Neuropsychological effects among workers exposed to organic solvents / Efectos neuropsicológicos en trabajadores expuestos a disolventes orgánicos

Abstract: Objective: To assess neuropsychological performance among workers at a paint factory in Mexico City. Materials and methods: During 2004 and 2005 we assessed the neuropsychological performance of 208 workers who were exposed to organic solvents at a paint factory, mainly toluene and xylene. We categorized workers into low and high exposure groups using a cumulative index for toluene, based on times spent in different tasks. We evaluated cognitive and motor functions with 13 neuropsychological tests. Results: We found lower attention, longer time to complete the test β=5.5 (R2=12.3%), and a lower score in the motor-cognitive test β=-15.7 (R2=19.5%) in the high exposure group through multiple linear regression model analysis, with adjustment for age and education. Conclusion: Our results are similar to the ones reported in the literature, but the effects are less severe, probably due to lower exposure to organic solvents.

Resumen: Objetivo: Evaluar el desempeño neuropsicológico de los trabajadores de una fábrica de pintura en la Ciudad de México. Material y métodos: Se evaluó el desempeño neuropsicológico de 208 trabajadores expuestos a disolventes orgánicos, principalmente tolueno y xileno, en una fábrica de pintura en la Ciudad de México durante 2004 y 2005. Se categorizaron en grupos de baja y alta exposición con un índice acumulado de tolueno con base en el tiempo empleado por actividad. Se evaluaron funciones motoras y cognitivas con 13 pruebas neuropsicológicas. Resultados: Se registró un tiempo más largo para completar la prueba β=5.5 (R2=12.3%) y una puntuación baja en la prueba motor-cognitiva de β=-15.7 (R2=19.5%) en el grupo de alta exposición en los modelos de regresión lineal múltiple, ajustados por confusores. Conclusión: Los presentes resultados son similares a los reportados en la literatura, aunque los efectos son menos graves, probablemente debido a la baja exposición.

[Effect of kombucha tea on depression and motor activity in mice]

Background: Depression is a threatening disease. Due to adverse effects of chemical antidepressant drugs, researcher's attention has been shifted toward natural drug

Objective: In this work, the antidepressant effect of Kombucha tea [KT] evaluated against reserpine induced depression in mice

Methods: In this experimental study, 42 male mice were randomly divided into 6 groups of 7 mice. Vehicle mice received normal saline [1 mg/kg, i.p.], negative and positive control groups received reserpine [5mg/kg, i.p.] and fluoxetine [20 mg/kg, i.p.] respectively and treatment groups received Kombucha tea at doses of 250, 500, 1000 mg/kg, 18 h after administration of reserpine. Mice were then tested with forced swimming and rotarod tests. At the end of behavioral tests, blood sample were collected and used to assess blood antioxidant capacity

Results: There was significant difference in the duration of immobility time between vehicle and reserpine treated groups [P<0.001]. Administration of Kombucha tea at doses of 250, 500 and 1000 mg/kg into depressed mice significantly reduced the duration of immobility time. KT administration significantly improved blood antioxidant capacity of mice blood

Conclusion: These results provide support for the potential antidepressant effects of Kombucha tea against

Alpha power oscillation in the frontal cortex under Bromazepam and Modafinil effects / Oscilações da potência alfa no córtex frontal sob influência do Bromazepam e Modafinil

ABSTRACTObjective Our aim was to investigate and compare the neuromodulatory effects of bromazepam (6 mg) and modafinil (200 mg) during a sensorimotor task analyzing the changes produced in the absolute alpha power.Method The sample was composed of 15 healthy individuals exposed to three experimental conditions: placebo, modafinil and bromazepam. EEG data were recorded before, during and after the execution of the task. A three-way ANOVA was applied, in order to compare the absolute alpha power among the factors: Group (control, bromazepam and modafinil) Condition (Pre and Post-drug ingestion) and Moment (pre and post-stimulus).Results Interaction was found between the group and condition factors for Fp1, F4 and F3. We observed a main effect of moment and condition for the Fp2, F8 and Fz electrodes.Conclusion We concluded that drugs may interfere in sensorimotor processes, such as in the performance of tasks carried out in an unpredictable scenario.

