Class of 2005 Abstract / Objectives: To determine whether the quantity of active ingredient and content uniformity of atenolol and captopril manufactured in Mexico are comparable with those manufactured in the United States. Methods: An adapted United States Pharmacopoeia-National Formulary (USP-NF) guideline was utilized for a high-performance liquid chromatography (HPLC) assay to quantify the active ingredient of each medication. The US products were considered to contain 100% of the active ingredient, with acceptable variance range of 90-110%. Atenolol 50 milligrams (mg) and captopril 50 mg tablets, manufactured from either Mexico or US, were tested in this comparative study. Results: Quantification of active ingredient in Mexican captopril 50 mg tablets were within the acceptable range of the USP-NF guidelines at 94.2%. The content uniformity was also within the acceptable range of the USP-NF guidelines at 99.0%. The quantity of active ingredient in the Mexican atenolol 50 mg tablets, as well as content uniformity, was also within the acceptable range of the USP-NF guidelines at 110.0% and 95.0%, respectively. Implications: The results of this study showed that captopril and atenolol manufactured in Mexico were comparable to those manufactured in the US with no significant differences regarding amount of active ingredient and content uniformity.

Orientador: Gilberto de Nucci / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-11T00:01:00Z (GMT). No. of bitstreams: 1 Gil_AnaCeciliaMontes_D.pdf: 1050627 bytes, checksum: 72f41a4bdcddba6633b8b082cc0ee0a0 (MD5) Previous issue date: 2007 / Resumo: No presente trabalho, foram avaliados os efeitos farmacológicos do Aspirinato de atenolol (AA T) uma potencial pró-droga mútua resultado da combinação química entre ácido acetilsalicílico (AAS) e atenolo!. As propriedades do AA T como droga antitrombótica foram avaliadas na inibição da agregação plaquetária estimulada in vitro e na inibição da produção de tromboxano estimulada ex-vivo em sangue de animais tratados. Por outro lado, o AA T foi avaliado como droga anti-hipertensiva no modelo de hipertensão induzida pela inibição crônica da síntese de NO em ratos, e seus efeitos como antagonista dos adrenoceptores 13 foram avaliados na resposta cronotrópica ao isoproterenol em átrios isolados. Foi determinada a estabilidade metabólica em diferentes frações subcelulares hepáticas, plasma e soluções tampão de diferente pH, assim como seu perfil farmacocinético após administração endovenosa. Também foram avaliadas as propriedades ulcerogênicas gástricas e o potencial mutag'ênico através do Teste de Ames. Os resultados mostraram na avaliação do efeito antiplaquetário, que o AA T não inibiu a agregação plaquetária induzida pelo ácido araquidônico em nenhuma das concentrações testadas e apesar d~ ini~ir significativamente a produção de tromboxano estimulada ex-vivo em rat6s e na maior dose testada em camundongos, este efeito inibitório foi menor quando comparado com o AAS. O acoplamento com AAS, na molécula de AAT, suprimiu os efeitos do atenolol como antagonista dos adrenoceptores 13. Igualmente, o AA T não reduziu a freqüência cardíaca e pressão arterial após tratamento oral crônico de ratos hipertensos, estes resultados indicaram que não houve liberação de atenolol desde a molécula de AA T. Na avaliação da estabilidade metabólica e farmacocinética, observamos que o AA T seguiu uma rápida e completa hidrólise no grupo orto-acetila, gerando salicilato de atenolol (SA T), este produto foi formado quando o AA T foi submetido à hidrólise plasmática (T% 7,6 min) e aquosa (T% 56,5; 24,9 e 6,4 nos pH 2,5; 7,4 e 9.4 respectivamente) metabolização hepática e também após administração endovenosa em cães. o salicilato de atenolol formado a partir do AA T nas frações subcelulares hepáticas foi metabolizado apenas na fração microssomal gerando dois metabólitos hidroxilados em posições diferentes na molécula, a formação destes metabólitos foi dependente do tempo e paralela à cinética de desaparecimento do SAT. Após administração endovenosa, concentrações de AA T não foram detectadas em plasma. Atenolol e ácido salicílico (AS), foram liberados a partir da molécula de SAT (após clivagem da ligação éster benzoato) em concentrações significativamente menores às concentrações obtidas nos grupos tratados com AAS ou atenoloL A ASC0-24h calculada para o AS no grupo tratado com AA T correspondeu ao 0,71% da área calculada para o grupo que recebeu AAS. Similarmente, a ASC0-24h do atenolol no grupo tratado com AA T correspondeu a 1,44% da área calculada para ~ grupo tratado com atenolol. O AA T e seu principal metabólito SA T, não apresentaram propriedades mutagênicas, obtendo-se resultados negativos no Teste de Ames. O AA T produziu lesões na mucosa gástrica significativamente menores às observadas com o AAS após administração oral aguda e crônica durante 4 semanas. Devido às relevantes diferenças obtidas entre o AA T, AAS ou atenolol na caracterização farmacológica e farmacocinética, concluímos que o AA T não atua como pró-droga mútua de AAS e atenolol, e