Review Question - QID 214649

A 44-year-old woman presents to the emergency department acutely obtunded. She has a history of alcohol abuse, withdrawal seizures, multiple suicide attempts, depression, and borderline personality disorder. She recently started taking acetaminophen for back pain. Her temperature is 97.5°F (36.4°C), blood pressure is 104/62 mmHg, pulse is 115/min, respirations are 25/min, and oxygen saturation is 99% on room air. Physical exam reveals a young woman covered in vomit who is irritable and not answering questions. Laboratory studies are ordered as seen below.

Serum:
Na+: 140 mEq/L
Cl-: 101 mEq/L
K+: 4.2 mEq/L
HCO3-: 24 mEq/L
BUN: 30 mg/dL
Glucose: 114 mg/dL
Creatinine: 1.4 mg/dL
Ca2+: 10.0 mg/dL
AST: 220 U/L
ALT: 110 U/L

Venous blood gas:
pH: 7.50
PCO2: 11 mmHg

Urine toxicology:
Cocaine: Positive
Benzodiazepines: Positive
Amphetamines: Positive

She is complaining of numbness around her mouth and muscle spasms, in particular, when her blood pressure is being taken. Which of the following is the most likely etiology of these most recent symptoms?