DSP-4 induced depletion of brain noradrenaline and increased 6-hertz psychomotor seizure susceptibility in mice is prevented by sodium valproate.

The central neurotransmitters assume a noteworthy part in the pathophysiology of epilepsy, noradrenaline is one of them. However, its role in 6 Hz induced psychomotor seizures is not known. The present study was, therefore, designed to investigate the role of noradrenaline (NA) in 6 Hz-induced psychomotor seizures in Swiss albino mice using N-2-Chloroethyl-N-ethyl-2-bromobenzylamine hydrochloride (DSP-4), a well-known depletor of NA. The vehicle and DSP-4 treated mice were given 6 Hz stimulation. A sham treatment was utilized as a comparator and sodium valproate (SVP) was utilized as a reference anti-epileptic medication. Behavioral changes instigated by 6 Hz stimulation were described as the increased duration of Straub's tail, stun position, twitching of vibrissae, forelimb clonus and increased rearing and grooming. DSP-4 administration further amplified the seizures and behavioral changes while pretreatment with SVP reduced the same in mice. Further, SVP pre-treatment also attenuated the ultra-structural changes observed in cortex and hippocampus of mice treated with DSP-4 and 6 Hz. Finally, the neurochemical estimation of NA in cortex and hippocampus confirmed the depletion of NA following DSP-4 and 6 Hz seizures. SVP pretreatment (but not post-treatment) protected the mice from 6 Hz seizures and attenuated the DSP-4 induced alterations of nor-adrenaline content in the mouse brain. The study indicates low brain NA content to enhance pharmacoresistant seizures in mice and demonstrates that SVP mediated protection against 6 Hz results possibly via modulation of NA content.

Parachlorophenylalanine-induced 5-HT depletion alters behavioral and brain neurotransmitters levels in 6-Hz psychomotor seizure model in mice.

The present study was designed to investigate the role of serotonin and other neurotransmitters namely dopamine (DA), histamine, nor-epinephrine (NE), glutamate, and γ-aminobutyric acid (GABA) in the 6-Hz-induced psychomotor seizures in Swiss albino mice. Parachlorophenylalanine (PCPA, 300 mg/kg/day, i.p for 3 days)-treated mice were given 6-Hz stimulation. Sodium valproate (SVP) (200 mg/kg/day, p.o for 3 days) was used as a reference antiepileptic drug. The behavioral changes induced by 6 Hz including increased rearing and grooming, Straub's tail, behavioral arrest, stun position were amplified by PCPA. The 6-Hz-induced seizures were accompanied by reduced brain 5-HT, DA, NE, histamine, GABA, and enhanced glutamate levels. PCPA facilitated further reduction of endogenous 5-HT and DA levels but not NE, histamine, GABA, and glutamate levels. Pre- and post-treatment with SVP protected the mice from 6-Hz seizures and attenuated PCPA-induced changes in the levels of 5-HT and DA in the mice brain suggesting the protective effect of SVP in the pharmacoresistant model of epilepsy involving mainly serotonergic mechanism. However, the study also suggests modulation of other neurotransmitters both in 6-Hz psychomotor seizures and in the action of SVP against such seizures.

Characterization of a lamotrigine-resistant kindled model of epilepsy in mice: evaluation of drug resistance mechanisms.

The aims of this study were to characterize a lamotrigine-resistant kindled model of epilepsy in mice, to study the anticonvulsant effect of carbamazepine (CBZ) and valproic acid (VPA), and to probe into the mechanism for resistance. Swiss albino mice were kindled by a subconvulsive dose of pentylenetetrazole (PTZ, 30 mg/kg, i.p., every other day for 6 weeks). The mice were pre-treated (30 min.) either with a low dose of LTG (5 mg/kg, i.p.) or with vehicle, and the seizures were scored. The acute treatment with LTG (15 mg/kg, i.p.) on the last day blocked seizure in the vehicle-treated group, but the LTG pre-treated group showed resistance. This resistance was extended to CBZ, but not to VPA. The resistant model was successfully replicated in mice with less kindling development time (6 weeks versus 9 weeks 5 days in rats). A highly significant decrease in the level of histamine (p < 0.001) was found, and there were also decreases in serotonin, GABA and AChE levels (p < 0.05). A significantly low level of histamine correlates with drug resistance and indicates involvement of the H1/H3 receptors. It is suggested that the selective action on voltage-gated Na(+) and Ca(2+) channels could explain the differences in the sensitivity of CBZ and VPA.