modificações futuras na molécula devem ser consideradas com a finalidade de desenvolver aspirinatos cardioativos com potencial efeito farmacológico / : In this study, we evaluated the pharmacologica/ effects of Atenolol Aspirinate (A TA) a potential mutual prodrug that resulted of the chemical combination between Acetyl Salicylic Acid (ASA) and atenolo!. The properties of ATA as anthithrombotic drug were evaluated on the inhibition of in vitro stimulated platelet aggregation and on the inhibiton of ex-vivo stimulated thromboxane production in blood from treated animais. Additionally, A TA was evaluated as an antihypertensive drug on the hypertension induced by chronic inhibition of NO in rats, its effects as antagonist of f3 adrenoceptors were evaluated in the chronotropic response to isoproterenol in isolated atria. The metabolic stability was determined in different hepatic subcellular fractions, plasma and buffer solutions as well as its pharmacokinetic profile after intravenous administration. The gastric ulcerogenic properties and mutagenic potencial, using the Ames test, were toa evaluated. In the evaluation of the antiplatelet effect, our results showed that ATA had no effect on arachidonic acid induced platelet aggregation. Although it inhibited significantly the ex-vivo stimulated thromboxane production in rats and in the highest tested dose in mice, ATA showed lower inhibitory effect than ASA. The coupling with ASA, in the ATA mOlecule, abolished the atenolol effects as antagonist of f3 adrenoceptors. In the sa~e"way, ATA had no effect reducing the heart rate and blood pressure after chropic oral treatment of hypertensive rats, these results showed that atenolol was not liberated from ATA molecule. In the evaluation of the metabolic stability and pharmacokinetics, we observed that ATA followed a rapid and complete hydrolysis at the o-acetyl group, generating atenolol salicylate (A T8), this product was formed when ATA was submitted to plasma hydro/ysis (T% 7;6 min) and aqueous hydrolysis (T% 56,5; 24,9 and 6,4 at pH 2,5; 7,4 and 9.4 respectively), hepatic metabolization and after intravenous administration to dogs. ATA was biotransformed to A TS in ali hepatic subcellular fractions, then A TS was metabolized only in the microsomal fraction generating two hydroxylated metabolites, whose formation was time dependent and parallel to the kinetics of A TS consumption. After intravenous administration, concentrations of A TS instead ATA were found in plasma dog samples, SA and atenolol were originated from cleavage of A TS molecule at the benzoate ester linkage, generating concentration levels to a lesser extent than levels found after treatment with an equimolar dose of the drugs ',nóiviõua / Doutorado / Doutor em Farmacologia

Objective: Dosing intervals of 12 and 24 hours for atenolol have been recommended, but an evidentiary basis is lacking. To test the hypothesis that repeated, once-daily oral administration of atenolol attenuates the heart rate response to isoproterenol for 24 hours, we performed a double-blind, randomized, placebo-controlled cross-over experiment. Animals: Twenty healthy dogs Procedures: Dogs were randomly assigned to receive either placebo (P) and then atenolol (A), [1 mg/kg PO q24h] or vice versa. Treatment periods were 5-7 days; time between periods was 7 days. Heart rates (bpm) at rest (HRr) and during constant rate [0.2 μg/kg/min] infusion of isoproterenol (HRi) were electrocardiographically obtained 0, 0.25, 3, 6, 12, 18, and 24 hours after final administration of drug or placebo. A mixed model ANOVA was used to evaluate the effects of treatment (Tr), time after drug or placebo administration (t), interaction of treatment and time (Tr*t) as well as period and sequence on HRr and HRi. Results: Sequence or period effects were not detected. There was a significant effect of Tr (p <0.0001) and Tr*t (p <0.0001) on HRi. Atenolol significantly attenuated HRi for 24 hours but did so maximally at 3 hours (least squares means ± SE, A: 146±5 bpm, P: 208±5 bpm); the effect at 24 hours was small (A: 193±5, P: 206±5). Atenolol had a small but significant effect (p <0.0001) on HRr. Conclusions and Clinical Relevance: The results of this study support a dosing interval that is less than 24 hours. / MS / This thesis was designed to test the effects of the drug atenolol on heart rate in dogs. Atenolol is used to reduce the heart rate of dogs with cardiovascular disease. The study used 20 dogs that were given oral capsules in both a placebo (no drug) and atenolol phase of the experiment. The study was designed to control for other causes of slower heart rate and make sure that the investigator did not know which treatment was given to a dog. Placebo dogs had a high heart rate response to the drug isoproterenol whereas atenolol treated dogs had a statistically significant lower heart rate response compared to placebo over a 24 hours period of time. The difference between treatments was small after 24 hours and further work is needed to determine the best time interval between doses of medication.