RESUMOObjetivo Investigar e comparar os efeitos neuromoduladores do bromazepam (6mg) e modafinil (200mg), durante a prática de uma tarefa sensoriomotora, analisando as modificações produzidas na potência absoluta de alfa.Método A amostra foi composta por 15 indivíduos saudáveis, expostos a três condições experimentais: Placebo, modafinil e bromazepam. Dados eletroencefalográficos foram registrados antes, durante e após a execução da tarefa motora. Um ANOVA three-way foi aplicado para comparar a potência absoluta de alfa nos fatores Grupo (controle, bromazepam e modafinil), Condição (Pré e Pós ingestão da droga) e Momento (Pré e Pós estimulo).Resultados Verificou-se interação entre os fatores grupo e condição para os eletrodos Fp1, F4 e F3. Observamos um efeito principal para momento e condição nos eletrodos Fp2, F8 e Fz.Conclusão Concluímos que as drogas, podem interferir em processos sensoriomotores, como no desempenho de tarefas executadas em um cenário imprevisível.

Cleansing the world of the germ of laziness: hygiene, sanitation, and the Javanese population in Suriname / Limpando o mundo do germe da preguiça: higiene, saneamento e população javanesa no Suriname

In 1915 the Rockefeller Foundation took its hookworm eradication campaign to Suriname, but was soon disappointed because of opposition from its main target group: the Javanese. Moreover, authorities and planters objected to the construction of latrines because of the costs and their belief that the Javanese were “unhygienic”. In describing the labor migration from Java to Suriname, I show that this “lack of hygiene” was closely related to the system’s organization. I argue that uncleanliness was the consequence of harmful socio-economic and ecological conditions. Secondly I suggest that even though the Foundation did not manage to cleanse Suriname of hookworm, its educational efforts, its emphasis on prevention, and its training of local health workers probably had more impact than Rockefeller officials thought.

Em 1915, a Fundação Rockefeller levou sua campanha de erradicação da ancilostomíase ao Suriname, logo sofrendo a oposição de seu principal alvo, os javaneses. Autoridades e proprietários rurais também reagiram à instalação de latrinas devido aos custos implicados e à crença de que os javaneses eram “anti-higiênicos”. Ao descrever a migração de trabalhadores de Java para o Suriname, mostro que a “falta de higiene” ligava-se à organização do sistema. Argumento que a sujeira era consequência de condições ecológicas e socioeconômicas danosas. Sugiro ainda que, embora a Fundação não tenha livrado o Suriname da anciolostomíase, seus esforços educacionais, sua ênfase na prevenção e o treinamento de profissionais de saúde locais tiveram maior impacto do que o imaginado pelos funcionários da agência norte-americana.

Central nervous system stimulant actions of Alpinia galanga (L.) rhizome: A preliminary study.

Methanolic and ethyl acetate extract of A. galanga showed significant central nervous system (CNS) stimulant activity in mice using actophotometer and rotarod test. CNS stimulation at a dose of 500 mg/kg was comparable with standard drugs caffeine and amphetamine derivative modalart. The extracts did not shown any depressant effect in forced swim or tail suspension tests. It can be concluded that A. galanga rhizome may have stimulant activity in mice and the active constituents responsible for this effect is present both in crude methanolic extract as well as in ethyl acetate fraction of methanolic extract of this plant species.

The influence of estazolam on human neurobehavioral function / 法医学杂志

OBJECTIVE@#To study the relation between human blood estazolam concentration and neurobehavioral function.@*METHODS@#The neurobehavioral ability of 10 volunteers were measured with computer-administered neurobehavioral evaluation system-chinese3 (NES-C3) and SMART EquiTest system.@*RESULTS@#The neurobehavioral ability and balance function declined 1 h later after dosing estazolam. The neurobehavioral ability index and balance function declined to the lowest level 3 h later after dosing estazolam. The neurobehavioral ability recovered partly 6 h later after dosing estazolam, and neurobehavioral ability recovered completely 10 h later.@*CONCLUSION@#Driving ability was impaired when estazolam concentration in blood is 20 ng/mL, and the neurobehavioral ability declined when estazolam concentration is 40 ng/mL in blood. The influence to human in absorption process is greater than the metabolic process with the same estazolam concentration.