Tulsi oil as a potential penetration enhancer for celecoxib transdermal gel formulations.

The focus of the present study was to develop and evaluate the transdermal system of celecoxib. Transdermal gels composed of carbopol 940 in propylene glycol (PG) containing penetration enhancers. The formulations were characterized by permeation, pharmacokinetics, pharmacodynamics and histopathology. Celecoxib permeation across excised rat skins were statistically (p < 0.05) enhanced by tulsi oil compared to turpentine oil containing formulations. In comparison to orally administered formulations, the pharmacokinetic parameters of gel and control formulations were significantly higher (p < 0.05). The maximum plasma concentration (Cmax) obtained with formulations containing 4% turpentine and 6% tulsi oil was, respectively, 1.52 and 2.41 times higher than the formulations without penetration enhancer. Similarly, area under the curve (AUC) of these formulations was 1.70 and 2.40 times higher than the formulations without penetration enhancers. Anti-inflammatory studies demonstrated a statistically significant (p < 0.05) pharmacodynamics profile for the transdermal gel formulations compared to orally administered and control celecoxib formulations. Histopathological studies revealed some disruption in the epidermis without any toxic effect on the dermis layer of skin by penetration enhancers. In summary, the transdermal gel formulations of celecoxib containing penetration enhancers sustained drug level in the blood and will reduce the dose frequency as required with its conventional oral formulation.

Aliskiren alleviates doxorubicin-induced nephrotoxicity by inhibiting oxidative stress and podocyte injury.

INTRODUCTION: Doxorubicin (DXR) is one of the most effective and widely used anthracycline antibiotics. However, its clinical application is hampered by toxic effects in many organs. Nephrotoxicity is one of the major side effects of anthracycline antibiotics. This study was designed to investigate the possible protective effects of aliskiren (a direct renin inhibitor) in DXR-induced nephrotoxicity in rats. MATERIALS AND METHODS: Wistar albino rats were intraperitoneally (ip) injected with DXR and renin activity, albumin, total protein, urea, creatinine levels in plasma and ultrastructural changes in podocytes were assessed. RESULTS: Rats subjected to DXR administration had significant (p<0.01) increases in systolic blood pressure, plasma renin activity, plasma concentration of urea, creatinine and tissue malondialdehyde and significant (p<0.01) reductions in plasma concentrations of albumin, total protein and antioxidant defense (reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT)) in renal tissues. Furthermore, DXR-induced nephrotoxicity has also been characterized by broadening of podocyte foot processes, enlargement of glomerular basement membrane width and reduction in slit pore diameter. The above effects of DXR were significantly (p<0.01) prevented by aliskiren treatment. CONCLUSIONS: These findings revealed that the blockade of renin activity by aliskiren is a promising approach in the treatment of DXR-induced nephrotoxicity.

Monitoring of adverse drug reactions associated with antihypertensive medicines at a university teaching hospital in New Delhi.

AIM: To monitor the adverse drug reactions (ADRs) caused by antihypertensive medicines prescribed in a university teaching hospital. METHODS: The present work was an open, non-comparative, observational study conducted on hypertensive patients attending the Medicine OPD of Majeedia Hospital, Jamia Hamdard, New Delhi, India by conducting patient interviews and recording the data on ADR monitoring form as recommended by Central Drugs Standard Control Organization (CDSCO), Government of India. RESULTS: A total of 21 adverse drug reactions were observed in 192 hypertensive patients. Incidence of adverse drug reactions was found to be higher in patients more than 40 years in age, and females experienced more ADRs (n = 14, 7.29%) than males, 7 (3.64%). Combination therapy was associated with more number of adverse drug reactions (66.7%) as against monotherapy (33.3%). Calcium channel blockers were found to be the most frequently associated drugs with adverse drug reactions (n = 7), followed by diuretics (n = 5), and ß-blockers (n = 4). Among individual drugs, amlodipine was found to be the commonest drug associated with adverse drug reactions (n = 7), followed by torasemide (n = 3). Adverse drug reactions associated with central nervous system were found to be the most frequent (42.8%) followed by musculo-skeletal complaints (23.8%) and gastro-intestinal disorders (14.3%). CONCLUSIONS: The present pharmacovigilance study represents the adverse drug reaction profile of the antihypertensive medicines prescribed in our university teaching hospital. The above findings would be useful for physicians in rational prescribing. Calcium channel blockers were found to be the most frequently associated drugs with adverse drug reactions.