Made available in DSpace on 2014-06-11T19:33:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-15Bitstream added on 2014-06-13T19:03:54Z : No. of bitstreams: 1 elias_gp_dr_araca.pdf: 1560641 bytes, checksum: 3dad8c2298005cfeb8d0a078880f5e66 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho foi avaliar a atividade das glândulas salivares, a mineralização dental e a participação da metaloproteinase de matriz (MMP-9) nesta mineralização em filhotes de ratas espontaneamente hipertensas (SHR) tratadas ou não com atenolol. Ratas SHR e normotensas Wistar foram tratadas com atenolol (100mg/Kg/dia, via oral) durante os períodos de prenhez e lactação. Os grupos controle receberam o mesmo volume de água sem atenolol. O fluxo salivar, induzido por nitrato de pilocarpina, a concentração de proteínas (método de Lowry), a atividade da amilase (método cinético a 405 nm), o peso das glândulas salivares (parótidas, submandibulares e sublinguais), a microdureza do esmalte e da dentina de incisivos e molares e a expressão da MMP-9 (imonuperoxidase) no tecido dental foram comparados entre filhotes de ratas SHR e Wistar tratadas ou não com atenolol. Os resultados obtidos foram submetidos ao teste estatístico mais adequado, paramétrico (ANOVA ou test t de Student’s) ou não paramétrico (Kruskal-Wallis), sendo consideradas significativas as diferenças quando p<0,05. Filhotes SHR apresentaram menor fluxo salivar e concentração de proteínas do que filhotes Wistar, mas a atividade da amilase não foi diferente entre os grupos. O peso das glândulas salivares foi semelhante entre filhotes SHR e Wistar... / The objective of the present study was analyzed the salivary activity, the dental mineralization and the role of matrix metalloproteinase-9 (MMP-9) on this mineralization, in pups (30 days) of spontaneously hypertensive rats (SHR) treated, or not treated, with atenolol. Female SHR and normotensive Wistar rats were treated during pregnancy and lactation periods with Atenolol 100mg/Kg/day by oral administration. For the control group, the animals received the same water volume without the drug. The salivary flow rate (stimulated by pilocarpine injection), the protein concentration (Lowry method), salivary amylase activity (kinetic method at 405 nm), the weight of salivary glands (parotid, submandibular and sublingual), the enamel and dentin microhardness of incisors and molars teeth and the matrix metalloproteinase-9 (MMP-9, gelatinase B) localization (imunoperoxidase) in dental tissue were compared between SHR and Wistar pups of female rats treated or not with atenolol. The results were analyzed by parametric (ANOVA or Student s tests) or non-parametric (Kruskal-Wallis) tests (p<0,05). The salivary flow rate and salivary protein concentration were reduced in SHR pups. There was no alteration in amylase activity between groups. The salivary glands weight was not different between SHR and Wistar pups either. Decreased enamel and dentin microhardness were observed in incisors and molar teeth of SHR pups. No alterations in MMP-9 positive staining were observed in predentin and odontoblasts of both groups, however the density of stained ameloblasts cells and external enamel surface were higher in incisors teeth of SHR pups. Atenolol-treated SHR and Wistar rats pups showed decrease in submandibular gland weight, in saliva s flow rate and protein concentration, but no alteration in amylase activity. Atenolol increased enamel and dentin microhardness of incisors teeth of SHR and...(Complete abstract, click electronic address below)

The atenolol is a selective β-blocker that acts specially on β-one adrenergic receptors of the heart, used in the control of high blood pressure, pectoris angine, cardiac arrhythmias and the treatment of miocardic stroke. This paper aimed to optimize the described methodologies for drugs and tablets of atenolol. It proposes to develop and validate simple and more accessible tests to evaluate atenolol tablets and raw material. It also emphasizes the ideal characteristics for drugs in the pre-formulation and development of the pharmaceutical form. Methodologies were developed and validated by HPLC and UV spectrophotometric for the quantification of atenolol in tablets. Raw material characterization techniques were also applied for the classification of atenolol