Barbosa J, Faria J, Garcez F, et al. Repeated Administration of Clinically Relevant Doses of the Prescription Opioids Tramadol and Tapentadol Causes Lung, Cardiac, and Brain Toxicity in Wistar Rats. Pharmaceuticals (Basel). 2021;14(2):97. Published 2021 Jan 27. doi:10.3390/ph14020097