Oral Administration Of Propranolol Research Articles

Systemic administration of propranolol reduces bone resorption and inflammation in apical periodontitis of chronically stressed rats.

To evaluate the effect of systemic administration of propranolol on the severity of apical periodontitis (AP) in chronically stressed rats. Twenty-four 70-day-old male Wistar rats (Rattus norvegicus, albinus) were distributed into three groups (n = 8): rats with AP without stressful conditions (AP-Control), rats with AP and submitted to a chronic unpredictable stress (CUS) protocol (AP + S) and rats with AP and submitted to a CUS protocol treated with propranolol (AP + S + PRO). Stress procedures were applied daily until the end of the experiment. After 3 weeks of CUS, AP was induced in all groups by exposing the pulpal tissue of mandibular and maxillary first molars to the oral environment. Propranolol treatment was administered orally once a day for the entire period of the experiment. Rats were sacrificed at 42 days, and the blood was collected for stress biomarkers serum dosage by multiplex assay. Mandibles were removed and submitted to microtomography and histopathological analyses. Periapical tissue surrounding the upper first molar was homogenized and subjected to RT-PCR analysis to evaluate the mRNA expression of RANKL, TRAP and OPG. Parametric data were assessed using one-way ANOVA followed by Tukey's test while the nonparametric data were analysed by the Kruskal-Wallis followed by Dunn's test. Significance level was set at 5% (p < .05) for all assessed parameters. Micro-CT revealed statistically significant differences in bone resorption which was greater in the AP + S group (p < .05), but no differences were observed between the Control and AP + S + PRO groups (p > .05). The AP + S + PRO group had a lower intensity and extent of inflammatory infiltrate compared to the AP + S group with smaller areas of bone loss (p < 0.05). The gene expression of RANKL and TRAP was significantly higher in the stressed group AP + S compared to the control group (p < .05), and a significantly higher OPG expression was observed in AP + S + PRO compared to the AP + S group (p < .05). Oral administration of propranolol had a significant effect on the AP severity in stressed rats, suggesting an anti-inflammatory effect and a protective role on bone resorption of AP in stressed animals. Further research is necessary to fully comprehend the underlying mechanisms.

Compromised trigemino-coerulean coupling in migraine sensitization can be prevented by blocking beta-receptors in the locus coeruleus

BackgroundMigraine is a disabling neurological disorder, characterized by recurrent headaches. During migraine attacks, individuals often experience sensory symptoms such as cutaneous allodynia which indicates the presence of central sensitization. This sensitization is prevented by oral administration of propranolol, a common first-line medication for migraine prophylaxis, that also normalized the activation of the locus coeruleus (LC), considered as the main origin of descending noradrenergic pain controls. We hypothesized that the basal modulation of trigeminal sensory processing by the locus coeruleus is shifted towards more facilitation in migraineurs and that prophylactic action of propranolol may be attributed to a direct action in LC through beta-adrenergic receptors.MethodsWe used simultaneous in vivo extracellular recordings from the trigeminocervical complex (TCC) and LC of male Sprague–Dawley rats to characterize the relationship between these two areas following repeated meningeal inflammatory soup infusions. Von Frey Hairs and air-puff were used to test periorbital mechanical allodynia. RNAscope and patch-clamp recordings allowed us to examine the action mechanism of propranolol.ResultsWe found a strong synchronization between TCC and LC spontaneous activities, with a precession of the LC, suggesting the LC drives TCC excitability. Following repeated dural-evoked trigeminal activations, we observed a disruption in coupling of activity within LC and TCC. This suggested an involvement of the two regions’ interactions in the development of sensitization. Furthermore, we showed the co-expression of alpha-2A and beta-2 adrenergic receptors within LC neurons. Finally propranolol microinjections into the LC prevented trigeminal sensitization by desynchronizing and decreasing LC neuronal activity.ConclusionsAltogether these results suggest that trigemino-coerulean coupling plays a pivotal role in migraine progression, and that propranolol’s prophylactic effects involve, to some extent, the modulation of LC activity through beta-2 adrenergic receptors. This insight reveals new mechanistic aspects of LC control over sensory processing.