in the pre-formulation. A pharmaceutical equivalence test was performed and compared to the national market reference drug. The HPLC developed method presents advantages over the official methodology to establish an analysis without the use of ionic pareator heptane sulphonate, for being faster and more simple. Both quantitative development methods were linear, specific exact, precise, robust and equivalent between themselves. For the dissolution performed with atenolol pharmaceutical form, after the dissolution efficiency analysis no meaningful difference were observed between the obtained dissolution curves through developed methods and the pharmacopeial methodology. The atenolol raw material analysis permitted its characterization, assuring an adequate use in the pharmaceutical form manufacturing. The comparative analysis between the test drug and reference drug allowed to claim that the two formulations are similar and with the some in vitro performance, i.c., they are pharmaceutical equivalent. The described methods are useful in routine quality analysis control of atenolol. The comparative analysis between the proposed methods and official methodology demonstrated that there is no statistical meaningful differences characterizing their equivalence. / O atenolol é um betabloqueador seletivo que age preferencialmente sobre os receptores adrenérgicos beta-1 do coração, utilizado no controle da hipertensão arterial, angina pectoris, arritmias cardíacas e no tratamento do infarto do miocárdio. Este trabalho tem o objetivo de otimizar as metodologias descritas para a avaliação do fármaco e comprimidos de atenolol, através do desenvolvimento e validação de métodos simples e mais acessíveis para avaliação de comprimidos e matéria prima de atenolol. Procura, também, destacar as características ideais para o fármaco na fase de pré-formulação e desenvolvimento da forma farmacêutica. Neste contexto, foram desenvolvidas e validadas metodologias por cromatografia líquida de alta eficiência (CLAE) e espectrofotometria no ultravioleta para quantificação de atenolol em comprimidos. Foram também aplicadas técnicas de caracterização da matéria prima para classificação da mesma na fase de pré-formulação. O método desenvolvido por cromatografia líquida de alta eficiência apresenta vantagens sobre o método farmacopeico por estabelecer uma análise sem utilização de reagente de pareamento iônico, heptanossulfonato, por ser mais rápido e simples. Ambos os métodos quantitativos desenvolvidos apresentaram-se lineares, específicos, exatos, precisos, robustos, e equivalentes entre si. Para o estudo de dissolução realizado com as formulações farmacêuticas de atenolol, após a análise de eficiência de dissolução, não se observou variação significativa entre as curvas de dissolução obtidas através dos métodos desenvolvidos e da metodologia farmacopeica. A análise da matériaprima de atenolol permitiu sua caracterização, garantindo um emprego adequado na fabricação da forma farmacêutica. As análises comparativas entre o medicamento teste e o medicamento referência permitem afirmar que as duas formulações são semelhantes e com mesmo desempenho in vitro, isto é, são equivalentes farmacêuticos. Os métodos descritos são úteis em análise de controle de qualidade rotineira de formulações farmacêuticas de atenolol e a análise comparativa entre os métodos propostos e a metodologia oficial, demonstrou não haver diferença estatisticamente significativa, caracterizando a equivalência dos mesmos.

Chicken embryos were chronically exposed to the ?1- blocker atenolol during one of three stages: mesonephros (E7-E9), mesonephros-metanephros (E11-E13), or metanephros (E15-E17). Mesonephros group hearts were larger than all other groups (P < 0.01). Mesonephros and metanephros group kidneys were larger than all remaining groups (P < 0.0001). The mesonephros group nephron number was ~40% lower than control values (P = 0.002). Glomerular areas were 26% and 18% larger than the control group in the mesonephros and metanephros groups, respectively (P < 0.001). These data suggest an E7-E9 critical window of cardiovascular and renal development for atenolol. Acute atenolol exposure in E15 embryos showed an increase in mean arterial pressure with all but the highest dose. All doses significantly decreased heart rate.

