Persistence of the tricyclic antidepressant drugs amitriptyline and nortriptyline in agriculture soils

Abstract

Abstract-Amitriptyline and nortriptyline are widely used tricyclic antidepressant drugs. They have been detected in wastewater, surface runoff, and effluents from sewage treatment plants. As such, they could potentially reach agriculture land through the application of municipal biosolids or reclaimed water. In the absence of data on their fate in the environment, the persistence and dissipation pathways of radiolabeled amitriptyline were determined in three agriculture soils varying widely in texture and chemical properties (loam soil, clay loam soil, and sandy loam soil). Tritiated amitriptyline was added to laboratory microcosms containing soils, and the metabolism of the extractable 3 H was monitored during incubation at 308C. The total solvent extractable radioactivity decreased in all three soils with times to dissipate 50% of material (DT50) ranging from 34.1 AE 3.2 (loam soil) to 85.3 AE 3.2 d (sandy soil). Nortriptyline (N-desmethyl amitriptyline) and amitriptyline-N-oxide were identified as major transformation products in all three soils by high performance liquid chromatography with photodiode array detector and time-of-flight mass spectrometry (HPLC-TOF-MS/UV). The addition of liquid municipal biosolids to the loam soil had no effect on the dissipation of amitriptyline. The persistence of nortriptyline was evaluated in the loam soil. The DT50 of nortriptyline was 40.5 AE 3.2 d estimated with HPLC-TOF-MS/UV. Approximately 10% of added nortriptyline was converted to hydroxylated products after 50 d of incubation. In summary, amitriptyline persisted in agricultural soils with major dissipation mechanisms, including forming nonextractable residues and producing various transformation products including the psychoactive drug nortriptyline. Environ. Toxicol. Chem. 2013;32:509-516. # 2012 SETAC

Factors affecting the dissipation of pharmaceuticals in freshwater sediments

“…Although, to the best of our knowledge, no literature data are available on the degradation of amitriptyline in sediment, the persistence of the compound has been explored in soil. Our half‐lives are similar to those reported in soils with different textures where DT50s ranging from 34.1 to 85.3 d were observed (Li et al ). In the present study, the dissipation of amitriptyline was suggested to result from the formation of nonextractable residues and the degradation of the parent compound to nortriptyline ( N ‐desmethyl amitriptyline) and amitriptyline‐ N ‐oxide.…”

“…For example, soil texture was found to affect the degradation rates of caffeine, with faster degradation being observed in loam and sandy loam soils compared with a silt loam soil (Topp et al ). Amitriptyline also showed faster dissipation in a loam soil compared with clay and sandy soils (Li et al ). Benotti and Brownawell () reported variations in degradation rates for 19 pharmaceuticals in estuarine and coastal surface water samples and suggested that faster rates of pharmaceutical degradation occurred in waters with a greater abundance of total bacteria or the presence of microbial communities that are better able to transform these compounds.…”

Impact of the wastewater-mixing zone on attenuation of pharmaceuticals in natural waters: Implications for an impact zone inclusive environmental risk assessment

“…These differences highlight the variability in behaviour of this API with the experimental conditions employed. While only a few studies on the persistence of AMI have been documented, these report high persistence in both water (Baena-Nogueras et al, 2017) and agricultural soils (Li et al, 2013), in agreement with the data from this study ( Figure 3G).…”

Photosensitized Degradation of Amitriptyline and Its Active Metabolite Nortriptyline in Aqueous Fulvic Acid Solution

“…Antidepressants are frequently prescribed pharmaceuticals used for humans and animals. Amitriptyline is one of the mostly widely used tricyclic antidepressants for treatment of depression, anxiety, and a variety of chronic pain syndromes (Li et al, 2013; Ivetić et al, 2016). It is mainly metabolized by demethylation, forming nortriptyline (Farnoudian‐Habibi et al, 2016).…”