Objective: To assess the effect of Carvedilol in reducing portal pressure estimated non-invasively by studying Doppler ultrasound waveforms (DUS) and hepatic vein Damping Index (DI). Study Design: Quasi-experimental study. Place and Duration of Study: Department of Medical ICU in collaboration with Department of Radiology, JPMC, over a period of 6 months (June 1st to 30th November, 2008). Methodology: Of the enrolled 65 patients, 47 patients (33 males and 14 females) completed the study. The mean age was 47.4 years. Cirrhotic patients of Hepatitis B, C, D (delta), B and C combined, B and D combined with varying degrees of portal hypertension were included in the study. Cirrhotic patients with bronchial asthma, congestive heart failure, Insulin dependent Diabetes, portal vein thrombosis and hepatorenal syndrome were excluded from the study. The patients were examined by color flow Doppler of the right hepatic vein before and after administration of Carvedilol. Their waveforms and Damping Index (DI) were recorded and compared by Wilcoxon signed ranks test through SPSS version 12.0. Responders were described as those showing a positive change in wave forms or a decrese of 0.10 or more in DI. Results: Of the 47 patients, 30 (63%) showed a positive response and 10 (21%) showed no favorable response to Carvedilol, while 7 (14%) patients showed deterioration. The mean DI on DUS dropped from 0.62 to 0.41 in responders after treatment, while in the non-responders it ranged between 0.42 and 0.57. Conclusion: Ultrasonography Carvedilol reduced portal pressure of cirrhotic patients, as measured indirectly by the damping index of hepatic waveform by Doppler.

BACKGROUND: Autonomic alterations in heart failure are associated with an increase in morbimortality. Several noninvasive methods have been employed to evaluate the sympathetic function, including the Meta-Iodobenzylguanidine (123I-MIBG) scintigraphy imaging of the heart. OBJECTIVE: to evaluate the cardiac sympathetic activity through 123I-MIBG scintigraphy, before and after three months of carvedilol therapy in patients with heart failure and left ventricular ejection fraction (LVEF) < 45%. PATIENTS AND METHODS: Sixteen patients, aged 56.3 +/- 12.6 years (11 males), with a mean LVEF of 28% +/- 8% and no previous use of beta-blockers were recruited for the study. Images of the heart innervation were acquired with 123I-MIBG, and the serum levels of catecholamines (epinephrine, dopamine and norepinephrine) were measured; the radioisotope ventriculography (RIV) was performed before and after a three-month therapy with carvedilol. RESULTS: Patients' functional class showed improvement: before the treatment, 50% of the patients were FC II and 50% were FC III. After 3 months, 7 patients were FC I (43.8%) and 9 were FC II (56.2%), (p = 0.0001). The mean LVEF assessed by RIV increased from 29% to 33% (p = 0.017). There was no significant variation in cardiac adrenergic activity assessed by 123I-MIBG (early and late resting images and washout rate). No significant variation was observed regarding the measurement of catecholamines. CONCLUSION: The short-term treatment with carvedilol promoted the clinical and LVEF improvement. However, this was not associated to an improvement in the cardiac adrenergic activity, assessed by 123I-MIBG scintigraphy, as well as the measurement of circulating catecholamines.