Effects of a cognitive modulator in the theta and alpha asymmetry during a typewriting task: a sensorimotor integration perspective / Efeitos de um modulador cognitivo na assimetria de teta e alfa durante uma tarefa de datilografia: uma perspectiva da integração sensório-motora

This study aimed to elucidate cortical mechanisms and to identify the areas where occur such mechanisms due to interaction between bromazepam and motor learning. The sample was composed of 45 healthy subjects randomly distributed in 3 groups: placebo (n=15), bromazepam 3 mg (n=15) or bromazepam 6 mg (n=15). To perform the experimental task, subjects sat comfortably at a distance of approximately 20 cm from the typewriter. The typewriter keyboard was covered with a wooden box to avoid visual information about the hands' position. The typewriting task was performed concomitantly with EEG recording. ANOVA two-way results indicated a decreased asymmetry in sensorimotor areas in the experimental groups. Our interpretation is that moderate doses of bromazepam may improve performance on tasks with predictable elements to promote stability of psychomotor functions, but may also impair performance on tasks executed in unpredictable environments.

O objetivo do estudo foi elucidar mecanismos corticais e identificar as áreas onde estas ocorrem tais mecanismos devido à interação entre bromazepam e aprendizagem motora. A amostra compreendeu 45 sujeitos hígidos distribuídos randomicamente em 3 grupos: placebo (n=15), bromazepam 3 mg (n=15) ou bromazepam 6 mg (n=15). Para a realização da tarefa experimental, sujeitos sentaram-se confortavelmente a uma distância de aproximadamente 20 cm da máquina de escrever. O teclado da máquina foi coberto com uma caixa de madeira para evitar informações visuais sobre a posição das mãos. O registro do EEGq ocorreu simultaneamente à tarefa de datilografia. Os resultados da ANOVA two-way indicaram menor assimetria em áreas sensório-motoras nos grupos experimentais. Nossa interpretação é que doses moderadas de bromazepam podem melhorar o desempenho em tarefas previsíveis por promover estabilidade das funções psicomotoras, mas pode prejudicar o desempenho em tarefas realizadas em ambientes imprevisíveis.

Comparative effects of conventional B-blockers and nebivolol on psychomotor performances in healthy volunteers: a preliminary report.

The present study was under taken to assess the comparative effects of nebivolol with propranolol and atenolol on psychomotor performances. Thirty healthy volunteers were randomized into three groups with n=10 in each group. Each subject received single dose of one of the three medications (nebivolol 5 mg, atenolol 50 mg and propranolol 40 mg) in morning (9:00 AM). Just before administering the drug, the pre-drug scores were taken, followed by post drug score obtained for consecutive six hours. Psychomotor assessment was carried out by three tests Simple Reaction Timer (SRT), Critical Flicker Fusion Frequent Threshold (CFFT) and Digit Cancellation Test (DCT). The results of present study indicate that single doses of atenolol and propranolol produced significant impairment of psychomotor performance. Nebivolol also impaired psychomotor performance tests in the similar fashion to atenolol and propranolol. Hence, the findings of the present study correlate with the lipophilic nature of the nebivolol.

Physical growth and psychomotor development of infants exposed to antiepileptic drugs in utero.

