Different effects of exercise on plasma concentrations of nebivolol, bisoprolol and carvedilol

A Preliminary Investigation on the Effects of Atenolol for Treating Symptoms of Anxiety

INTRODUCTION

Anxiety disorders are among the most commonly diagnosed of psychiatric disorders. Many symptoms of posttraumatic stress disorder are also anxiety-related. Traditional medications used to treat these disorders, such as antidepressants and benzodiazepines, are often ineffective, not well-tolerated, and can be habit forming. An alternative agent is, therefore, needed. Beta-blockers are one class of medication with potential to treat anxiety-related disorders; however, current evidence remains limited and requires further characterization. To this end, this retrospective study aims to present a novel preliminary report on the use of the beta-blocker, atenolol, to potentially treat anxiety-related disorders.

MATERIALS AND METHODS

Ninety-two patients were identified from outpatient military mental health clinics in Okinawa, Japan, who had received atenolol for mental health-related symptoms. Primary measures collected were the rates of patient-reported (1) general beneficial/positive effect of atenolol, (2) adverse effects from atenolol, and (3) preference of atenolol to propranolol. Data were collected from patients who were given binary response options to report their perceived experiences for each primary measure. This study was approved by the Naval Medical Center San Diego Institutional Review Board.

RESULTS

The results showed 86% of patients reporting a positive effect and continuing to take atenolol, including 87% with a diagnosis of posttraumatic stress disorder, 100% with diagnosis of other specified trauma- and stressor-related disorder, and 81% diagnosed with anxiety disorders. In total, 90% of patients denied adverse effects or found the adverse effects tolerable. Additionally, 100% of patients who had previously taken propranolol for anxiety reported that they preferred atenolol.

CONCLUSIONS

The present preliminary observational data suggests that atenolol may be well-tolerated and effective among persons with anxiety disorders. These data also suggest that atenolol may be more effective and better tolerated than propranolol, which is the most commonly prescribed beta-blocker for these conditions; however, more rigorously controlled empirical studies are needed to further substantiate this claim. Despite an overwhelmingly high rate of positive reports from patients' self-evaluations of atenolol treatment for anxiety-related disorders, this early investigation was not placebo-controlled nor double-blinded, and formal outcome measures were not assessed due to a lack of availability. More detailed examinations are needed to further determine whether atenolol is a viable alternative or augmenting agent to propranolol, benzodiazepines, and antidepressants for anxiety disorders and trauma-related disorders.

Nebivolol Desensitizes Myofilaments of a Hypertrophic Cardiomyopathy Mouse Model

Background: Hypertrophic cardiomyopathy (HCM) patients often present with diastolic dysfunction and a normal to supranormal systolic function. To counteract this hypercontractility, guideline therapies advocate treatment with beta-adrenoceptor and Ca²⁺ channel blockers. One well established pathomechanism for the hypercontractile phenotype frequently observed in HCM patients and several HCM mouse models is an increased myofilament Ca²⁺ sensitivity. Nebivolol, a commonly used beta-adrenoceptor antagonist, has been reported to lower maximal force development and myofilament Ca²⁺ sensitivity in rabbit and human heart tissues. The aim of this study was to evaluate the effect of nebivolol in cardiac muscle strips of an established HCM Mybpc3 mouse model. Furthermore, we investigated actions of nebivolol and epigallocatechin-gallate, which has been shown to desensitize myofilaments for Ca²⁺ in mouse and human HCM models, in cardiac strips of HCM patients with a mutation in the most frequently mutated HCM gene MYBPC3.