Development of a Hydroxypropyl-β-Cyclodextrin-Based Liquid Formulation for the Oral Administration of Propranolol in Pediatric Therapy.

Propranolol (PPN) is widely used in children to treat various cardiovascular diseases. The availability of a suitable PPN solution should avoid recourse to extemporaneous preparations of unknown/limited stability, as commonly made in hospital pharmacies. However, the development of pediatric PPN solutions is hindered by their instability to light and stability at pH ≈ 3, bitter taste, and the need to improve palatability and avoid co-solvents, flavoring agents, or preservatives that are potentially toxic. In this study, cyclodextrin (CD) complexation has been exploited to develop a safe, stable, and palatable oral pediatric solution of PPN. An initial screening among various CDs allowed us to select HPβCD for its good complexing ability and no toxicity. Drug-HPβCD physical mixtures or co-ground systems (1:1 or 1:2 mol:mol) were used to prepare 0.2% w/v drug solutions. Photo stability studies evidenced the protective effect of HPβCD, revealing a reduction of up to 75% in the drug degradation rate after 1 h of exposure to UV radiation. Storage stability studies showed unchanged physical-chemical properties and almost constant drug concentration after 6 months and under accelerated conditions (40 °C), despite the less aggressive pH (≈5.5) of the solution. The electronic tongue test proved that the HPβCD taste-masking properties improved the formulation palatability, with a 30% reduction in drug bitterness.

Effects of oral propranolol on the resistive and pulsatility indices of major abdominal vasculatures in domestic short-haired cats.

No study has been performed regarding the effects of oral administration of propranolol on pulse-wave spectral Doppler indices of major abdominal vessels in healthy adult cats. The objective of this study was to assess the pulse-wave spectral Doppler indices of abdominal aorta, caudal vena cava, and portal vein in clinically normal adult domestic short-haired (DSH) cats, before and after propranolol ingestion. Twenty intact adult client-owned DSH cats were evaluated (10 males and 10 females). A duplex Doppler ultrasonography machine with a 10-MHz frequency linear transducer was used. Peak systolic velocity, end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI), and pressure gradient were measured. All the cats received 1mg/kg of propranolol tablet, and after 2 h, ultrasonography measurements were repeated. The mean RI of the aorta and caudal vena cava significantly decreased in male cats following oral administration of propranolol after 2 h (p = 0.03, p = 0.02). In the caudal vena cava, the PI decreased from 2.98±0.62 to 1.15±0.19 post-propranolol ingestion (p = 0.01). The mean EDV in the caudal vena cava of males and portal veins of females significantly decreased after propranolol ingestion (p = 0.04, p = 0.02). This study showed that propranolol decreased the PI of the aorta and PI and RI of the caudal vena cava in healthy normal cats 2 h post-propranolol ingestion at the dosage of 1mg/kg.

Circulating endothelial cells and endothelial-derived vesicles identification in patients with infantile hemangioma: preliminary results of a prospective cohort study

Circulating Endothelial Cells (CEC) and Circulating Extracellular Vesicles (cEVs) are biological markers of endothelial activity/disfunction and may play a pivotal role in the evolution of IH. Our aims were to detect variations in CEC and cEVs concentration: 1. in IH versus healthy controls; 2. in IH before and after propranolol administration. Twenty-two children (15 cases; 7 controls) from our Department underwent peripheral blood sampling to study CECs, EPCs and EVs via cytofluorimetry. Statistical analyses were performed using XLSTAT ver. 2014.5.03 and GraphPad Prism ver. 8.0. Data were expressed as mean ± standard deviation, median, 5-95th percentile. The number of CEC and HSC was higher among cases than controls, even if not statistically significant. The number of CEC decreased with the evolution of the hemangioma; number of HSC decreased proportionally with the age of the patienst. Number of EVs tended to increase when the CECs decrease and vice-versa in the group of cases but not among controls. Number of CEC and HSC was significantly reduced after oral propranolol administration (p: &lt;0,0001). In conclusion CECs may represent a marker of progression of disease. Propranolol seems to affect the number of CECs and HSCs.

