Dental pain as a risk factor for accidental acetaminophen overdose: a case-control study

Patients frequent take acetaminophen to treat dental pain. One previous study found a high rate of overuse of nonprescription analgesics in an emergency dental clinic.

The purpose of this study is to determine if patients with dental pain are more likely to be treated for accidental acetaminophen poisoning than patients with other types of pain.

We conducted a case-control study at 2 urban hospitals. Cases were identified by chart review of patients who required treatment for accidental acetaminophen poisoning. Controls were self-reported acetaminophen users taking therapeutic doses identified during a survey of emergency department patients. For our primary analysis, the reason for taking acetaminophen was categorized as dental pain or not dental pain. Our primary outcome was the odds ratio of accidental overdose to therapeutic users after adjustment for age, sex, alcoholism, and use of combination products using logistic regression.

We identified 73 cases of accidental acetaminophen poisoning and 201 therapeutic users. Fourteen accidental overdose patients and 4 therapeutic users reported using acetaminophen for dental pain. The adjusted odds ratio for accidental overdose due to dental pain compared with other reasons for use was 12.8 (95% confidence interval, 4.2-47.6).

We found that patients with dental pain are at increased risk to accidentally overdose on acetaminophen compared with patients taking acetaminophen for other reasons. Emergency physicians should carefully question patients with dental pain about overuse of analgesics.