Effect of Roux-En-Y Gastric Bypass In The Pharmacokinetics of (R)-Carvedilol and (S)-Carvedilol

Roux-en-Y gastric bypass (RYGB) is one of the most common surgical treatments for obesity due to the effective long-term weight loss and remission of associated comorbidities. Carvedilol, a third-generation β-blocker, is prescribed to treat cardiovascular diseases. This drug is a weak base with low and pH-dependent solubility and dissolution, and high permeability. As the changes in the gastrointestinal tract anatomy and physiology after RYGB can potentially affect drug pharmacokinetics (PK), this study aimed to assess the effect of RYGB on the PK of carvedilol enantiomers. Non-obese [n = 15, body mass index (BMI) < 25 kg/m² ], obese (n = 19, BMI ≥ 30) and post-RYGB subjects submitted to surgery for at least 6 months (n = 19) were investigated. All subjects were administered with a single oral dose of 25 mg racemic-carvedilol, and blood was sampled for up to 24 hours. Plasma concentrations of (R)- and (S)-carvedilol were determined by LC-MS/MS. The maximum plasma concentration (C_max ) and the area under the plasma concentration-time curve (AUC) of (R)-carvedilol were 2 to 3-fold higher than (S)-carvedilol in all groups. Obese subjects have shown reduced C_max of (R)- and (S)-carvedilol without changing the AUC. Post-RYGB subjects presented a 3.5-fold reduction in the C_max of the active (S)-carvedilol and a 1.9 reduction in the AUC_∞ compared to non-obese subjects. The time to reach C_max (t_max ) of (S)-carvedilol increased 2.5-fold in post-RYGB subjects compared to obese or non-obese. Although the beta-blockade response was not assessed, the reduced exposure to carvedilol in subjects post-RYGB may be clinically relevant and require dose adjustment. This article is protected by copyright. All rights reserved.

Recycled Household Ash in Rice Paddies of Bangladesh for Sustainable Production of Rice Without Altering Grain Arsenic and Cadmium

In Bangladesh most agronomic biomass (straw, husk, dried dung) is burnt for domestic cooking use. Consequently, the soil is continuously stripped of mineral nutrients and carbon (C) substrate. Here we investigate if recycling of household ash (ash) as fertilizer can sustainably improve soil fertility as well as minimise accumulation of toxic elements (As, Cd) in rice grain. Large scale field trials across two geographic regions (Barind, Madhupur) and two seasons (wet, dry) and with application of 3 fertiliser treatments (NPKS, ash, NPKS + ash) were conducted. At the end of each season, the impact of region*season*treatment on soil microbial comunities, rice yield, and grain quality (As, Cd, nutrient elements) was assessed. When compared to conventional field application rates of NPKS (control), application of ash boosted rice yield by circa. 20% in both regions during wet and dry season, with no effect on rice grain carcinogenic inorganic arsenic (iAs), dimethylarsonic acid (DMA) or cadmium (Cd), but with potential to increase zinc (Zn). For soil microbial communities, a significant region and season effect as well as correlation with elements in rice grain was observed, amongst these Cd, Zn, iAs and DMA. This study illustrates that application of ash can reduce the requirement for expensive chemical fertiliser, whilst at the same time increasing rice yield and maintaining grain quality, making farming in Bangladesh more sustainable and productive. The study also implies that the combined impact of region, season, and soil microbes determines accumulation of elements in rice grain.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12403-023-00539-y.