Cyclosporin-A reduced the cytotoxicity of propranolol in HUVECs via p38 MAPK signaling.

Propranolol (PROP) is a nonselective β-adrenergic receptor antagonist used to treat hypertension and cardiac arrhythmias. Oral administration of PROP has recently emerged as a new treatment modality for hemangiomas. However, the side effects of PROP at the cellular level have not been adequately described.The present study investigates and highlights the mechanisms of coupling of the drugs cyclosporin-A (CyA) and PROP on cell proliferation and the occurrence of apoptosis. It also relays the antioxidant effect of PROP on human umbilical vein endothelial cells (HUVECs).HUVECs were treated with CyA and PROP. At 24 hours after treatment, the levels of reactive oxygen species (ROS), cell proliferation, and apoptosis were determined using the ROS kit, MTT assay, and Annexin V staining. In addition, the related proteins of phospho-p38 mitogen-activated protein kinase were determined by western blotting. Subsequently, HUVECs pretreated with CyA or PROP were treated with the p38 inhibitor (SB203580). Finally, the ROS level, cell proliferation, and apoptosis were measured again in both active HUVECs and HUVECs, in which the p38 proteins were inhibited.The combination of CyA and PROP reversed the effect of CyA on cell viability, reduced the ROS level and the cell apoptosis induced by PROP. Moreover, inhibition of p38 protein catalase activity immediately stopped the effect of CyA–propranolol in HUVECs.The effect of the CyA–propranolol combination on HUVECs is associated with the p38 pathway changes, which is proven to be a potential chemotherapeutic agent that minimizes the side effects of PROP in hemangioma therapy.

Propranolol-induced inhibition of unconditioned stimulus-reactivated fear memory prevents the return of fear in humans

Fear memories can be reactivated by a fear-associated conditioned stimulus (CS) or unconditioned stimulus (US) and then undergo reconsolidation. Propranolol administration during CS retrieval-induced reconsolidation can impair fear memory that is specific to the reactivated CS. However, from a practical perspective, the US is often associated with multiple CSs, and each CS can induce a fear response. The present study sought to develop and test a US-based memory retrieval interference procedure with propranolol to disrupt the original fear memory and eliminate all CS-associated fear responses in humans. We recruited 127 young healthy volunteers and conducted three experiments. All of the subjects acquired fear conditioning, after which they received the β-adrenergic receptor antagonist propranolol (40 mg) or placebo (vitamin C) and were exposed to the US or CS to reactivate the original fear memory. Fear responses were measured. Oral propranolol administration 1 h before US retrieval significantly decreased subsequent fear responses and disrupted associations between all CSs and the US. However, propranolol administration before CS retrieval only inhibited the fear memory that was related to the reactivated CS. Moreover, the propranolol-induced inhibition of fear memory reconsolidation that was retrieved by the US had a relatively long-lasting effect (at least 2 weeks) and was also effective for remote fear memory. These findings indicate that the US-based memory retrieval interference procedure with propranolol can permanently decrease the fear response and prevent the return of fear for all CSs in humans. This procedure may open new avenues for treating fear-related disorders.

Clinical effect of propranolol in the treatment of respiratory hemangioma in infants and young children

To study the clinical effect of oral propranolol in the treatment of respiratory hemangioma in infants and young children. A retrospective analysis was performed from the chart review data of children with respiratory hemangioma treated by oral propranolol and diagnosed by bronchoscopy and laryngeal plain enhanced CT/MRI from November 2012 to December 2019. A total of 20 children were enrolled. All children had improvement in the symptoms of laryngeal stridor and dyspnea after oral administration of propranolol for 1-2 days. The median treatment time was 10 months (range 6-12 months). The median follow-up time was 10 months (range 3-15 months). Of the 20 children, 19 (95%) achieved regression of tumor, and 1 (5%) experienced an increase in tumor size during reexamination at 6 months after drug withdrawal and had no recurrence after the treatment with an increased dose of propranolol for 6 months. Only 1 child (5%) had adverse reactions, and 1 child (5%) was still under treatment. Oral propranolol can quickly relieve the symptoms such as dyspnea and achieve tumor regression, with few adverse events, and it is therefore an effective method for the treatment of respiratory hemangioma in infants and young children.