The objective of the present study was to employ suitable adsorbent with free flowing characteristics for improving the stability and physical properties of solid lipid nanoparticles (SLN) for oral administration. Stearic acid based nanoparticles of carvedilol phosphate were fabricated by solvent emulsification evaporation technique in sodium taurocholate solution prepared in pH 7.2 buffers (I-KH(2)PO(4)/NaOH or II-NaH(2)PO(4)/Na(2)HPO(4)) with 1% polyvinyl alcohol. Nanoparticles were then adsorbed by passing the nanodispersion through a Neusilin US2 (adsorbent) column. Interestingly, scanning electron microscopy revealed round deformed and even collapsed nanoparticles in Buffer-I and discrete spherical to ellipsoidal nanoparticles in Buffer-II which indicates the inability of nanoemulsion to crystallize and form SLN in Buffer-I. The successful formation of SLN in Buffer-II was confirmed by differential scanning calorimetry and X-ray diffraction. The retention of SLN from the nanodispersion by adsorption on the adsorbent imparted good flow property and resulted in a marked stability improvement of the formulation in terms of drug retention efficiency and release profile as compared to the simple nanosuspension. In conclusion, the adsorbent technology would be instrumental in imparting additional features to the existing conventional colloidal system for pharmaceutical application which would ease the process of capsule filling at industrial scale, simplify the handling of formulations by patients and can significantly improve the shelf life of the product for a longer period of time as compared to liquid formulations.

Background: Cardioplegia and reperfusion of the myocardium may be associated with cardiomyocyte apoptosis and subsequent myocardial injury. To establish a pharmacologic strategy for the prevention of these events, this study aimed to verify the reliability of our human cardiac model and to evaluate the antiapoptotic properties of the nonselective beta-blocker carvedilol during simulated cardioplegia and reperfusion ex vivo.Methods: Cardiac biopsies were retrieved before induction of cardiopulmonary bypass from the auricle of the right atrium of patients undergoing elective coronary artery bypass grafting. Biopsies were exposed to ex vivo conditions of varying periods of cardioplegia/reperfusion (30/10 minutes, 60/20 minutes, 120/40 minutes). Group I was the untreated control (n = 15), group II was the treated control (cardioplegia/reperfusion, n = 15), and group III was the experimental group (cardioplegia/reperfusion plus carvedilol, n = 15). Immunostaining for antibodies to activated caspase 3 and poly(ADP-ribose) polymerase 1 (PARP-1) cleavage was used to detect apoptosis.Results: The percentage of apoptotic cardiomyocytes was significantly lower (P < .05) in group I than in group II, revealing a time-dependent increase. In group III, carvedilol treatment suppressed apoptosis significantly (P < .05).Conclusion: Carvedilol significantly suppresses apoptosis in our ex vivo setting. This finding warrants further studies to evaluate the potential beneficial effects of carvedilol in suppressing ischemia/reperfusion injury in clinical settings.

Study OBJECTIVE: To assess the impact of paroxetine coadministration on the stereoselective pharmacokinetic (PK) properties of carvedilol. Design: Prospective, randomized, 2-phase crossover. Setting: The University of Michigan General Clinical Research Unit and Michigan Clinical Research Unit. Participants: Twelve healthy volunteers aged 18 to 45 years, male and female, receiving no treatment with prescription or nonprescription medications. Interventions: Participants received single dose oral carvedilol (12.5 mg) with and without coadministration of immediate-release paroxetine (10 mg orally twice daily), in random order. Blood samples were collected at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, 12, and 24 hours post-carvedilol dose for determination of R and S carvedilol plasma enantiomer concentrations by high pressure liquid chromatography. Measurements and Main RESULTS: Pharmacokinetic (PK) parameters were calculated for each enantiomer by noncompartmental methods and compared between study phases by analysis of variance (ANOVA) controlling for study phase order and subject, with Tukey's studentized range test post hoc. Area under the concentration-time curve (AUC) increased significantly with paroxetine coadministration, approximately 2.5-fold and 1.9-fold for the R and S enantiomers, respectively. R/S AUC ratio increased significantly, from approximately 2.3 to 3.0. Individual increases in enantiomeric AUCs with paroxetine coadministration ranged from 0% to 571% and changes in R/S ratio ranged from -8% to 108%. Heart rate, P-R interval, and blood pressure were monitored and no clinically significant changes in carvedilol effects were noted. Conclusion. This study demonstrated a PK drug-drug interaction between paroxetine and carvedilol, with considerable interparticipant variability in carvedilol PK parameters and magnitude of drug interaction. Stereoselectivity of carvedilol metabolism is preserved with paroxetine coadministration, and R/S AUC ratio generally widens. Although this drug interaction could potentially increase adrenergic antagonism and have significant clinical effects in patients, these effects were not seen in our healthy volunteer participants.

