If a patient shows signs of maligant hypertension due to cocaine use, which medication would be most appropriate?

The most appropriate medication for a patient showing signs of malignant hypertension due to cocaine use is labetalol. Cocaine can significantly raise blood pressure and lead to hypertensive emergencies, and labetalol is a mixed alpha and beta-adrenergic blocker that effectively lowers blood pressure by causing vasodilation and reducing heart rate. It is particularly useful in treating hypertension that is symptomatic or life-threatening, such as in this case of malignant hypertension.

The mechanism of labetalol helps to manage the severe cardiovascular effects associated with cocaine use, providing both immediate blood pressure control and reducing the risk of further complications. It can be administered intravenously in emergency settings, making it a practical choice for acute management.

While the other medications listed have their indications, they do not address the specific pathology of cocaine-induced malignant hypertension effectively. Atropine is generally used for bradycardia, naloxone is an opioid antagonist and not relevant to cocaine hypertension, and disulfiram is used in alcohol dependence but does not affect acute hypertension.