Update in the Treatment of Retinopathy of Prematurity.

Retinopathy of prematurity (ROP) is an alteration in the development of the immature retina vascularization that frequently occurs in premature infants and is one of the leading causes of childhood blindness worldwide. In threshold stage retinopathy, laser photocoagulation is the standard treatment, particularly in those located in zone II. However, this therapy destroys parts of the retina and can lead to significant eye complications later in life. For this reason, in the last few years, antivascular endothelial growth factor agents are being used as monotherapy or as coadjuvant with laser, especially in retinopathy located in zone I. More recently, the administration of oral propranolol has been used as prevention and/or treatment of prethreshold retinopathy with encouraging results. This review provides an overview of the current evidence on newer treatment strategies for ROP. KEY POINTS: · Laser is the standard treatment in threshold retinopathy of prematurity (ROP).. · Prethreshold stages of the ROP have no treatment.. · Propranolol may prevent the progression of ROP..

Infantile Hemangioma: An Updated Review.

Infantile hemangiomas are the most common vascular tumors of infancy, affecting up to 12% of infants by the first year of life. To familiarize physicians with the natural history, clinical manifestations, diagnosis, and management of infantile hemangiomas. A Pubmed search was conducted in November 2019 in Clinical Queries using the key term "infantile hemangioma". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 20 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article. The majority of infantile hemangiomas are not present at birth. They often appear in the first few weeks of life as areas of pallor, followed by telangiectatic or faint red patches. Then, they grow rapidly in the first 3 to 6 months of life. Superficial lesions are bright red, protuberant, bosselated, or with a smooth surface, and sharply demarcated. Deep lesions are bluish and dome-shaped. Infantile hemangiomas continue to grow until 9 to 12 months of age, at which time the growth rate slows down to parallel the growth of the child. Involution typically begins by the time the child is a year old. Approximately 50% of infantile hemangiomas will show complete involution by the time a child reaches age 5; 70% will have disappeared by age 7; and 95% will have regressed by 10 to 12 years of age. The majority of infantile hemangiomas require no treatment. Treatment options include oral propranolol, topical timolol, and oral corticosteroids. Indications for active intervention include hemorrhage unresponsive to treatment, impending ulceration in areas where serious complications might ensue, interference with vital structures, life- or function-threatening complications, and significant disfigurement. Treatment should be individualized, depending upon the size, rate of growth, morphology, number, and location of the lesion (s), existing or potential complications, benefits and adverse events associated with the treatment, age of the patient, level of parental concern, and the physician's comfort level with the various treatment options. Currently, oral propranolol is the treatment of choice for high-risk and complicated infantile hemangiomas. Topical timolol may be considered for superficial infantile hemangiomas that need to be treated and for complicated infantile hemangiomas in patients at risk for severe adverse events from oral administration of propranolol.

Oral propranolol administration is effective for infantile hemangioma in late infancy: A retrospective cohort study.

The highest efficacy of oral propranolol is for infantile hemangioma (IH) in the proliferative phase. Evaluation of the effectiveness of oral propranolol is less established when it is administered in late infancy following the proliferative phase. We aimed to assess the clinical outcomes of pediatric patients managed by oral propranolol beyond the proliferative phase of IH. A retrospective cohort study in a tertiary health care referral center was conducted to track all patients with IH receiving systemic propranolol following the proliferative phase. Twenty-eight eligible patients were managed by 2 to 3 mg/kg per day of oral propranolol for IH beyond the proliferative phase, defined at 9 months of age. The mean age at the initiation of propranolol was estimated at 11.25 (SD 2.24) months. All eligible patients experienced some degree of clinical resolution, with the average improvement rate being estimated at 77.1% (SD 16.1). Comparable results were achieved among patients who were placed on propranolol at an age older than 12 months and those managed between the age of 9 and 12 months. No serious adverse events were observed during the follow-up duration. In conclusion, oral propranolol is a safe and effective treatment for patients with IH initiating this agent beyond the proliferative phase.