Methods and Results: Nebivolol effects were tested on contractile parameters and force-Ca²⁺ relationship of skinned ventricular muscle strips isolated from Mybpc3-targeted knock-in (KI), wild-type (WT) mice and cardiac strips of three HCM patients with MYBPC3 mutations. At baseline, KI strips showed no difference in maximal force development compared to WT mouse heart strips. Neither 1 nor 10 μM nebivolol had an effect on maximal force development in both genotypes. 10 μM nebivolol induced myofilament Ca²⁺ desensitization in WT strips and to a greater extent in KI strips. Neither 1 nor 10 μM nebivolol had an effect on Ca²⁺ sensitivity in cardiac muscle strips of three HCM patients with MYBPC3 mutations, whereas epigallocatechin-gallate induced a right shift in the force-Ca²⁺ curve.

Conclusion: Nebivolol induced a myofilament Ca²⁺ desensitization in both WT and KI strips, which was more pronounced in KI muscle strips. In human cardiac muscle strips of three HCM patients nebivolol had no effect on myofilament Ca²⁺ sensitivity.

The effects of high physical activity on pharmacokinetic drug interactions

INTRODUCTION

With the development of new drugs, it is common practice for drug manufacturers to measure their pharmacokinetic parameters. This testing involves the discovery of the absorption, distribution, metabolic, excretory and toxicological properties of drugs. The testing is usually done in non-stressful conditions at rest, however, this does not necessarily tell the entire picture as there is increasing knowledge about the effects that high levels of physical activity can have on the pharmacokinetics of some medications.

AREAS COVERED

This review discusses the alterations that physical activity can have on the absorption, distribution, metabolism and elimination parameters of commonly used medications, and clinical outcomes data are reported when known, demonstrating that an interaction exists between exercise and certain medications. This drug-exercise pharmacokinetic interaction alters the performance of medications especially under conditions where exercise is performed for a long period of time. Particular medications that may be affected are those with a narrow therapeutic dosing range, such as digoxin, theophylline and warfarin. Other important medications include insulin and those administered via a transdermal patch drug delivery system. For this review, a literature search was performed between 1966 and 2010.

EXPERT OPINION

Patients and healthcare providers should be aware that exercise can adversely affect the way some medications are intended to work. Patients taking certain medications should be closely monitored when performing high amounts of physical activity.

The period between beta-blocker use and physical activity changes training heart rate behavior

The Brazilian Society of Cardiology (SBC) proposes that hypertensive subjects who use beta-blockers and practice physical exercises must have their training heart rate (HR) corrected due to the negative chronotropic effect of this drug. Nevertheless, if the physical activity is performed outside of plasmatic half-life, correction may not be necessary. This study investigated the exercise chronotropic response both inside and outside the beta-blocker plasmatic half-life. Nine subjects in use of atenolol or propranolol, and six controls, carried out three walking sessions in three days according to different schedules: EX2 (two hours after drug administration, at the plasmatic peak); EX11 (eleven hours after drug administration, at the end of plasmatic half-life); and EX23 (twenty-three hours after drug administration, outside the plasmatic half-life. The walking sessions were performed on an ergometric treadmill and HR was monitored by a heart rate monitor. During the exercises, mean HRs were 97.2, 108.4 and 109 for EX2, EX11 and EX23, respectively, with the value for EX2 statistically lower than the others (p<0.05). There were no statistical differences in the control group (p>0.05). The study concludes that the attenuation of the positive chronotropic response which occurs during exercise in subjects using beta-blockers, is less evident when the exercise is performed outside the plasmatic half-life of the drug.

Metabolic profile of nebivolol, a beta-adrenoceptor antagonist with unique characteristics

