Levalbuterol versus albuterol

Unconventional interactions of the TRPV4 ion channel with beta-adrenergic receptor ligands

The transient receptor potential vanilloid 4 (TRPV4) ion channel is present in different tissues including those of the airways. This channel is activated in response to stimuli such as changes in temperature, hypoosmotic conditions, mechanical stress, and chemicals from plants, lipids, and others. TRPV4's overactivity and/or dysfunction has been associated with several diseases, such as skeletal dysplasias, neuromuscular disorders, and lung pathologies such as asthma and cardiogenic lung edema and COVID-19-related respiratory malfunction. TRPV4 antagonists and blockers have been described; nonetheless, the mechanisms involved in achieving inhibition of the channel remain scarce, and the search for safe use of these molecules in humans continues. Here, we show that the widely used bronchodilator salbutamol and other ligands of β-adrenergic receptors inhibit TRPV4's activation. We also demonstrate that inhibition of TRPV4 by salbutamol is achieved through interaction with two residues located in the outer region of the pore and that salbutamol leads to channel closing, consistent with an allosteric mechanism. Our study provides molecular insights into the mechanisms that regulate the activity of this physiopathologically important ion channel.

Effect of Chiral Purity on Adjuvanticity of Archaeol-Based Glycolipids

Archaeosomes composed of sulfated lactosyl archaeol (SLA) glycolipids from stereoisomerically pure archaeol (1) are vaccine adjuvants that can boost immunogenicity and vaccine efficacy in preclinical models. Herein, we report a new synthesis of 2,3-bis((3,7,11,15-tetramethylhexadecyl)oxy) propan-1-ol (3) by treating (±)-3-benzyloxy-1,2-propanediol with a mesylated phytol derivative through a double nucleophilic substitution reaction, followed by reductive debenzylation. Three SLA archaeosomes from archaeols of different chiral purities were prepared, and the effect of stereochemistry on their adjuvanticity toward ovalbumin was investigated. It was found that all SLA archaeosomes induced strong humoral and cell-mediated antigen-specific immune responses following immunization of C57BL/6NCrl mice, with no significant differences, irrespective of the chiral purities. The responses were comparable or better than those obtained using mimetics of approved adjuvants. The performance of SLA archaeosomes during immunization and their lack of dependence on the stereochemistry of archaeol points toward a promising, safe, scalable, and economically viable vaccine adjuvant system.

The effects of R-salbutamol on growth, carcass measures, and health of finishing pigs

A pure form of salbutamol has the potential to deliver positive production benefits to the swine industry. The aim of this experiment was to determine the effects of salbutamol on growth, carcass measures, and health of finishing pigs. The study used 192 pigs (89 ± 1 kg BW) housed in groups of 6 in 32 pens and assigned to 1 of 4 treatments: 1) control (CTL), 0 mg/kg salbutamol; 2) 2R, control diet with 2 mg/kg of the pure R-enantiomer of salbutamol; 3) 4R, control diet with 4 mg/kg of pure R-salbutamol; or 4) 8RS, control diet with 8 mg/kg of a 50:50 mixture of the R- and S-enantiomers. All diets were offered ad libitum for 4 wk. All pigs were weighed and pen feed intakes were recorded weekly. At slaughter, individual HCW and measurements of the 10th-rib loin muscle area (LMA), color, marbling, firmness, and back fat, last lumbar, and midline back fat depths were collected. Data were analyzed using Proc GLM of SAS, with pen as the experimental unit. Overall, 2R and 4R pigs had greater ADG than CTL pigs (P < 0.05) and, at slaughter, were heavier than CTL pigs (P < 0.01). Overall, 8RS pigs had decreased ADFI (P < 0.05), and CTL pigs had poorer G:F (P < 0.001) than the other 3 treatments. All salbutamol-fed pigs had 5 to 6 kg greater HCW (P < 0.001), 2% to 3% increased carcass yield (P < 0.001), 5.6 cm(2) larger LMA (P < 0.01), 3 to 4 mm less 10th-rib back fat (P < 0.01), and 2 mm less lumbar back fat (P < 0.05) than CTL pigs. However, control pigs had greater loin muscle color scores (P < 0.05) and marbling scores (P < 0.001) than all salbutamol-treated pigs. Taken together, these data indicate that as little as 2 mg/kg R-salbutamol has a positive effect on pig growth and carcass composition. However, the effects of salbutamol on meat quality require further research.