Assessment of Oral Propranolol Administration for Infantile Hemangioma in Oral and Maxillofacial Region Aided by Ultrasonography

Propranolol has become the first-line therapy for the treatment of complicated infantile hemangioma. However, there are still many queries regarding the hemangioma volume in relation to drug's dose and duration. The aim of this study was to evaluate the therapeutic effect of oral propranolol for treating infantile hemangiomas in the oral and maxillofacial region aided by gray scale ultrasonography (GSU). Twelve patients with infantile hemangioma, age ranged between 2 and 11 months, have been treated with oral propranolol for 6 months' period. They received a dose of 1 mg/kg per body weight per day, increased after 1 week to 2 mg/ kg per body weight per day maintenance for 24 weeks. The changes in tumor sizes were evaluated by ultrasonography (GSU) using 4-points scale system: excellent, good, fair, poor) RESULTS:: All infants less than 6 months of age showed more hemangiomas regression in size in comparison with of those aged >6 months (P value 0.042) as a rapid response. After the 24 week; 5 patients had excellent results, 4 patients had good results, 2 patients had fair results, and only 1 patient had poor results. None of the treated infants showed rebound phenomena after cessation of treatment. Oral propranolol at dose of 2 mg/kg/day in 2 divided doses for 24 weeks aided by GSU is shown to be a safe and effective treatment of infantile hemangioma during the proliferative phase.

Vectra 3D Imaging for Quantitative Volumetric Analysis of the Efficacy of Propranolol in Infantile Hemangioma

Infantile hemangioma (IH) is a common tumor in infants. After the proliferative phase, hemangiomas regress, but sometimes leave scars. Propranolol is now the recommended first-line oral therapy for IH. To evaluate the effectiveness of oral propranolol administration, we measured quantitative changes in an IH by digital camera and Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). Although digital cameras are very simple, changes in color tones occur with time, lesions are evaluated in two dimensions, and changes in the thickness of the hemangioma are difficult to evaluate. Therefore, we investigated the feasibility of 3D photography to quantify volumes in IH during oral propranolol treatment.

Topical Timolol Vs. Oral Propranolol for the Treatment of Superficial Infantile Hemangiomas.

Objective: Infantile hemangiomas (IHs) are the most common vascular tumors of infancy. Oral propranolol has achieved great success in treating IHs since 2008. To minimize the systemic side events caused by oral administration of propranolol, topical timolol started to be applied in the treatment of IHs, especially for superficial lesions.Methods: We treated 724 children with superficial IHs using oral propranolol or topical timolol, and investigated the efficacy and safety of the two treatment patterns.Results: Both oral propranolol and topical timolol achieved a satisfactory therapeutic outcome, with an effective response rate of 97 and 96.4%, respectively. No significant differences in visual analog scale (VAS) improvement between the two groups were observed. Occurrence rate of systemic adverse events for patients treated with oral propranolol (3.9%) was significantly higher than that for patients treated with topical timolol (0%). Clinical response was not associated with gender, duration of treatment, lesion location, lesion size, gestational age, and progesterone use during pregnancy, but closely associated with age at treatment initiation, which indicated that younger age at treatment initiation predicted for a better regression rate.Conclusions: We recommend that topical timolol instead of oral propranolol could be the first-line therapy for superficial IHs because of its good efficacy and improved safety.