OBJECTIVE: To evaluates the physical growth and psychomotor development of infants born to women with epilepsy on regular Anti Epileptic Drugs (AEDs). SETTING: Govt. Stanley Medical College and Hospital, Tertiary care referral centre, Chennai. DESIGN: Open prospective cohort study with a control group. MATERIALS AND METHODS: Consecutive women with epilepsy who were on regular anticonvulsants were followed up from their first trimester. Their babies were examined at birth and anthropometric measurements including anterior fontanelle size were noted. They were followed up till one year and periodically evaluated at 1st, 6th and 12th month of age. Development testing using Griffith scale was done at 2nd, 6th and 12th month. An equal number of control babies were also studied using the same scale for one year at the specified intervals. The results in both the groups were compared. RESULTS: 30 babies were enrolled in the case and control group. The AEDs received by the mothers with epilepsy were Phenytoin, Carbamazepine, and Sodium valproate. At birth and 1st month the weight, head circumference and length of case and control babies were equal. At 6th and 12th month reduction in the above 3 parameters were noted in the case babies ( P < 0.01). Area of anterior fontanelle (AF) was larger in the study group particularly in those exposed to phenytoin in utero (P < 0.001). In the case babies reduction in the sitting, prone and erect progression of the locomotor scores was observed at 2nd month (P < 0.001). Prone progression alone improved by 12th month and other two remained less than the control (P < 0.001). No difference was observed in reaching behaviour and personal/social scores in both groups. Infants exposed to Phenytoin monotherapy had a negative impact on sitting progression. CONCLUSION: Among infants exposed to AEDs in utero physical growth was equal to that of control at birth but reduced at 6th and 12th month probably due to extraneous factors. The Locomotor scores showed reduction in all areas in 2nd, 6th and 12th month except prone progression which alone improved by 12th month. Phenytoin exposure in utero resulted in large AF and it had a negative impact on sitting progression in comparison with Carbamazepine and Sodium valproate.

Supplementation of fish-oil and soy-oil during pregnancy and psychomotor development of infants.

Supplementation of docosahexaenoic acid (DHA) in infancy improves neuro-developmental outcomes, but there is limited information about the impact of supplementing pregnant mothers with DHA on the development of their infants. In a follow-up of a randomized, double-blind controlled trial with 400 pregnant mothers, the effects of supplementation of fish-oil or soy-oil (4 g/day) during the last trimester of pregnancy on psychomotor development and behaviour of infants at 10 months of age (n=249) were assessed. The quality of psychosocial stimulation at home (HOME) and nutritional status of the subjects were also measured. There were no significant differences in the fish-oil group and soy-oil group in any of the developmental (mean +/-SD mental development index: 102.5 +/- 8.0 vs. 101.5 +/- 7.8, psychomotor development index: 101.7 +/- 10.0 vs. 100.5 +/- 10.1) or behavioural outcomes. It may, therefore, be concluded that supplementation of fish-oil during the last trimester of pregnancy does not have any added benefit over supplementation of soy-oil on the development or behaviour of infants in this population.

Efeitos neuromoduladores do bromazepam quando indivíduos são expostos a uma tarefa de aprendizagem motora: eletrencefalografia quantitativa (EEGq) / Neuromodulatory effects of bromazepam when individuals were exposed to a motor learning task: quantitative electroencephalography (qEEG)

Os efeitos sedativos do bromazepam no desempenho cognitivo têm sido amplamente investigados. Várias abordagens têm sido implementadas no intuito de avaliar a influência do bromazepam em sujeitos submetidos à tarefa motora. Neste contexto, o presente estudo objetiva avaliar as alterações eletrofisiológicas em sujeitos expostos à tarefa de datilografia e tratados com bromazepam (6 mg). Os dados do EEGq foram gravados simultaneamente à tarefa. Em particular, a potência relativa na banda delta (0,5-3,5 Hz) foi analizada. O tempo de execução e erros durante a tarefa foram considerados variáveis comportamentais. O grupo experimental (bromazepam 6 mg) demonstrou melhor desempenho e valores de potência relativa mais elevados que o grupo controle (placebo). Estes resultados sugerem que menor nível de ansiedade favorece o desempenho motor.

