A 5-year-old boy is brought to the emergency department due to accidental drug ingestion. His mother states the patient was playing by himself earlier today and 2 hours later she found him unresponsive in the bathroom. There was an empty bottle of hydrocodone-acetaminophen next to him, but she does not know how many pills were in it. The emergency medical team found the patient stuporous and with bradypnea. His mental status and respirations promptly improved after 1 dose of intravenous naloxone was administered, and he was transported to the hospital. On arrival, the patient is sleepy but arouses easily to voice and follows simple instructions. Vital signs, including respirations, are normal. One hour later, he has worsening lethargy, bradypnea, and miosis. Which of the following most likely accounts for this patient's current clinical deterioration?

Question

A 5-year-old boy is brought to the emergency department due to accidental drug ingestion.  His mother states the patient was playing by himself earlier today and 2 hours later she found him unresponsive in the bathroom.  There was an empty bottle of hydrocodone-acetaminophen next to him, but she does not know how many pills were in it.  The emergency medical team found the patient stuporous and with bradypnea.  His mental status and respirations promptly improved after 1 dose of intravenous naloxone was administered, and he was transported to the hospital.  On arrival, the patient is sleepy but arouses easily to voice and follows simple instructions.  Vital signs, including respirations, are normal.  One hour later, he has worsening lethargy, bradypnea, and miosis.  Which of the following most likely accounts for this patient's current clinical deterioration?

Quizplus · Accepted Answer

11ec160b_3c42_4572_9249_e7198872ec15_MD0001_00 This young boy, who was found with an empty bottle of hydrocodone-acetaminophen, has evidence of an acute opioid overdose. Opioids (eg, hydrocodone, methadone) exert their analgesic effect via multiple opioid receptors (eg, delta, kappa, mu) in the central and peripheral nervous systems. Typical features of overdose include decreased level of consciousness, reduced respiratory rate, decreased bowel sounds, and miosis. Naloxone, a short-acting opioid antagonist, is the primary treatment for acute opioid toxicity and rapidly reverses respiratory depression. However, it has a short half-life (<1 hr), and most opioids take significantly longer to metabolize (eg, half-life of hydrocodone is 4-8 hrs). Therefore, patients may develop recurrent symptoms of opioid toxicity after naloxone is metabolized, and frequent redosing may be necessary. (Choice A) Acetaminophen poisoning typically causes nausea, vomiting, and malaise in the first 24 hours after ingestion. Liver failure occurs later, and patients typically have jaundice, tachypnea, and confusion (ie, hepatic encephalopathy) that may progress to coma. Bradypnea and miosis are more consistent with opioid toxicity. (Choice B) Although benzodiazepines cause sedation and respiratory depression, miosis does not occur. In addition, benzodiazepine toxicity is treated with flumazenil, and symptoms would not be expected to improve with naloxone. (Choice C) Naloxone has excellent CNS penetrance, and this patient's temporary improvement in respiratory rate and somnolence suggests adequate CNS effect. Opioid medications that do not cross the CNS (eg, loperamide) have effects mainly on the gastrointestinal tract and are used to treat diarrhea. (Choice D) Naloxone is a pure opioid antagonist; it does not have partial agonist activity. Buprenorphine is a partial opioid agonist used to prevent opioid withdrawal while reducing the risk of opioid intoxication (eg, euphoria, respiratory depression). Educational objective: Naloxone is a short-acting opioid antagonist used for the treatment of opioid overdose (eg, respiratory depression, decreased level of consciousness, miosis, decreased bowel sounds). Naloxone frequently requires redosing to prevent recurrent overdose symptoms due to its short half-life (<1 hr).

A 5-Year-Old Boy Is Brought to the Emergency Department Due