Effect of alprazolam on anxiety and cardiomyopathy induced by doxorubicin in mice.

Anxiety following heart failure (HF) and/or myocardial infarction (MI) can impede recovery and constitute a major risk factor for further cardiac events. The present study was aimed to evaluate anxiety following doxorubicin (DOX)-induced cardiomyopathy, a rodent model for HF, in mice. Furthermore, the study investigated the effect of alprazolam on anxiety and cardiomyopathy in this model. The study was carried out in Swiss albino mice. DOX was used at a dose of 10 mg/kg i.v. Alprazolam was administered at doses of 0.5, 1 and 2 mg/kg po for 7 days' pre- and 7 days' post-DOX. Anxiety was measured on day 8 and on day 14 using elevated plus maze and Vogel's conflict test. On 14th day, serum lactate dehydrogenase (LDH) was estimated. The mice were then killed and hearts were dissected out for estimation of thiobarbituric acid reactive substance and Transmission Electron Microscopy (TEM) studies. Our results showed that DOX administration induced cardiomyopathy in mice. This was evidenced by an increased serum LDH and tissue malondialdehyde (MDA) and was confirmed by TEM studies. Alprazolam treatment for 14 days dose dependently reversed DOX-induced increase in LDH and MDA as well as the morphological alterations induced by DOX in TEM studies. Furthermore, alprazolam also reversed the anxiety-like effects induced by DOX in both the tests for anxiety. Thus, alprazolam appears to be a good candidate for alleviating anxiety in patients following MI or HF.

Protective effects of aliskiren in doxorubicin-induced acute cardiomyopathy in rats.

In this study, effect of aliskiren (ALK) on doxorubicin (DXR)-induced cardiomyopathy in rats was evaluated. ALK (50 and 100 mg/kg/day) was administered for 7 days and a single intraperitoneal injection of DXR (20 mg/kg) on day 5. The animals were sacrificed 48 h after DXR administration. DXR produced significant elevation in malondialdehyde (MDA) and significantly inhibited the activity of glutathione (GSH) in heart tissue, with a significant rise in the serum levels of lactate dehydrogenase (LDH), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) and reduction in high-density lipoprotein (HDL), indicating acute cardiac toxicity. ALK pretreatment significantly reduced the MDA concentration and ameliorated the inhibition of cardiac GSH activity. ALK also significantly improved the serum levels of LDH, TC, TG, LDL and reduction in HDL in DXR-treated rats. Furthermore, histological examination of the heart sections confirmed the myocardial injury with DXR administration and the near-normal pattern with ALK pretreatment. The results provide clear evidence that the ALK pretreatment offered significant protection against DXR-induced enzymatic changes and cardiac tissue damage.

Bisphosphonates in phenytoin-induced bone disorder.