Disminución de ácido fólico y alteraciones cognitivas en pacientes con epilepsia tratados con fenitoína o carbamazepina, estudio piloto / Decrease of folic acid and cognitive alterations in patients with epilepsy treated with phenytoin or cartnabazepine, pilot study

Introduction. Phenytoin and carbamazepine were the antiepileptic drugs most frequently used in Mexico and throughout the world. Epileptic patients who take these drugs have a variety of collateral effects including the decrease of Mates plas-matic level. Low serie folie acid concentration has been associated with a decline in cognitive functions. The administration of a combined treatment with folie acid could ameliorate these difficulties. Objective.To describe the effect of the folie acid in the cognitive function in epileptic patients who take phenytoin and carbamazepine. Methods. We chose patient who have epilepsy and that are being treated with phenytoin, carbamazepine or both and formed two groups. The study group was treated with a daily dose of 5 mg of folie acid and the control group was administered placebo for a period of six months, with nine patients in each group of same age, sex, education level, epilepsy's evolution, frequency of seizures, EEG abnormalities and antiepileptic drugs plasma levels. We registered data at the beginning (basal) and at the end of the study. Results.Measurements of basal folie acid plasma levels in both groups were under the referential value. The neuropsychological assessment at the beginning (Mini-Barcelona test) showed a deficit in the verbal memory skills in both groups. After six months of treatment with folie acid (study group), the folie acid plasma level was 12.2 mg/mL (p < 0.01) higher than the basal value. Verbal memory test has improved with respect to the basal value (p < 0.05). The numbers of seizures and the plasma levels of the antiepileptic drugs remained unchanged. On the other hand, the group treated with placebo did not improve. Conclusion.Treatment with folie acid is safe and without side effects, it improved the cognitive function in patients with epilepsy treated with phenytoin and carbamazepine.

Introducción. La difenilhidantoína (DFH) y la carbamazepina (CBZ) son los antiepilépticos más empleados en México y en el mundo, los pacientes con epilepsia que emplean estos fármacos presentan una disminución en las concentraciones séricas de ácido fólico, una de las causas que pueden contribuir a un deterioro cognitivo, por lo que la terapia sustitutiva con ácido fólico pudiera mejorar estas alteraciones. Objetivo. Describir el efecto de la disminución del ácido fólico en la cognición de pacientes con epilepsia tratados con difenilhidantoína y carbamazepina. Material y métodos. Incluimos pacientes tratados con carbamazepina, fenitoína o ambos, con epilepsia. Formamos dos grupos: Un grupo experimental recibió ácido fólico 5 mg/día y otro grupo control recibió placebo durante seis meses, nueve pacientes en cada grupo; pareados en la edad, sexo, escolaridad, tiempo de evolución, námero de crisis, alteraciones EEG, niveles séricos de anticonvulsivos, realizamos estudios neuropsicológicos al inicio (básales) y al final del estudio a ambos grupos. Resultados. Las básales del ácido fólico en ambos grupos estuvieron por debajo del valor de referencias. En las pruebas neuropsicológicas (básales) (prueba de Mini-Barcelona) se halló un déficit en el área de la memoria verbal en ambos grupos. Después de seis meses de tratamiento con ácido fólico (grupo experimental) los niveles de ácido fólico alcanzaron 12.2 ng/mL (p < 0.01) con respecto a su basal; las pruebas de memoria verbal mejoraron con respecto a su basal (p < 0.05); el námero de crisis y los niveles séricos de los anticonvulsivos no se modificaron. El grupo con placebo no presentó ninguna mejoría. Conclusiones. El tratamiento coadyuvante con ácido fólico es seguro, libre de efectos adversos y mejoró las alteraciones cognitivas (memoria verbal) de estos pacientes.