Comparison of botulinum toxin and propranolol for essential and dystonic vocal tremors

OBJECTIVES:Vocal tremors, which cause social difficulties for patients, may be classified as resting or action tremors. Of the vocal action tremors, essential and dystonic tremors are the most common. Botulinum toxin and oral medications have been used to treat vocal tremors, but no comparative clinical trials have been performed. The aim of this study was to compare the effects of botulinum toxin injection and the oral administration of propranolol in the treatment of essential and dystonic vocal tremors.METHODS:This clinical trial recruited 15 patients, divided into essential and dystonic vocal tremor groups. Patients in both groups received successive treatment with botulinum toxin and propranolol. The treatments were administered at different times; the order of treatment was randomly selected. Patients were assessed with flexible nasofibrolaryngoscopy and with perceptual and acoustic voice evaluations. A statistical significance level of 0.05 (5%) was used.RESULTS:Botulinum toxin produced statistically significant improvements in perceptual measures of vocal instability in patients with dystonic vocal tremors compared with baseline values and treatment with propranolol. The acoustic measure of variability in the fundamental frequency was significantly lower in patients with dystonic vocal tremors after treatment with botulinum toxin.CONCLUSION:Essential and dystonic vocal tremors responded differently to treatment. Dystonic vocal tremors responded significantly to treatment with botulinum toxin but not oral propranolol. Essential vocal tremors did not respond significantly to either treatment, perhaps due to the small number of patients, which is a limitation of this research.

Oral Propranolol Administration in Treatment of Hemangiomas: An Update

Oral Propranolol Administration in Treatment of Hemangiomas: An Update

Skeletal muscle proteolysis is associated with sympathetic activation and TNF-α-ubiquitin-proteasome pathway in liver cirrhotic rats.

This study examined the effects of adrenergic blockade on muscle wasting and expression of the ubiquitin-proteasome system, tumor necrosis factor-α (TNF-α) and its signaling pathways in skeletal muscles of cirrhotic rats. Cirrhosis was induced by bile duct ligation in adult male Sprague-Dawley rats for 5 weeks. Oral administration of propranolol (75 mg/kg per day) and intraperitoneal administration of TNF-α receptor antagonist (100 µg/kg per day) were delivered for the last 7 and 14 days experimental periods, respectively. Bile duct ligation caused a reduction of myosin heavy chain protein and muscle wasting. The release of free tyrosine and 3-methylhistidine, MAFbx and MuRF-1 ubiquitin ligase expression, myosin heavy chain protein ubiquitination, and 20S proteasome activity were higher in skeletal muscles of cirrhotic rats than in sham controls. In addition, circulating norepinephrine, protein levels of muscle TNF-α, TNF-α receptor-1, and TNF receptor-associated factor-2, phosphorylation of IKK-α/β, IκB-α, and p65, and NF-κB activity were also increased. Administration of propranolol and TNF-α receptor antagonist led to reduction of post-receptor actions of TNF-α and ubiquitin-proteasome activity in cirrhotic rats. Our findings suggest a potential role of the sympathetic system, in association with pro-inflammatory responses, in the pathogenesis of muscle wasting in liver cirrhosis.

Influence of CYP2D6 and β2-adrenergic receptor gene polymorphisms on the hemodynamic response to propranolol in Chinese Han patients with cirrhosis.

