increased 2- to 3-fold after dosing with ALAC (250 mg/kg/day) for 7 and 14 days, respectively. CONCLUSIONS: ALAC exerts significant protective activity against seizures in animal models, the effect being especially prominent against audiogenic seizures in GEPR-9 rats, seizures induced by low-dose pilocarpine in mice, and spontaneous seizures in mice exposed to pilocarpine-induced SE. This action is likely to be mediated by increased availability of TRP in the brain, with a consequent increase in 5-HT mediated transmission.

Altered distribution and function of A2A adenosine receptors in the brain of WAG/Rij rats with genetic absence epilepsy, before and after appearance of the disease.

The involvement of excitatory adenosine A(2A) receptors (A(2A)Rs), which probably contribute to the pathophysiology of convulsive seizures, has never been investigated in absence epilepsy. Here, we examined the distribution and function of A(2A)Rs in the brain of Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats, a model of human absence epilepsy in which disease onset occurs 2-3 months after birth. In the cerebral areas that are mostly involved in the generation of absence seizures (somatosensory cortex, reticular and ventrobasal thalamic nuclei), A(2A)R density was lower in presymptomatic WAG/Rij rats than in control rats, as evaluated by immunohistochemistry and western blotting. Accordingly, in cortical/thalamic slices prepared from the brain of these rats, A(2A)R stimulation with the agonist 2-[4-(-2-carboxyethyl)-phenylamino]-5'-N-ethylcarboxamido-adenosine failed to modulate either cAMP formation, mitogen-activated protein kinase system, or K(+)-evoked glutamate release. In contrast, A(2A)R expression, signalling and function were significantly enhanced in brain slices from epileptic WAG/Rij rats as compared with matched control animals. Additionally, the in vivo injection of the A(2A)R agonist CGS21680, or the antagonist 5-amino-7-(2-phenylethyl)-2-(2-fuyl)-pyrazolo-(4,3-c)1,2,4-triazolo(1,5-c)-pyrimidine, in the examined brain areas of epileptic rats, increased and decreased, respectively, the number/duration of recorded spontaneous spike-wave discharges in a dose-dependent manner during a 1-5 h post-treatment period. Our results support the hypothesis that alteration of excitatory A(2A)R is involved in the pathogenesis of absence seizures and might represent a new interesting target for the therapeutic management of this disease.

Novel potent anticonvulsant agent containing a tetrahydroisoquinoline skeleton.

In our studies on the development of new anticonvulsants, we planned the synthesis of N-substituted 1,2,3,4-tetrahydroisoquinolines to explore the structure-activity relationships. All derivatives were evaluated against audiogenic seizures in DBA/2 mice, and the 1-(4'-bromophenyl)-6,7-dimethoxy-2-(piperidin-1-ylacetyl) derivative (26) showed the highest activity with a potency comparable to that of talampanel, the only noncompetitive alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) antagonist in clinical trials as an anticonvulsant agent. Electrophysiological experiments indicated that 26 acts as noncompetitive AMPA receptor modulator.

3D pharmacophore models for 1,2,3,4-tetrahydroisoquinoline derivatives acting as anticonvulsant agents.

A 3D pharmacophore model predicting anticonvulsant activity was obtained for a series of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline derivatives recently disclosed as a new class of noncompetitive AMPA receptor antagonists. The training set included 17 compounds with varying potency against audiogenic seizures in DBA/2 mice. The best statistical hypothesis, generated with the HypoGen module of Catalyst 4.9, consisted of five features: two hydrogen bond acceptors, two hydrophobic features, and one hydrophobic aromatic region, providing a model with a correlation coefficient of 0.919. The obtained model was an efficient tool in the design of some new anticonvulsant agents containing the tetrahydroisoquinoline scaffold. Moreover, in order to explain the different degree of efficacy of the newly designed N-substituted derivatives, excluded volumes were also considered.

Nifedipine affects the anticonvulsant activity of topiramate in various animal models of epilepsy.

Topiramate (TPM), a new generation antiepileptic drug was investigated for its anticonvulsant effects in various models of genetically determined and chemically induced epilepsy in rodents. In addition, based on recent electrophysiological data suggesting that TPM may interact with L-type Ca(2+) channels, we evaluated the effects of a concomitant administration of L-type Ca(2+) channel modulators on TPM's antiepileptic properties. TPM, dose-dependently, protected against audiogenic seizures in DBA/2 mice. Concomitant treatment with TPM and a low dose of L-type Ca(2+) channel antagonists nifedipine or verapamil or with the L-type Ca(2+) channel agonist, S(-)-1,4-dihydro-2,6-dimethyl-5-nitro-4-[2-(trifluoromethyl)phenyl]-3-pyridinecarboxylic acid methyl ester (Bay k 8644) was able to increase the ED(50) for this drug. TPM also protected against seizures induced by alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), 4-aminopyridine (4-AP) and pentylenetetrazole (PTZ), but this activity was not significantly modified by nifedipine. TPM, dose-dependently, reduced the number and duration of epileptic spike-wave discharges (SWDs) both in WAG/Rij rats and lethargic (lh/lh) mice, two genetic models of absence epilepsy. Nifedipine decreased TPM's activity in WAG/Rij rats but paradoxically enhanced it in lh/lh mice, whereas Bay k 8644 displayed opposite effects in both absence models. These results confirm TPM's broad spectrum of anticonvulsant activity and support the proposal that a modulation of neuronal L-type Ca(2+) channel activity plays an important role in its antiepileptic activity.