A 24-year-old male patient is unconscious and suspected of heroin overdose. The altered mental status is due to which toxic-metabolic cause?

In the context of an unconscious patient suspected of a heroin overdose, the altered mental status is primarily due to poisoning. Heroin is an opioid that depresses the central nervous system, leading to sedation and loss of consciousness. Toxic-metabolic causes of altered mental status typically involve substances that interfere with normal brain function; in this case, heroin acts as a potent analgesic and sedative.

While infection, shock, and dysrhythmia can also lead to altered mental status, they are not the primary concern in the case of a heroin overdose. Infections might create systemic effects that could influence mental status but would not specifically point to the acute issue presented here. Shock and dysrhythmia can lead to altered mental status as well; however, they are more generalized conditions that do not specifically relate to the immediate effects of a specific toxic agent like heroin.

Recognizing that the patient is likely experiencing the life-threatening effects of opioid toxicity reinforces the understanding that poisoning—in this case, from heroin—is the correct interpretation of the scenario and the most relevant factor contributing to the patient's diminished consciousness.