Propranolol is widely used to prevent gastroesophageal variceal bleeding; however, some patients could not benefit from propranolol. This study is to evaluate the relationship between CYP2D6 and β2-adrenergic receptor (β2-AR) gene polymorphisms and the hemodynamic response to propranolol in Chinese Han patients. The clinical data of patients with gastroesophageal varices undergoing hepatic venous pressure gradient (HVPG) measurement before and 7 days after oral propranolol administration in our department were collected. Four single nucleotide polymorphisms of CYP2D6 and β2-AR genes were detected. The relationship was identified by logistic regression model. Thirty patients were involved in the analysis. Sixty milligram propranolol twice each day was well tolerated by all the patients. The initial and secondary average of HVPG was 17.4 ± 5.8 mmHg vs. 13.2 ± 4.8 mmHg, respectively (t = 5.726, P < 0.001). Twenty patients responded to propranolol. The mean reduction value of HVPG was 6.6 ± 3.6 mmHg (range from 3 to 19). Genotype analysis showed: 20 homozygotes for C/C188 and 10 for heterozygous C/T188, 8 homozygotes for G/G4268 and 22 heterozygotes for G/C4268, 14 homozygotes for Gly16 and 10 heterozygotes, and 6 homozygotes for Arg16, 27 homozygotes for Gln27 and 3 heterozygotes. The multivariate logistic regression analysis indicated that CYP2D6 (188C>T) genotype was an independent predicting factor for HVPG response to propranolol (P = 0.033). CYP2D6 (188C>T) gene polymorphisms influence the hemodynamic response to propranolol in this population of Chinese Han patients with gastroesophageal varices. However, HVPG response cannot be completely predicted from CYP2D6 and β2-AR gene polymorphisms.

Use of Three-Compartment Physiologically Based Pharmacokinetic Modeling to Predict Hepatic Blood Levels of Fluvoxamine Relevant for Drug-Drug Interactions

Using a three-compartment physiologically based pharmacokinetic (PBPK) model and a tube model for hepatic extraction kinetics, equations for calculating blood drug levels (Cb s) and hepatic blood drug levels (Chb s, proportional to actual hepatic drug levels), were derived mathematically. Assuming the actual values for total body clearance (CLtot ), oral bioavailability (F), and steady-state distribution volume (Vdss ), Cb s, and Chb s after intravenous and oral administration of fluvoxamine (strong perpetrator in drug-drug interactions, DDIs), propranolol, imipramine, and tacrine were simulated. Values for Cb s corresponded to the actual values for all tested drugs, and mean Chb and maximal Chb -to-maximal Cb ratio predicted for oral fluvoxamine administration (50 mg twice-a-day administration) were nearly 100 nM and 2.3, respectively, which would be useful for the predictions of the DDIs caused by fluvoxamine. Fluvoxamine and tacrine are known to exhibit relatively large F values despite having CLtot similar to or larger than hepatic blood flow, which may be because of the high liver uptake (almost 0.6) upon intravenous administration. The present method is thus considered to be more predictive of the Chb for perpetrators of DDIs than other methods.

A comparison of bolus injection of landiolol versus oral administration of propranolol before cardiac computed tomography

Heart rate (HR) reduction is essential to achieve good image quality for cardiac computed tomography (CCT). We evaluated the efficacy of a bolus injection of landiolol, an ultra-short acting β-blocker, without the administration of oral β-blocker to reduce HR prior to CCT. We enrolled 678 consecutive patients who underwent CCT from December 2011 to March 2012 and divided them into three groups, which were a propranolol group (n = 277), a low-dose landiolol group (n = 188), and a high-dose landiolol group (n = 213). Patients in the propranolol group received oral propranolol (10–20 mg) prior to CCT. Patients in the low-dose and high-dose landiolol groups were administered a bolus injection of landiolol (0.125 mg/kg), while the high-dose group received an additional 3.75 mg of landiolol if the baseline HR was ≥75/min. Although the average HR was significantly lower in the propranolol group (61.6 ± 8.0/min) than in the low-dose landiolol group (64.1 ± 7.4/min, P < 0.001), there was no significant difference in the image quality (P = 0.91). Among patients with baseline HR ≥75/min, the average HR tended to be lower in the high-dose landiolol group (67.2 ± 6.9/min) compared with the low-dose landiolol group (69.0 ± 6.9/min, P = 0.10), and there was a corresponding difference in image quality between these two groups (P = 0.02). In conclusion, Although the decrease of HR was significantly larger in the propranolol group than in the landiolol groups, the image quality was similar. Among the patients who received landiolol, a higher dose was associated with a lower HR and better image quality. Further investigation to assess higher-dose bolus injection of landiolol or bolus injection following oral administration of a β-blocker would be needed.