Background: Carvedilol is a nonselective beta-adrenoceptor and selective alpha(1)-adrenoceptor blocker and is widely used in the treatment of patients with hypertensive and/or chronic heart failure because, unlike classic beta-blockers, this drug has additional endothelium-dependent vasodilatory effects. We evaluated the effects of oral administration of carvedilol on cardiopulmonary resuscitation (CPR) in a rat model of cardiac arrest (CA) induced by airway obstruction. Methods: Twenty-four rats were randomly assigned to 2 groups: control group (no medication) and treatment group (oral administration of carvedilol [10 mg/kg/d] for 5 days) (n = 12 per group). All the animals were anesthetized, and CA was induced by obstructing the airway. Three minutes after CA, the animals were revived by administering CPR. The rate of chest compressions (CCs) was 240 to 260 CCs/min and the depth of CCs was adjusted to maintain the diastolic arterial blood pressure between 25 to 30 mm Hg in both groups. Epinephrine (0.02 mg/kg) was administered after 5 minutes of CPR. No other therapy was administered before, during, or after CA. Results: The time interval between airway obstruction and CA in the treatment group was significantly longer than in the control group (230 +/- 27 vs 203 +/- 24 seconds; P < 0.05). The rate of return of spontaneous circulation in the treatment group was significantly higher than in the control group (92% vs 50%; P < 0.05). Acidosis and increased glucose and tumor necrosis factor-alpha concentrations in the treatment group were significantly lower than in the control group. Conclusions: The results of our study showed that rats that had been administered oral carvedilol for several days were more resistant to CA induced by airway obstruction, and when CA did occur, were more likely to be resuscitated. These findings suggest that carvedilol may prolong the safe ischemic time induced by respiratory failure.

Carvedilol is a beta- antagonist with strong antioxidant effect in lipids, proteins and superoxide production protecting biological membranes from oxidative stress. We hypothesised a possible therapeutical application of carvedilol in Familial Amyloidotic Polyneuropathy (FAP), a neurodegenerative disease caused by deposition of transthyretin (TTR) amyloid fibrils. Oxidative stress, apoptosis and inflammation related to aggregation of nonfibrillar and fibrillar transthyretin (TTR) have been detected both in pre-symptomatic and symptomatic stages of the disease, respectively. In this study we show by semi-quantitative immunohistochemistry and western blot analysis that administration of carvedilol to a transgenic mouse model of FAP influences the expression of oxidative and apoptotic biomarkers usually associated with TTR deposition, namely oxidation products such as HNE and 8-OHdG, and markers of ER stress. Most important, carvedilol treatment significantly reduced TTR aggregates in as much as 50%. We also observed that carvedilol rescues a mice neuroblastoma cell line from death induced by TTR oligomers, by decreasing activation of BiP and other ER stress biomarkers. Since carvedilol has no effect on TTR aggregation "in vitro", this finding points for the "in vivo" modulation of TTR aggregation by oxidative stress and apoptosis and prompts for the use of this safe drug in prophylactic and therapeutical measures in the FAP population.

