EMTs assess a man under the influence of an unknown substance. Which drug would MOST likely cause agitation, high BP, and increased pulse?

The drug that would most likely cause agitation, high blood pressure, and an increased pulse is cocaine. This stimulant is known for its effects on the central nervous system, leading to heightened alertness, energy, and physiological changes such as increased heart rate and elevated blood pressure. Users often exhibit symptoms of agitation and restlessness, which align with the observed condition of the man in this scenario.

Cocaine achieves these effects by increasing the levels of dopamine in the brain, which can lead to a sense of euphoria as well as overstimulation of the cardiovascular system. This is in stark contrast to the other substances listed. Heroin typically causes sedation and respiratory depression, alcohol primarily acts as a depressant resulting in decreased vital signs, and Valium, a benzodiazepine, also results in sedation and decreased anxiety rather than increased heart rate or agitation. Hence, cocaine is the most fitting answer given the described symptoms.