Urethane (Ethylurethane) was an antineoplastic agent .Now is used for other medicinal purposes.

urethane has a spectrum of action on ion channels, which is distinct from other anesthetics. It significantly potentiates the current responses of both GABAA and glycine receptors in a reversible and concentration-dependent manner. Conversely, urethane (10–300 mM) inhibits the responses of NMDA and AMPA receptors. Also, urethane potentiates the function of an nACh receptor and neuronal nicotinic acetylcholine, γ-aminobutyric acid A, and glycine receptors[3].

Urethane, a carcinogenic substance, is favored for acute in vivo electrophysiological experiments because it induces long-lasting steady level of anesthesia with muscle relaxation and minimally affects the autonomic and cardiovascular systems[2]. Urethane affects both inhibitory and excitatory systems but the magnitude of the alterations is less than that produced by other more selective anesthetics[3]. But also, Urethane anesthesia is usually restricted to terminal (acute) experiments due to its potential long-term toxicity[1].