Orientador: Cristina Antoniali Silva / Banca: Maria Luiza Nunes Mamede Rosa / Banca: Robson Frederico Cunha / Banca: Isabela Almeida Pordeus / Banca: Ronaldo Célio Mariano / Resumo: O objetivo deste trabalho foi avaliar a atividade das glândulas salivares, a mineralização dental e a participação da metaloproteinase de matriz (MMP-9) nesta mineralização em filhotes de ratas espontaneamente hipertensas (SHR) tratadas ou não com atenolol. Ratas SHR e normotensas Wistar foram tratadas com atenolol (100mg/Kg/dia, via oral) durante os períodos de prenhez e lactação. Os grupos controle receberam o mesmo volume de água sem atenolol. O fluxo salivar, induzido por nitrato de pilocarpina, a concentração de proteínas (método de Lowry), a atividade da amilase (método cinético a 405 nm), o peso das glândulas salivares (parótidas, submandibulares e sublinguais), a microdureza do esmalte e da dentina de incisivos e molares e a expressão da MMP-9 (imonuperoxidase) no tecido dental foram comparados entre filhotes de ratas SHR e Wistar tratadas ou não com atenolol. Os resultados obtidos foram submetidos ao teste estatístico mais adequado, paramétrico (ANOVA ou test t de Student's) ou não paramétrico (Kruskal-Wallis), sendo consideradas significativas as diferenças quando p<0,05. Filhotes SHR apresentaram menor fluxo salivar e concentração de proteínas do que filhotes Wistar, mas a atividade da amilase não foi diferente entre os grupos. O peso das glândulas salivares foi semelhante entre filhotes SHR e Wistar...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of the present study was analyzed the salivary activity, the dental mineralization and the role of matrix metalloproteinase-9 (MMP-9) on this mineralization, in pups (30 days) of spontaneously hypertensive rats (SHR) treated, or not treated, with atenolol. Female SHR and normotensive Wistar rats were treated during pregnancy and lactation periods with Atenolol 100mg/Kg/day by oral administration. For the control group, the animals received the same water volume without the drug. The salivary flow rate (stimulated by pilocarpine injection), the protein concentration (Lowry method), salivary amylase activity (kinetic method at 405 nm), the weight of salivary glands (parotid, submandibular and sublingual), the enamel and dentin microhardness of incisors and molars teeth and the matrix metalloproteinase-9 (MMP-9, gelatinase B) localization (imunoperoxidase) in dental tissue were compared between SHR and Wistar pups of female rats treated or not with atenolol. The results were analyzed by parametric (ANOVA or Student’s tests) or non-parametric (Kruskal-Wallis) tests (p<0,05). The salivary flow rate and salivary protein concentration were reduced in SHR pups. There was no alteration in amylase activity between groups. The salivary glands’ weight was not different between SHR and Wistar pups either. Decreased enamel and dentin microhardness were observed in incisors and molar teeth of SHR pups. No alterations in MMP-9 positive staining were observed in predentin and odontoblasts of both groups, however the density of stained ameloblasts cells and external enamel surface were higher in incisors teeth of SHR pups. Atenolol-treated SHR and Wistar rats’ pups showed decrease in submandibular gland weight, in saliva’s flow rate and protein concentration, but no alteration in amylase activity. Atenolol increased enamel and dentin microhardness of incisors teeth of SHR and...(Complete abstract, click electronic address below) / Doutor

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-Graduação em Farmácia. / Made available in DSpace on 2012-10-22T09:17:35Z (GMT). No. of bitstreams: 0 / Hipertensão é a doença cardiovascular com maior prevalência no mundo. Existe ampla evidência que tenha início na infância. A seleção da terapia apropriada depende da causa da doença e da idade da criança. Muitos fatores afetam a escolha de um anti-hipertensivo quando da otimização do tratamento em crianças. Entre eles estão o diagnóstico, a severidade da doença, as complicações, as doenças paralelas, a utilização de outros fármacos e a formulação do medicamento. O manejo da hipertensão em crianças inclui o uso de bloqueadores, inibidores da enzima conversora da angiotensina, bloqueadores de canais de cálcio e diuréticos. A maioria dos fármacos prescritos para crianças não possui forma farmacêutica apropriada pra este fim. A falta extensiva de dados sobre o uso dos antihipertensivos pediátricos aponta para estudos que incluem somente fármacos com algum potencial perigoso descrito na literatura. O atenolol é um fármaco pertencente à classe dos ß bloqueadores. Esta classe de fármacos vem sendo utilizada na pediatria, mesmo estando