PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 9700936

Comparative pharmacokinetic study of a floating multiple-unit capsule, a high-density multiple-unit capsule and an immediate-release tablet containing 25 mg atenolol.

N Rouge·E Allémann·M Gex-Fabry·L Balant·E T Cole·P Buri·E Doelker
View original source ↗Export metadata ↓

Abstract

The purpose of this study was to evaluate the possible advantages of floating and high-density dosage forms and their influence on pharmacokinetic parameters. Atenolol was chosen as a model drug because of its poor absorption in the lower gastrointestinal tract. Three formulations containing 25 mg atenolol, a floating multiple-unit capsule, a high-density multiple-unit capsule, and an immediate-release tablet were compared with respect to estimated pharmacokinetic parameters. The two multiple-unit dosage forms were composed of compressed minitablets and had sustained release properties. The bioavailability of the two gastroretentive preparations with sustained release characteristics was significantly decreased when compared to the immediate-release tablet. The floating minitablets seemed to be retained longer in the stomach than the high-density dosage form. The first atenolol concentration detectable in the plasma and the time to peak Tmax were delayed for the floating dosage form. For the parameters Cmax and AUC 0-infinity, the lower limit of the 90% confidence interval was outside the bioequivalence range (0.80-1.25). This study showed that it was not possible to increase the bioavailability of a poorly absorbed drug such as atenolol using gastroretentive formulations. Atenolol absorption was delayed and the maximum plasma concentration was diminished.

Explore related subjects

Adrenergic beta-AntagonistsAdultAtenololCapsulesGastric JuiceHumansMaleTabletsClinical TrialComparative StudyJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

N Rouge, E Allémann, M Gex-Fabry, L Balant, E T Cole, P Buri, E Doelker. 1998. Comparative pharmacokinetic study of a floating multiple-unit capsule, a high-density multiple-unit capsule and an immediate-release tablet containing 25 mg atenolol.. https://doi.org/10.1016/s0031-6865(97)00050-2

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Bayesian sensitivity analysis for unmeasured confounding in observational studies.

We consider Bayesian sensitivity analysis for unmeasured confounding in observational studies where the association between a binary exposure, binary response, measured confounders and a single binary unmeasured confounder can be formulated using logistic regression models. A model for unmeasured confounding is presented along with a family of prior distributions that model beliefs about a possible unknown unmeasured confounder. Simulation from the posterior distribution is accomplished using Markov chain Monte Carlo. Because the model for unmeasured confounding is not identifiable, standard large-sample theory for Bayesian analysis is not applicable. Consequently, the impact of different choices of prior distributions on the coverage probability of credible intervals is unknown. Using simulations, we investigate the coverage probability when averaged with respect to various distributions over the parameter space. The results indicate that credible intervals will have approximately nominal coverage probability, on average, when the prior distribution used for sensitivity analysis approximates the sampling distribution of model parameters in a hypothetical sequence of observational studies. We motivate the method in a study of the effectiveness of beta blocker therapy for treatment of heart failure.

Adrenergic beta-Antagonists↗
PubMed2007

[Polypharmacy, compliance and non-prescription medication in patients with cardiovascular disease in Germany].

BACKGROUND AND OBJECTIVE: The expenses of health insurances are continuously raising. With implementation of evidence-based medicine resulting in polypharmacy, compliance is decreasing and patients as well as physicians are facing unintentional drug interactions. Furthermore the arbitrary use of additional drugs apart from prescribed medication has to be considered. The objective of this study was to analyse polypharmacy, compliance and utilisation patterns for non-prescription medications (OTC) in patients with cardiovascular diseases. METHODS: 100 patients with cardiovascular diseases (45 women, 55 men, 58 - 87 years) were interviewed using a questionnaire. The compliance was determined by the Morisky-Score. RESULTS: 78 % of the patients received more than four pills every day (median 8.34). Most common products were beta-blockers (89 %), ACE-Inhibitors/Sartans (69 %) and aspirin (65 %). Only 52 % of the patients knew the indications of their medication. Although 83 % of the patients claimed to be absolutely compliant concerning their medication, the Morisky-Score revealed a high compliance only in 52 %. The compliance decreased significantly if the number of prescribed medication increased to more than four pills a day. 48 % of the patients took regularly non-prescription products, 35 % more than three additional products daily. Most commonly multivitamins, minerals, herbals and non-steroidal anti-inflammatory drugs were used. This non-prescription medication did not affect the compliance of the patients. CONCLUSIONS: Polypharmacy with more than four pills daily leads to a lower compliance and can therefore influence the implementation of guideline-medicine. Non-prescription medication is widely used and should be considered because of their potential side-effects and drug interactions.

Adrenergic beta-Antagonists↗
PubMed2007

Propranolol blocks chronic risperidone treatment-induced enhancement of spatial working memory performance of rats in a delayed matching-to-place water maze task.

RATIONALE: Atypical antipsychotics improve cognitive function, including working memory, in schizophrenia. Some atypical antipsychotics have been reported to activate the locus coeruleus and induce beta-adrenoceptor antagonist sensitive c-Fos-like immunoreactivity in the prefrontal cortex. MATERIALS AND METHODS: The present study investigated the effects of chronic treatment of rats with risperidone (1 mg kg(-1) day(-1) s.c.), clozapine (10 mg kg(-1) day(-1) s.c.), or acidified saline vehicle control for 2, 4, or 8 weeks on spatial working memory performance in a delayed matching-to-place water maze task with a 60-s inter-trial retention interval with and without acute challenge with propranolol (10 mg/kg i.p.). RESULTS: Treatment with risperidone for 8 weeks, but not 2 or 4 weeks, significantly improved working memory performance. In contrast, treatment with clozapine for up to 8 weeks did not improve working memory. Acute challenge with propranolol blocked the improvement in working memory produced by chronic treatment with risperidone, but had no significant effect on performance in saline- or clozapine-treated animals. CONCLUSIONS: The delayed matching-to-place water maze task may prove valuable in the investigation of the behavioural pharmacology of the cognitive effects of antipsychotic drugs. These data suggest that beta adrenoceptors may contribute to the cognitive effects of chronic treatment with atypical antipsychotics.

Adrenergic beta-Antagonists↗