Effects of caffeine on the electrophysiological, cognitive and motor responses of the central nervous system

Caffeine is the most consumed psychoactive substance in the world. The effects of caffeine have been studied using cognitive and motor measures, quantitative electroencephalography (qEEG) and event-related potentials. However, these methods are not usually employed in combination, a fact that impairs the interpretation of the results. The objective of the present study was to analyze changes in electrophysiological, cognitive and motor variables with the ingestion of caffeine, and to relate central to peripheral responses. For this purpose we recorded event-related potentials and eyes-closed, resting EEG, applied the Stroop test, and measured reaction time. Fifteen volunteers took caffeine (400 mg) or placebo in a randomized, crossover, double-blind design. A significant reduction of alpha absolute power over the entire scalp and of P300 latency at the Fz electrode were observed after caffeine ingestion. These results are consistent with a stimulatory effect of caffeine, although there was no change in the attention (Stroop) test or in reaction time. The qEEG seems to be the most sensitive index of the changes produced by caffeine in the central nervous system since it proved to be capable of detecting changes that were not evident in the tests of cognitive or motor performance.

Analysis of the influence of bromazepam on cognitive performance through the visual evoked potential (P300)

Benzodiazepínicos têm sido utilizados no tratamento farmacológico da ansiedade há mais de quatro décadas. No entanto, poucos estudos têm combinado bromazepam e potencial evocado relacionado a evento (PRE). O presente estudo teve por objetivo investigar os efeitos modulatórios desta droga na dinâmica cerebral. Especificamente, os efeitos de 3mg de bromazepam no componente P300 do PRE foram analisados em um experimento duplo-cego. A amostra consistiu de 15 sujeitos sadios (7 homens e 8 mulheres), submetidos a uma tarefa de discriminação visual utilizando o paradigma "oddball". Medidas eletrofisiológicas (P300) e comportamentais (stroop, digit span, e tempo de reação) foram analisadas em três condições experimentais: placebo 1, placebo 2 e bromazepam. Os resultados sugerem que os efeitos de 3mg de bromazepam em processos cognitivos não são aparentes. Apesar do que parece irrefutável na literatura, o bromazepam não produziu efeitos evidentes nas variáveis comportamentais e eletrofisiológicas analisadas.

Avaliação de riscos ao desenvolvimento neuropsicomotor em crianças: triagem utilizando-se o Teste de Denver II e identificação de fatores maternos de risco / Assessment of risk to neuro-psychomotor development: screening using the Test Denver II and identification of maternal risks

PURPOSE: To identify a positive screening test for developmental delay in children by the Denver Test II and their risk factors. METHODS: A sample of 398 children was studied at 0 the 12 months of age regarding their neurodevelopment. The Denver II Test was used. The children who failed in two or more items of the test were suspected of having neurodevelopment delay. A set of independent variables was: socioeconomic, reproductive and environmental, birth conditions children's care. Analyses were performed using chi-square test and multivariate techinique logistic regression. RESULTS: At of 0 - 12 months of age, 45,73% (182) of the total of 398 children failed in the screening test. After adjusting for possible confounding variables, failure was associated with family lower income children, gestacional age less than 38 weeks, socioeconomic status family, schooling of the mother, mother's age, use of drug. CONCLUSIONS: This study demonstrates: 1--The Denver Test permited screening the delays development; 2--Maternal risk factors may interfere in the child's neurodevelopmental.

Effects of caffeine on visual evoked potencial (P300) and neuromotor performance

Os efeitos estimulantes da cafeína no desempenho cognitivo vêm sendo amplamente investigados. O potencial evocado visual (P300) tem sido empregado em estudos recentes que buscam elucidar os mecanismos excitatórios da cafeína através de métodos neurofisiológicos. Neste contexto, o presente estudo objetivou examinar as variações geradas pela cafeína em respostas eletrofisiológicas (latência do P300) e determinar modificações no desempenho cognitivo e motor. Para tanto, 15 indivíduos hígidos, sendo 9 mulheres e 6 homens (26 ± 5 anos, 67 ± 12,5 kg) foram submetidos por três vezes à seguinte rotina: aquisição de sinais eletroencefalográficos, Word Color Stroop Test e tarefa de discriminação visual. Foi administrada uma cápsula gelatinosa de 400 mg de cafeína ou de placebo (P1 e P2) em um desenho randomizado duplo-cego cruzado. Foi empregada a ANOVA com um fator e post hoc de Tukey - HSD para a comparação das variáveis nos momentos C, P1 e P2. O momento cafeína apresentou redução não significativa no tempo de reação, no tempo de execução do Stroop e na latência em Cz. Observou-se também aumento não significativo no escore bruto do Stroop e na latência em Pz. O único resultado significativo encontrado foi na latência em Fz. Assim, pode-se concluir que a tendência favorável à ingestão de cafeína na melhora das respostas cognitivas pode estar relacionada a mudanças em regiões específicas do cérebro, como o córtex frontal, área amplamente relacionada com os processos de atenção.