Carvedilol is a beta-adrenoceptor antagonist used for treating chronic heart failure (CHF). Two clinical studies were conducted to evaluate the population pharmacokinetics and pharmacodynamics of R- and S-carvedilol, and associated covariates, in patients with CHF. Fifty-eight patients (male=45, female=13) with New York Heart Association class I-IV CHF were enrolled in two clinical studies. R- and S-carvedilol concentrations were measured using HPLC at steady-state after oral administration of carvedilol at 1.25-20 mg o.d. or b.i.d. The data from both studies were used to estimate the population pharmacokinetic parameters and covariates using the nonlinear mixed effects model program. For 40 patients evaluated in one clinical study, the cytochrome P450 (CYP)2D6 *1, *10, and *5 genotypes were determined using allele-specific primer PCR, and individual patients' oral clearance (CL/F) of both enantiomers were estimated by the empirical Bayes method. A one-compartment model with a first-order absorption rate was established, in which body weight and alpha(1)-acid glycoprotein were significant covariates. Individual CL/F values for carvedilol were significantly lower in Japanese CHF patients with the CYP2D6 *1/*5, *5/*10 and *10/*10 genotypes. Estimation of the population pharmacokinetic parameters and their covariates for each enantiomer in Japanese patients with CHF showed that the CL/F values for R- and S-carvedilol were dependent on body weight, alpha(1)-acid glycoprotein, and CYP2D6 genotype. Prediction of exposure to free plasma carvedilol is important for dosage adjustment of beta-blocker therapy in patients with CHF.

There is an evident need for solid oral dosage forms allowing patients' tailor-made dosing due to variations in metabolization or small therapeutic indexes of drug substances. The objective of this work is the development of a device equipped with a novel solid dosage form, containing carvedilol as model drug, for the delivery of monolithical drug carriers in individual doses. The device was developed and constructed enabling an exact feed rate and dose adjustment by a cutting mechanism. A twin-screw extruder was used for producing cylindrical solid dosage forms. Divided doses were characterized by mass variation, cutting behavior and drug dissolution in order to investigate their applicability for practical use. Different formulations could be extruded obtaining straight cylindrical rods, which are divisible in exact slices by using the novel device. Forces below 20N were needed to divide doses which comply with pharmacopoeial specification "conformity of mass". The developed formulations exhibit a sustained release of carvedilol within a range from 7 up to 16h. A novel system consisting of a device and a cylindrical dosage form was developed. Patients' individual doses can be applied as monolithical solid dosage forms for oral use.

PURPOSE Treatment of breast cancer with trastuzumab is complicated by cardiotoxicity in up to 34% of the patients. In most patients, trastuzumab-induced cardiotoxicity (TIC) is reversible: left ventricular ejection fraction (LVEF) improves after trastuzumab withdrawal and with, or sometimes without, initiation of heart failure (HF) therapy. The reversibility of TIC, however, is not foreseeable, and identification of patients at risk and of those who will not recover from cardiac dysfunction is crucial. The usefulness of troponin I (TNI) in the identification of patients at risk for TIC and in the prediction of LVEF recovery has never been investigated. PATIENTS AND METHODS In total, 251 women were enrolled. TNI was measured before and after each trastuzumab cycle. LVEF was evaluated at baseline, every 3 months during trastuzumab therapy, and every 6 months afterward. In case of TIC, trastuzumab was discontinued, and HF treatment with enalapril and carvedilol was initiated. TIC was defined as LVEF decrease of > 10 units and below 50%. Recovery from TIC was defined as LVEF increase above 50%. Results TIC occurred in 42 patients (17%) and was more frequent in patients with TNI elevation (TNI+; 62% v 5%; P < .001). Twenty-five patients (60%) recovered from TIC. LVEF recovery occurred less frequently in TNI+ patients (35% v 100%; P < .001). At multivariate analysis, TNI+ was the only independent predictor of TIC (hazard ratio [HR], 22.9; 95% CI, 11.6 to 45.5; P < .001) and of lack of LVEF recovery (HR, 2.88; 95% CI,1.78 to 4.65; P < .001). CONCLUSION TNI+ identifies trastuzumab-treated patients who are at risk for cardiotoxicity and are unlikely to recover from cardiac dysfunction despite HF therapy.