beta-Adrenoceptor antagonists (beta-blockers) have historically been considered an effective and safe option for first-line treatment of hypertension. However, very recently, it has been proposed that beta-blockers should no longer be considered suitable for first-line therapy in the patient with uncomplicated hypertension because of unfavourable morbidity and mortality data. New evidence from recent clinical studies of nebivolol, a third-generation highly selective beta(1)-blocker with additional endothelial nitric oxide (NO)-mediated vasodilating activity, confirms previous findings that this drug differs from other beta-blockers. The combined mechanisms of beta-adrenoceptor antagonism and NO-mediated vasodilation may potentiate the blood pressure-lowering effect of this agent, and confer a broader favourable metabolic profile, which may be clinically relevant for hypertensive patients. The antioxidant properties of nebivolol and its neutral or even favourable effects on both carbohydrate and lipid metabolism are well documented. These properties consistently differentiate nebivolol from nonvasodilating beta-blockers such as atenolol, metoprolol or bisoprolol. Therapeutic indications for beta-blockers include a wide range of co-morbidities found in hypertensive patients, including ischaemic heart disease, tachyarrhythmias and heart failure. Given that the majority of hypertensive patients require more than one drug to control blood pressure, the multiple mechanisms of action and favourable metabolic profile of nebivolol could make it an alternative therapeutic option for hypertensive patients requiring beta-adrenoceptor therapy.

Comparing Beta-Blocking Effects of Bisoprolol, Carvedilol and Nebivolol

OBJECTIVE

Bisoprolol, carvedilol and nebivolol have been shown to be effective in the treatment of heart failure. However, the beta-blocking effects of these drugs have never been compared directly.

METHODS

Therefore, we performed a randomized, double-blind, placebo-controlled, cross-over trial in 16 healthy males. Subjects received 10 mg bisoprolol, 50 mg carvedilol, 10 mg nebivolol and placebo on the first morning followed by 5 mg bisoprolol once daily, 25 mg carvedilol twice daily, 5 mg nebivolol once daily and placebo for 1 week. Heart rate and blood pressure were measured at rest and exercise 3 and 24 h following intake of the first dose, and immediately before and 3 hours following intake of the last dose of each drug. In addition, effects of the drugs on nocturnal melatonin release were determined, and quality of life (QOL) was evaluated.

RESULTS

Heart rate at exercise was decreased at 3 h following intake of the first single dose of each drug by bisoprolol (-24%), carvedilol (-17%) and nebivolol (-15%), and at 24 h following intake of the respective last dose of each drug following 1 week of chronic administration by bisoprolol (-14%), carvedilol (12 h; -15%) and nebivolol (-13%) (p < 0.05 in all cases). Thus, trough-to-peak-ratios at long-term were as follows: Bisoprolol, 58%; carvedilol (12 h), 85%; nebivolol, 91%. Nocturnal melatonin release was decreased by bisoprolol (-44%, p < 0.05) whereas nebivolol and carvedilol had no effect. QOL with carvedilol was slightly but significantly lower than with the other drugs, whereas bisoprolol and nebivolol did not alter QOL.

CONCLUSIONS

These data show that peak beta-blocking effects of bisoprolol appear stronger than those of nebivolol and carvedilol. On the other hand, nebivolol exerts the highest trough-to-peak-ratio. However, beta-blocking effects of all the three drugs are similar at trough. Only bisoprolol but neither nebivolol nor carvedilol decreased nocturnal melatonin release, a feature which might cause sleep disturbances. Finally, only carvedilol slightly decreased QOL, whereas nebivolol and bisoprolol did not affect QOL. We conclude that different beta-blockers may exert clinically relevant different effects.

Nebivolol

Nebivolol is a third-generation beta-adrenoceptor antagonist. It differs from other beta-adrenoceptor antagonists as it combines highly selective beta(1)-adrenoceptor antagonist properties with nitric oxide-mediated vasodilatory actions and beneficial effects on endothelial function. Nebivolol is approved in Europe and several other countries for the treatment of essential hypertension and in Europe for the treatment of stable mild or moderate chronic heart failure (CHF) in addition to standard therapies in elderly patients aged >or=70 years. Nebivolol is an effective antihypertensive agent and is well tolerated in patients with hypertension. The drug also effectively decreased the composite endpoint of mortality and cardiovascular hospital admission in elderly patients with CHF and was generally well tolerated in this population. Nebivolol should be considered as an alternative first-line treatment option for patients with uncomplicated mild to moderate essential hypertension and in elderly patients with CHF.