Chronic administration of phenytoin (PHT) has been associated with bone loss. Bisphosphonates [alendronate (ALD), ibandronate (IBD) and risedronate (RSD)] are potential candidates to prevent PHT-induced bone disorders, and the present study evaluated their effect on the antiepileptic efficacy of PHT. The PHT-induced depletion in folic acid (FA), vitamin B6 and vitamin B12 results in hyperhomocysteinemia. The elevated circulating homocysteine (hcy) could be a risk indicator for micronutrient-deficiency-related osteoporosis via generation of free radicals. Thus, an attempt was also made to unravel the PHT's and bisphosphonates' effect on hcy. Male mice received PHT (35 mg/kg, p.o.) for 90 days to induce bone loss. ALD, RSD and IBD were administered orally at doses 0.65 mg/kg, 0.33 mg/kg, and 0.17 mg/kg respectively, for prevention and 1.3mg/kg, 0.65 mg/kg, and 0.33 mg/kg respectively, for treatment of PHT-induced bone loss. The bone loss was confirmed by bone mineral density (BMD) analysis and bone turnover markers. Serum levels of hcy and FA were estimated along with hydrogen peroxide levels and total antioxidant capacity in order to assess the antioxidant profile of bisphosphonates. The induction of bone loss by PHT was marked by lowered BMD and altered bone turnovers. ALD and RSD administration to PHT treated groups significantly reverted the bony adverse effects. No such effects were observed with IBD. In the bisphosphonates treated groups, hcy levels were statistically at par with the control group. PHT at 35 mg/kg, p.o. could compromise bone mass and thus, could be a model of bone demineralization in mice. The ALD, IBD and RSD have no pharmacodynamic interaction when administered along with PHT at the experimental level. Thus, their usage in the management of PHT-induced bone disease could be worthwhile if clinically approved.

Insights into liaison between antiepileptic drugs and bone.

The adverse effect on bone caused by chronic anticonvulsant therapy causes multiple abnormalities in calcium and bone metabolism, varying from bone turnover, without significant loss of cortical or trabecular bone, to osteopenia/osteoporosis and to osteomalacic disorder. The studies conducted to date have documented anticonvulsant bone disease as a state of increased bone remodeling. With the newer antiepileptic drugs (AEDs) gaining importance and starting to replace conventional medicines, it may be appropriate to compare them with the conventional AEDs and to examine their impact on multiple aspects of bone health. This review focuses on the status of the bony effects of AEDs.

Mechanism of in vitro percutaneous absorption enhancement of carvedilol by penetration enhancers.

The effect of penetration enhancers like tulsi (basil) oil, eucalyptus oil, clove oil, black cumin oil, oleic acid and Tween 80 on the percutaneous absorption of model lipophilic drug-carvedilol was investigated using excised rat abdominal skin. Transdermal flux, permeability coefficient and enhancement factor were calculated for each penetration enhancer. Black cumin oil (5% v/v) was selected on the basis of its highest enhancement in permeation and was evaluated further for its mode of action using DSC, FTIR and histological studies. The results indicated that the oil shows its action by extraction of lipids from stratum corneum as well as by loosening the hydrogen bonds between ceramides subsequently leading to fluidization of the lipid bilayer.

Protective effects of telmisartan against acute doxorubicin-induced cardiotoxicity in rats.

The therapeutic usefulness of doxorubicin (DXR), an anthracycline antibiotic, is limited by its cardiotoxicity. The present study investigated the effects of telmisartan, an angiotensin II receptor (AT1) antagonist against doxorubicin-induced cardiotoxicity in rats using biochemical and histopathological approaches. Doxorubicin (20 mg/kg) was injected intraperitoneally (ip) as a single dose and telmisartan (10 mg/kg) was administered orally for 7 days. Rats treated with DXR showed cardiotoxicity as evidenced by elevation of serum lactate dehydrogenase (LDH) activity, tissue malondialdehyde (MDA) level, catalase activity and a decrease in the level of glutathione (GSH). Pre- and post-treatment with telmisartan elicited a significant decrease in the activities of LDH and catalase in comparison with DXR-treated group. Furthermore, pretreatment with telmisartan also decreased lipid peroxidation (MDA level) and increased the GSH content in comparison with DXR group. However, the difference in lipid peroxidation and GSH content were not statistically significant in post-treated group. Histopathological studies showed disruption of cardiac tisuues in DXR groups. Pre- and post-treatment with telmisartan reduced the damage of cardiac tissue in rats. These results suggest that telmisartan treatment provides a significant protective effect against acute-doxorubicin induced cardiotoxicity in rats.