Patients with cirrhosis develop varices at a rate of 5% per year, and a third of patients with high-risk varices will bleed. The mortality associated with variceal haemorrhage is typically 20%, and still exceeds that of myocardial infarction. Current options to prevent the first variceal bleed include noncardioselective beta-blockers or variceal band ligation. In patients with medium-to-large esophageal varices, both therapies reduce the risk of bleeding by 50% or more. The choice of therapy should take into account patient choice and local availability; although for most patients drug therapy is the preferred first-line treatment. There has been recent interest in carvedilol, with promising initial data. Further studies are necessary before universal recommendation. There is no role for drug therapy in patients without varices, and the use of beta-blockers for patients with small varices is controversial.

BACKGROUND: Currently there are several types of interventions for the treatment of heart failure (HF). Among these are beta-blocker therapy (BB) and physical training (PT). However, the effects of the combination of these therapies are poorly studied. OBJECTIVE: To investigate the effects of BB treatment with metoprolol (M) and carvedilol (C) associated with PT in mice with HF. METHODS: We used a genetic model of sympathetic hyperactivity-induced heart failure in mice. Initially, we divided the HF animals into three groups: sedentary (S); trained (T); treated with M (138 mg/kg) (M); or C (65 mg/kg) (C). In the second part, we divided the groups into three subgroups: sedentary (S); trained and treated with M (TM); and trained and treated with C (CT). The PT consisted of aerobic training on a treadmill for 8 weeks. Exercise tolerance was assessed by maximal graded test, and fractional shortening (FS) was assessed by echocardiography. Cardiomyocyte diameter and collagen volume fraction were evaluated by histological analysis. Data were compared by one way ANOVA and post hoc Duncan test. The significance level was set at p < 0.05. RESULTS: As to FS and cardiac remodeling, we found that, in isolation, T, M, and C showed an improvement of the variables analyzed. As to therapy combination, after the intervention period, we observed an increase in exercise tolerance in MT and CT (43.0% and 33.0% respectively). There was also a reduction in cardiomyocyte diameter (10.0% and 9.0% respectively) and in collagen volume fraction (52.0% and 63.0%) after the intervention. However, only CT significantly improved FS. CONCLUSION: The association of PT with M or C therapies provided benefits on cardiac function and remodeling in HF mice.

To test the hypothesis that nonselective blockade of adrenergic receptor (AR) subtypes is superior to selective blockade of AR subtypes in suppressing left ventricular (LV) remodeling induced by hypertension. Sixty-four spontaneously hypertensive rats (SHR) were randomly divided into four groups: bisoprolol-treated, propranolol-treated, carvedilol-treated and no treatment groups (n=16, each). Sixteen Wistar-Kyoto (WKY) rats served as a control group. Echocardiography and cardiac catheterization were carried out to record the mitral flow velocity ratio of E wave to A wave (E/A), LV mass index (LVMI), maximal rising (dp/dt(max)) and falling (-dp/dt(max)) rate of the LV pressure and LV relaxation time constant (tau). The mRNA and protein expression levels of AR, protein kinase(PK) and G-protein subtypes, intracellular free calcium (Ca(2+)) concentration and cardiocyte apoptoisis rate were determined. Three drug-treated groups showed higher velocity ratio of E wave to A wave (E/A) and -dp/dt(max) and lower systolic blood pressure (SBP), LVMI, tau, apoptosis rate and intracellular free Ca(2+) concentration than the no treatment group. The mRNA expression levels of AR-alpha(1B) in the carvedilol group were significantly lower than the other two drug-treated groups. The mRNA expression levels of AR-beta(1), AR-beta(2) and Gsalpha were significantly higher in the three drug-treated groups than in the no treatment group, with the expression levels of AR-beta(2) being the highest in the carvedilol-treated group. The protein expression levels of PKA and PKC subtype alpha and delta were lower in the three drug-treated groups than in the no treatment group. Overall blockade of AR subtypes is not superior to selective blockade of AR subtypes in suppressing LV remodeling in SHR. Although carvedilol is the most effective in attenuating cardiocyte apoptosis, normalizing AR-alpha(1B) and Gsalpha expression and increasing AR-beta(2) expression.Hypertension Research advance online publication, 29 July 2010; doi:10.1038/hr.2010.121.

