A nurse admits a patient who reports taking two extra-strength acetaminophen tablets (500 mg) up to six times daily to treat chronic headaches. Which of the following orders should the nurse anticipate?

Choice A rationale Selective serotonin receptor agonists (SSRAs), like triptans, are used to treat acute migraine headaches by stimulating serotonin receptors, causing vasoconstriction. While the patient has chronic headaches, taking high doses of acetaminophen is associated with hepatotoxicity, not direct SSRA indications. The priority order would address potential liver damage before starting migraine-specific therapy, as SSRAs are not used for chronic, non-migraine headaches. Choice B rationale Docusate sodium, a stool softener, is used to prevent constipation by increasing water incorporation into the stool, making it easier to pass. Although opioids, which can cause constipation, are sometimes used for severe pain, this patient is taking acetaminophen, which does not commonly cause constipation. The primary concern with chronic, high-dose acetaminophen is potential hepatotoxicity, making liver function assessment the priority. Choice C rationale Chronic high-dose acetaminophen ingestion (above the maximum recommended 4,000 mg/day) puts the patient at significant risk for hepatotoxicity due to the accumulation of a toxic metabolite, N-acetyl-p-benzoquinone imine (NAPQI), which depletes hepatic glutathione stores. Alanine transaminase (ALT) and aspartate transaminase (AST) are liver enzymes; elevated levels (normal ALT is about 7 to 55 U/L and AST is about 8 to 48 U/L) are key indicators of hepatocellular damage. Choice D rationale A basic metabolic profile (BMP) assesses electrolytes and kidney function, while a complete blood count (CBC) evaluates formed blood elements. While helpful for a general assessment, BMP and CBC are less specific for the immediate, high-priority concern of acetaminophen-induced liver damage than ALT and AST. Acetaminophen overdose primarily targets the liver, not causing immediate, profound electrolyte or hematological derangements.