Methoxamine is an α₁-adrenergic receptor agonist, similar in structure to phenylephrine

Phenylephrine

Phenylephrine is a selective α1-adrenergic receptor agonist used primarily as a decongestant, as an agent to dilate the pupil, and to increase blood pressure...

 and 2,5-DMA. It was Developed by Burroughs-Wellcome in the 1940s. The drug induces vasoconstriction of skin and splanchnic

Splanchnic

Splanchnic, from a Greek word spēn, meaning organ, usually used to describe visceral organs.More specifically, it can also refer to:* An adjective describing the intestines* Splanchnic nerves* Splanchnic mesoderm...

 blood vessels, thereby increasing peripheral vascular resistance and raising mean arterial blood pressure. Because of its hypertensive effects, it may evoke a compensatory reflex bradycardia

Bradycardia

Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...

 via the baroreceptors.