Effect of bronchodilator treatment on the incidence of postoperative atrial fibrillation after cardiac surgery

OBJECTIVE

We sought to examine the effects of bronchodilator treatment on the incidence of postoperative atrial fibrillation (POAF) after cardiac surgery.

METHODS

A cross-sectional design using a retrospective chart review was performed in patients who underwent cardiac surgery. Those who had previous atrial fibrillation or preoperative bronchodilator treatment were excluded from the final sample (n = 506). The Statistical Package for the Social Sciences (SPSS, Inc., Chicago, IL) was used for statistical analyses.

RESULTS

The incidence of POAF in this study was 27.9%, and was associated with age (P < .01) and type of cardiac surgery (P < .05), indicating that increasing age, and combined cardiac surgery were more likely to precipitate POAF. Bronchodilator treatment did not increase POAF. However, combined therapy significantly (P < .01) precipitated more POAF (48.7%) than did albuterol (21.4%) or levalbuterol (18.5%).

CONCLUSIONS

Postoperative atrial fibrillation continues to be a common complication after cardiac surgery. Bronchodilator treatment with either albuterol or levalbuterol did not precipitate POAF, unless both agents were given to the same patients postoperatively.

Comparison of Pediatric Levalbuterol and Albuterol Exposures Reported to Texas Poison Centers

Background:

Levalbuterol is R-albuterol, which is the active isomer and accounts for the therapeutic activity of albuterol. The effects of S-albuterol are often the opposite of those of levalbuterol, and the effects of levalbuterol may be diminished in the presence of S-albuterol.

Objective:

To compare exposures among young children to levalbuterol and albuterol that were reported to poison centers.

Methods:

Cases included levalbuterol and albuterol exposures among patients age 0–5 years reported to Texas poison centers during 2000–2009. The distribution of total cases for each medication was determined for selected characteristics. For cases not involving other substances and where a final medical outcome was known, the distribution of each medication was determined for outcome and management site of the exposure and most common clinical effects and treatments. Comparisons were made by calculating the rate ratio (RR) and 95% confidence interval.

Results:

There were a total of 1,012 levalbuterol and 4,338 albuterol exposures. Other substances were involved in 11.8% of levalbuterol and 6.6% of albuterol exposures (RR 1.77, 95% CI 1.42 to 2.20). No effect was reported in 84.0% of levalbuterol and 71.9% of albuterol exposures (RR 1.17, 95% CI 1.03 to 1.32), and 91.7% of levalbuterol and 73.1% of albuterol exposures were managed on site (RR 1.26, 95% CI 1.11 to 1.41). The most common adverse clinical effects were reported more frequently among albuterol exposures. The most frequent treatments of levalbuterol and albuterol exposures were, respectively, dilution 59.5% and 42.0% (RR 1.42, 95% CI 1.22 to 1.64), food 18.9% and 12.8% (RR 1.48, 95% CI 1.12 to 1.94), single-dose activated charcoal 0.3% and 10.1% (RR 0.03, 95% CI 0.00 to 0.15), and cathartic 0.0% and 4.6% (RR 0.00, 95% CI 0.00 to 0.22).

Conclusions:

Among exposures involving children aged 0–5 years that were reported to Texas poison centers, levalbuterol was more likely to include other substances, have less serious outcomes, and be managed on site when compared to albuterol.

Respiratory safety pharmacology: concurrent validation of volume, rate, time, flow and ratio variables in conscious male Sprague-Dawley rats

This study compares basic respiratory variables (rate, tidal and minute volumes) with time-, flow- and ratio-derived parameters obtained using head-out plethysmography in rats following administration of reference drugs (isotonic saline, 2.0 mL/kg, IV; albuterol, 400 μg/kg, inhalation; methacholine, 136 μg/kg, IV; and remifentanil, 14 μg/kg, IV) to identify respiratory variables with superior sensitivity. Paired t-tests by block-period, and analysis of covariance (ANCOVA) with baseline as covariate and a posteriori pair-wise comparisons using Dunnett's test were used. Variations in respiratory parameters observed over time justify the use of a control group in any respiratory safety pharmacology study for inter-groups comparison. Handling-, and slumbering-, induced perturbations were minimal. The system was sensitive and specific to detect changes in respiratory variables related to pharmacologically-induced bronchodilation, bronchoconstriction and central respiratory depression. The standard variables (respiratory rate, tidal and minute volumes) confirmed to be the cornerstone of respiratory safety pharmacology to detect pharmacological changes. Flow-derived parameters appeared as highly valuable complement for interpretation of respiratory response, whereas time- and ratio-derived parameters presented limited added value during interpretation.