Unintentional fatal toxicity due to nicotine chewing gum: A case report.

Rationale: Since tobacco contains numerous harmful substances, besides nicotine, which is addictive, smoking cessation products and tobacco alternatives, such as electronic (e-) cigarettes, nicotine chewing gums, and patches, are being widely used. Nicotine gums are consumed orally. The nicotine from the gum is absorbed at a slower rate than that from e-cigarettes, and the former remains in the bloodstream for a longer period. In addition, the maximum number of daily doses is high, and it can be purchased without a doctor's prescription in many countries.

Patient Concerns: A 29-year-old male patient consumed 5 2-mg nicotine gums at a time, twice a day, for 4 days (total amount: 70 mg). However, he visited the emergency unit with the chief complaint of involuntary limb movements after consuming an additional 15 gums 3 hour before the visit. At admission, his consciousness was clear, although 2 hour later, he experienced sudden loss of consciousness with worsening hypoxia and respiratory acidosis.

Diagnosis: The patient's vital signs were stable at the time of admission, and blood test results showed no specific findings other than a white blood cell count of 14,800/µL, lactate level of 6.4 mmol/L, and prolactin level of 119.02 ng/mL. In addition, chest radiography and head computed tomography scans showed no acute phase abnormalities. Two hours later, he experienced loss of consciousness and respiratory failure, and the results of blood tests performed at this time showed that his blood cotinine level was 3491 ng/mL.

Interventions: Supportive treatment, including endotracheal intubation followed by mechanical ventilation, was provided.

Outcome: The patient's vital signs stabilized 3 days after treatment, and his consciousness and respiratory status had improved; therefore, mechanical ventilation was stopped. His condition was stable for the next 2 days, and he was discharged on the fifth day.

Lessons: Acute respiratory exacerbation due to nicotine poisoning (from levels exceeding the lethal dose of 30-60 mg) was observed, although the gums were consumed over several days. Patients with nicotine poisoning may show acute respiratory failure and should be monitored carefully. Further studies are required to determine the toxic effects of nicotine replacement therapies.