Year: 2026
Type: article
Study design: Case Report
Abstract: Over-the-counter (OTC) melatonin is widely perceived as benign, yet its unregulated, high-dose formulations create an accessible means of self-harm for adolescents, and reports of intentional overdose have risen alongside a well-documented surge in pediatric exposures. We report a 16-year-old female who intentionally ingested 450 mg of melatonin (90 × 5 mg tablets), a 90-fold supratherapeutic dose, and synthesize this case against the published literature on melatonin overdose, suicidality, and toxicokinetics. She presented 2.5 h post-ingestion with marked somnolence (Glasgow Coma Scale 13/15) and heart rate of 62 beats/min. Venous blood gas showed a mild, respiratory-compensated metabolic acidosis (pH 7.34, HCO3 15.6 mmol/L), with mild hyponatremia and stress leukocytosis. Hepatic, renal, and coagulation studies and a 12-lead electrocardiogram were normal, and a comprehensive toxicology screen was negative, consistent with an isolated exposure (Poison Severity Score Grade 1, Minor). She was medically cleared within 14.5 h of ingestion but, given persistent suicidal ideation on psychiatric evaluation, was transferred to inpatient psychiatric care at 20.5 h post-ingestion. This case, together with a review of published case reports, cohort data, and toxicokinetic evidence, indicates that massive isolated melatonin ingestion typically produces self-limited sedation, consistent with saturable hepatic CYP1A2-mediated clearance, alongside mild, transient metabolic derangement without organ injury. Population-level and case-level evidence converge, however, on a critical message for clinicians: low physiological toxicity does not indicate low psychiatric risk, and every adolescent presenting after intentional OTC chronobiotic ingestion warrants formal psychiatric evaluation regardless of how benign the medical course appears.
Source: Frontiers in Toxicology
Language: English
Subfield: Emergency Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,077
OpenAlex ID: W7222040932