A pharmacovigilance study in the department of medicine of a university teaching hospital

The aim of the present study was to monitor adverse drug reactions (ADRs) in the Medicine outpatient department (OPD) of a University Teaching Hospital. Method: A prospective evaluation of the ADRs reported in the Department of Medicine of our University Teaching Hospital over a period of 4-months was conducted. Results: During the study period, a total of 600 patients visited the Medicine OPD and 122 ADRs were reported. Out of 122 reports that were identified, a higher percentage of ADRs in males (52.4%) was observed as compared to females (47.5%). Of the 122 ADRs, 50 were found to be mild (41.0%), 49 moderate (40.2%), and 23 severe (18.2%). A total of 71 (58.0%) ADRs were observed in patients receiving 4 or more medications concurrently. Conversely 46 (37.7%) ADRs were detected in patients using 3 or less medicines. The largest number of reports were associated with antihypertensive therapy (39.3%), followed by antimicrobials (31.1%) and antidiabetics (10.7%). Amongst the organ systems affected, gastrointestinal ADRs constituted a major component (24.7%) followed by skin reactions (22.2%). On causality assessment, nearly 29.5% ADRs were considered as probable, 33.6% possible and 6.6% could not be categorised and were placed under unassessable. Conclusion: The present work is the maiden pharmacovigilance study conducted at our university teaching hospital. The data presented here will be useful in future, long term and more extensive ADR monitoring in the hospital and in promotion of rational prescribing and drug use in the hospital (AU)

El objetivo del presente estudio fue monitorizar las reacciones adversas medicamentosas (RAM) en el departamento de consultas externas (DCE) de un Hospital Universitario. Método: Se realizó una evaluación prospectiva del as RAM comunicada sen el Departamento de Medicinad e nuestro Hospital Universitario durante un periodo de 4 meses. Resultados: Durante el periodo de estudio, 600 pacientes visitaron el DCE y en 122 se comunicaron RAM. De las 122 comunicaciones, se observó un mayor porcentaje de hombres (52,4%) que de mujeres (47,5%). De las 122 RAM, 50 fueron leves (41,0%), 49 moderadas (40,2%) y 23 graves (18,2%). 71 RAM (58,0%) se observaron en pacientes con 4 o más medicamentos simultáneos. Mientras que 46 (37,7%) RAM se observaron en pacientes con 3 o menos medicamentos. El mayor número de comunicaciones estaba asociado a tratamientos antihipertensivos (39,3%), seguidos de antimicrobianos (31,1%) y antidiabeticos (10,7%). Entre los órganos y sistemas afectados, el gastrointestinal constituía el mayor (24,7%) seguido del as reacciones cutáneas (22,2%). Ene n análisis de causalidad, casi el 29,5% de las RAM se consideraron como probables, el 33,6% como posibles y el 6,6% no pudieron clasificarse por ser invalorables. Conclusión: El presente trabajo es el principal estudio de farmacovigilancia realizado en nuestro hospital universitario. Los datos aquí presentados serán útiles para la monitorización futura y más intensa de RAM en el hospital y para promover la prescripción y el uso racionales en el hospital (AU)

A pharmacovigilance study in the department of medicine of a university teaching hospital.

UNLABELLED: The aim of the present study was to monitor adverse drug reactions (ADRs) in the Medicine out patient department (OPD) of a University Teaching Hospital. METHOD: A prospective evaluation of the ADRs reported in the Department of Medicine of our University Teaching Hospital over a period of 4-months was conducted. RESULTS: During the study period, a total of 600 patients visited the Medicine OPD and 122 ADRs were reported. Out of 122 reports that were identified, a higher percentage of ADRs in males (52.4%) was observed as compared to females (47.5%). Of the 122 ADRs, 50 were found to be mild (41.0%), 49 moderate (40.2%), and 23 severe (18.2%). A total of 71 (58.0%) ADRs were observed in patients receiving 4 or more medications concurrently. Conversely 46 (37.7%) ADRs were detected in patients using 3 or less medicines. The largest number of reports were associated with antihypertensive therapy (39.3%), followed by antimicrobials (31.1%) and antidiabetics (10.7%). Amongst the organ systems affected, gastrointestinal ADRs constituted a major component (24.7%) followed by skin reactions (22.2%). On causality assessment, nearly 29.5% ADRs were considered as probable, 33.6% possible and 6.6% could not be categorised and were placed under unassessable. CONCLUSION: The present work is the maiden pharmacovigilance study conducted at our university teaching hospital. The data presented here will be useful in future, long term and more extensive ADR monitoring in the hospital and in promotion of rational prescribing and drug use in the hospital.