At present only bisoprolol, metoprolol succinate, nebivolol, and carvedilol are considered to be beta adrenoblockers with proven efficacy relative to course and prognosis of chronic heart failure (CHF). However in real clinical practice most patients continue to receive preparations which are not recommended for application. Therefore we have conducted this study in order to assess efficacy of switching ambulatory patients from therapy with "not recommended" beta adrenoblockers to bisoprolol which is recommended for the treatment of CHF. We recruited 35 patients with stable class II-III CHF on standard therapy which included beta adrenoblockers not recommended for the treatment of CHF. In all patients at baseline and after 6 months of therapy we assessed clinical status, quality of life with the Minnesota questionnaire and visual analog scale, performed 6 min walk test and echocardiography for evaluation of left ventricular (LV) ejection fraction (EF) and measured level of N terminal fragment of pro brain natriuretic peptide in blood serum. Switching patients from "not recommended" beta adrenoblockers to bisoprolol was associated with significant improvement of clinical status with increase of 6 min walk distance, betterment of parameters of quality of life, and significant rise of LV EF combined with lowering of mean CHF functional class (all <0.01 compared with baseline). There was no significant dynamics of NT proBNP level in the whole group but in the subgroup with NT proBNP values above median significant lowering we noted its significant lowering (<0,05). No significant association between dynamics of main clinico-laboratory parameters and decrease of heart rate was observed. Switch of patients with moderate CHF to bisoprolol from therapy with beta adrenoblockers not recommended for application in this disease was associated with improvement of quality of life, clinical status, and LV systolic function. This was combined with lowering of initially elevated NT proBNP level irrespective of changes of heart rate.

Objective: To report a case of fatal toxic epidermal necrolysis associated with carvedilol treatment. Case summary: Two days after the initiation of carvedilol treatment, a 70-year old woman presented with skin eruptions in the form of maculous rash with blisters that rapidly progressed to epidermal necrolysis. Although the suspected drug was withdrawn, the reaction was extremely rapid in its development with fatal outcome. Discussion: Carvedilol is not a drug commonly associated with TEN. To our knowledge there are no cases of carvedilol related TEN reported in the literature. Conclusion: Because of the close temporal relationship between the initiation of carvedilol treatment and the appearance of skin eruptions, and because carvedilol was the only new medication the patient had taken, the etiology of TEN was most likely a reaction to this drug. Physicians should be aware of this extremely rare but serious ADR.

The case of woman with dysfunction of left ventricle (LV) possible due to Hodgkin's lymphoma treatment and following myocarditis is presented. Triple therapy with carvedilol, ramipril and spironolactone was continued to prevent further LV remodeling. During 3-years follow-up repeated echocardiographic examinations revealed gradual improvement of LV function and clinical condition of the patient. Results of current studies suggest benefits of early implementation of aldosterone antagonist therapy in addition to ACE-inhibitors/angiotensin receptors blockers and beta-blockers in patients with chronic heart failure. Kardiol Pol 2010; 68, 7: 810-813.

Objective Heart failure is one of the most serious complications in Duchenne muscular dystrophy (DMD). Beta-blocker medication is known to improve the prognosis of chronic heart failure of adults, but its efficacy and safety for DMD patients has not been fully assessed. Thus we conducted a multicenter open trial. Methods Fifty-four DMD patients participated; 41 received carvedilol (BB group) and 13 did not (non BB group). All patients with an ejection fraction of less than 50% received angiotensin-converting enzyme inhibitor. Then, patients in BB group were started on carvedilol. The mean maintenance dose of carvedilol in BB group was 7.85+/-2.80 mg/day. Clinical signs and cardiac function were monitored regularly and statistical analysis was done. Results The survival rate free from primary endpoints (death, deterioration of heart failure and severe arrhythmia) was higher in the BB group. The survival rate free from all-cause death was also higher in the BB group, although not significantly higher. Patients with primary endpoints received lower maintenance doses of carvedilol and presented higher mean heart rates (HR) during the observation period. In the BB group, mean HR at enrollment and the reduction of mean HR were correlated with the change of ejection fraction. Although serious adverse events were rare during the introduction of carvedilol, patients with advanced cardiac dysfunction required a longer period for up-titration and frequently presented with minor complaints. Conclusion The present study suggests that carvedilol is relatively safe and can prevent cardiac events even in patients with DMD.

