Doxacurium—No mutagenicity was detected in the Ames Salmonella assay, mouse lymphoma assay, and human lymphocyte assay . However, statistically significant increases in the incidence of structural abnormalities, relative to vehicle controls, occurred in the in vivo rat bone marrow cytogenic assay in male rats receiving 0.1 mg per kg of body weight (mg/kg) (0.625 mg per square meter of body surface area [mg/m 2]) when the animals were sacrificed 6 hours, but not 24 or 48 hours, after administration. Structural abnormalities also occurred in female rats administered 0.2 mg/kg (1.25 mg/m 2) when the animals were sacrificed 24 hours, but not 6 or 48 hours, after administration. Abnormalities did not occur in male or female rats receiving 0.3 mg/kg (1.875 mg/m 2) at any time after administration. Because of the lack of a dose-dependent effect, the likelihood that the abnormalities found in this study were treatment-related or are clinically significant is low .. Tubocurarine (also known as d-tubocurarine or DTC) is a toxic alkaloid historically known for its use as an arrow poison. In the mid-1900s, it was used in conjunction with an anesthetic to provide skeletal muscle relaxation during surgery or mechanical ventilation..