Antiepileptic activity of Panax ginseng against pentylenetetrazole induced kindling in rats.

In the present study, Panax ginseng was evaluated for its antiepileptic activity against pentylenetetrazole (PTZ) induced chemical kindling in rats. PTZ was injected at the dose of 30 mg/kg, i.p. on alternate days and the occurrence of generalized tonic clonic convulsions were considered as the end point. One group received Panax ginseng every day, at a dose of 100 mg/kg, 30 min prior to PTZ injection whereas the other group received an equal volume of distilled water to serve as control. In a separate group the rats were evaluated for motor performance tests after Panax ginseng. The rats treated with Panax ginseng showed significant protection as compared to vehicle treated PTZ injected rats. The study suggests to potential of Panax ginseng against seizures.

Studies on psychomotor performance in healthy volunteers after diazepam, propranolol and alcohol given alone or in combination.

The effects of diazepam, propranolol or alcohol alone or in combination with each other were examined in ten normal healthy volunteers on tests of psychomotor function. Results showed impaired psychomotor performance persisting upto 4-5 h when the aforementioned agents given singly were tested on simple reaction time (SRT), multiple choice reaction time (MCRT) and critical flicker fusion frequency (CFFF) tasks. Digit cancellation task (DCT) was similarly affected by diazepam and alcohol only. No summation of adverse effects on psychomotor performance was noted when a combination of diazepam and alcohol, diazepam-propranol or alcohol plus propranolol were tested on SRT and MCRT. An additive impairment of CFFF was observed with alcohol - propranolol combination only. No summation of pharmacodynamic effects on DCT were noted when different combinations were used.

Effects of ranitidine alone and in combination with chlorpheniramine on histamine-induced wheal and flare and psychomotor performance.

Some reports suggest that addition of an H2 antagonist increases the efficacy of H1 antagonist but the influence on the side effect profile of antihistamines are largely unknown. The effects of ranitidine, chlorpheniramine, their combination and placebo on histamine induced wheal and flare, psychomotor performance and subjective symptoms were studied in 6 healthy male volunteers in a double blind randomized and cross-over (Latin square) study. Ranitidine significantly reduced the histamine induced wheal at 4 hrs (P < 0.05). Chlorpheniramine and the combination significantly reduced both histamine induced wheal and flare at 2 hrs and at 4 hrs (P < 0.05). Addition of ranitidine reduced the feeling of sleepiness produced by chlorpheniramine, though other subjective symptoms were not affected. None of the treatment schedules produced any consistent change in the psychomotor performance of the volunteers.

Effect of fatty diet on pharmacokinetics and pharmacodynamics of a liquid theophylline preparation in volunteers.

The effect of a standard breakfast and a fatty breakfast on the pharmacokinetics and pharmacodynamics of a theophylline liquid preparation (160 mg-single dose) was examined in 6 healthy, non-smoking male volunteers. The plasma theophylline concentrations after both standard and fatty diet were found to be comparable at each point of time and pharmacokinetic parameters like Cmax, Tmax, T1/2a, T1/2 beta and AUC0-alpha, were also comparable. However, the time taken to attain the therapeutic plasma concentration was earlier and sustained along with the standard breakfast in comparison to that with fatty breakfast. Peak change in PEFR and pulse rate was also observed earlier with the standard diet than with fatty diet. The plasma theophylline concentrations produced after both diets were insufficient to produce any detectable change in subjective symptoms like tremor palpitation, heart burn, nausea, restlessness and tenseness. However, theophylline after fatty breakfast was better tolerated than that after a standard breakfast.