The response to beta blockers in patients with heart failure could be associated with the genotype of drug-metabolizing enzymes and/or drug targets. The purpose of the present study was to determine whether specific genetic polymorphisms in ADRB1 (encoding the beta1-adrenergic receptor), CYP2D6, and UGT1A1 correlated with dose of, or response to, metoprolol or carvedilol treatment in patients with heart failure. A cohort of patients with heart failure (n = 93), characterized as responders or nonresponders to metoprolol (n = 19) or carvedilol (n = 74) therapy, was retrospectively identified. Individual genotyping was performed for a panel of polymorphisms in the ADRB1, CYP2D6, and UGT1A1 genes. Univariate and multivariate analyses were performed to compare the genotype to the metoprolol or carvedilol response status and dose. A nonresponse was identified in 10 of 19 patients taking metoprolol and 32 of 74 patients taking carvedilol. None of the polymorphisms in ADRB1, CYP2D6, and UGT1A1 were associated with a response or nonresponse. However, a significant relation between the carvedilol (but not metoprolol) dose and the ADRB1 and CYP2D6 genotype was observed. Patients homozygous for the ADRB1 389Gly variant or who were CYP2D6 poor metabolizers achieved a significantly higher dose of carvedilol (p = 0.01 and p = 0.02, respectively). In conclusion, polymorphisms in ADRB1, CYP2D6, and UGT1A1 were not associated with a response to metoprolol or carvedilol therapy in our cohort of patients with heart failure. The ADRB1 and CYP2D6 genotype, alone and in haplotype, were significantly associated with the dose of carvedilol.

Abstract Objectives The role of vascular sympatholytic activity of carvedilol in its antihypertensive effect in N(G)-nitro-l-arginine methyl ester (L-NAME) hypertensive rats was assessed by means of enantioselective pharmacokinetic-pharmacodynamic (PK-PD) modelling. Methods Male Wistar rats were randomly divided into two groups: control rats received tap water to drink for 2 weeks while L-NAME rats received L-NAME solution to drink for 2 weeks. The effects of carvedilol (1 and 5 mg/kg i.v.) on blood pressure, heart rate and blood pressure variability were recorded. Enantioselective carvedilol plasma pharmacokinetics were studied by means of traditional blood sampling. The relationship between carvedilol concentrations and their hypotensive and bradycardic effects was established by means of PK-PD modelling. Vascular sympatholytic activity of carvedilol was assessed by the estimation of drug effects on low frequency blood pressure variability by means of spectral analysis. Key findings A dose-dependent increase in volume of distribution, as well as a greater volume of distribution and clearance of S-carvedilol as compared with the R-enantiomer was found in both experimental groups. Although the PK-PD properties of the S-carvedilol chronotropic effect were not altered in L-NAME rats, hypertensive rats showed greater potency and efficacy to the carvedilol hypotensive response. Greater potency of carvedilol for inhibition of sympathetic vascular activity was found in L-NAME rats. Conclusions Carvedilol showed enantioselective non-linear pharmacokinetic properties in both groups. An enhanced hypotensive activity of carvedilol was found in L-NAME hypertensive rats compared with control rats, which may be explained by the greater potency of carvedilol for sympathetic vascular tone inhibition.