disponível no mercado somente em apresentações para adultos. O objetivo deste trabalho foi desenvolver e avaliar uma formulação de atenolol em veículo xarope destinado à utilização em ambiente hospitalar. Realizou-se a caracterização da matéria prima. Foi desenvolvida formulação líquida de atenolol utilizando o xarope como veículo. Realizou-se o controle de qualidade da água, seguido das análises físico-químicas e microbiológicas do xarope contendo o fármaco. Estudo da estabilidade do atenolol frente ao calor foi desenvolvido. Padronizou-se o método para doseamento do fármaco em plasma de ratos, assim como a avaliação da eficácia nos animais pela diminuição da freqüência cardíaca. Realizou-se estudo clínico em pacientes internados no Hospital Infantil Joana de Gusmão, com a avaliação da evolução do quadro clínico das crianças. Os resultados farmacocinéticos obtidos experimentalmente em ratos mostraram diferenças significativas do fármaco em veículos distintos, e a inclusão deste medicamento na rotina do Hospital Infantil Joana de Gusmão resultou na melhora dos parâmetros clínicos e controle da sintomatologia das patologias apresentadas pelos pacientes. Hipertension is the cardiovascular illness with most prevalence in the world. Ample evidence exists that has beginning in infancy. The election of the appropriate therapy depends on the cause of the illness and child'age. Many factors affect the choice of an antihypertensive when of the otimization of the treatment in children. Between them they are the diagnosis, the severity, the complications, the illnesses parallel and the use of other drugs. The hipertension treatment in children includes the use of ß blockers, inhibitors of the converting enzyme of the angiotensine, blockers of calcium canals and diuretcs. The majority of the drugs prescribed for children are not available in suitable dosage forms. The extensive lack of data on the use of pediatrics antihypertensives points with respect to studies that only include drugs with some described dangerous potential in literature. Atenolol is a pertaining drug to the class of ß blokckers. This drugs comes being used in the pediatrics, exactly being available in the market only in presentations for adults. The objective of this work was to develop and to evaluate a formularization of atenolol in syrup must destined to the use in hospital environment. It was analysed the characterization of the raw material. Atenolol liquid was developed using the syrup vehicle. The quality control of the water was developed, followed of the analyses microbiological, chemistries and of the syrup contend the drug. Study of the stability of atenolol front to the temperature. Analytical methodology for assay of the drug in mouse's plasma was standardized, as well as the evaluation of the effectiveness in the animals for the reduction of the cardiac frequency. Clinical study in patients interned in the Hospital Joana de Gusmão was studied with the evolution of the clinical of the children. The pharmacokinetics results in rats had experimentally shown significant differences of the same drug with distinct vehicles and the inclusion of this medicine in the Hospital Joana de Gusmão routine in such a way showed improvement of the patients in the clinical parameters, as in the sintomatology of the presented patology.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Propranolol, a first-generation nonselective β-adrenoceptor blocking agent, is commonly used to treat pediatric arrhythmias. Atenolol, relatively long-acting, cardioselective β-adrenoceptor blocking agent, has been successfully used in adults with supraventricular tachycardia (SVT). There is only one report on the use of atenolol in children with SVT, and our report is on the first long-term prospective study to evaluate the use of atenolol in children. A group of 22 children <18 years of age with clinical SVT were enrolled in the study. The tachycardia was documented on electrocardiograms in each case and was confirmed by electrophysiologic studies in some. Once- a-day oral atenolol was started as a monotherapy. Of the 22 children with various types of SVT, 13 (59%) were well controlled on long-term oral atenolol therapy. The effective dose of atenolol ranged between 0.3 and 1.3 mg/kg/day (median effective dose 0.7 mg/kg/day). Five children had some adverse effects. However, none in the successful group of 13 patients required drug discontinuation because of such effects. Once-a-day oral atenolol as a monotherapy is effective and relatively safe for long-term management of SVT during childhood. It is an attractive alternative β- adrenoceptor blocking agent for the management of pediatric arrhythmias.