American Nurses Credentialing Center (ANCC) Practice Exam

Cocaine is known to cause both epistaxis (nosebleeds) and tachycardia (increased heart rate). When used recreationally, cocaine acts as a powerful stimulant that can lead to vasoconstriction in the nasal passages, resulting in the rupture of blood vessels and subsequent nosebleeds. Additionally, the stimulating effects of cocaine on the central nervous system can lead to an elevated heart rate, or tachycardia, as the body responds to the increased sympathetic nervous system activity. This substance's effects are well-documented, making it a plausible explanation for the patient's symptoms.

In contrast, oxycodone and morphine are opioids that typically do not lead to tachycardia; instead, they may cause sedation or bradycardia (decreased heart rate). Benzodiazepines like alprazolam are primarily depressants that can also cause sedation without typically inducing epistaxis or increased heart rate. Thus, cocaine stands out as the substance most likely responsible for the symptoms presented in the scenario.