<prompt> Which of the following is most useful for reversing severe ergot induced vasopamErgotamineMethysergideNitroprussidePhenoxybenzamine  <response>: this agent is mixed dilator and is Highly Effective agent against ergot induced vasospasm. it is also the drug of choice for most of the hypeensive emergencies Ref-Goodman and Gillman 11e p311 