Clinical phenotypes and early treatment escalation in pediatric acute drug-induced dystonia: A tertiary emergency department cohort study.

UNLABELLED: To characterize the clinical phenotypes and pharmacological profile of pediatric acute drug-induced dystonia (DID) and to evaluate whether initial treatment escalation in complex presentations reduces the need for repeat antidystonic dosing. In this retrospective cohort study, 132 children diagnosed with acute DID in a tertiary pediatric emergency department were analyzed. Causative agents were categorized by pharmacological mechanism, identifying potent dopamine D2 receptor antagonists (metoclopramide and antipsychotics). Presentations were classified as pure dystonia or complex phenotypes (dystonia with additional systemic/neurologic features). Firth's penalized logistic regression and propensity score matching were used to assess predictors of repeat antidystonic treatment (≥ 2 doses). The median age was 13.7 years (IQR 10.1-16.4). Potent D2 antagonists accounted for 73.5% of cases. Pure dystonia was observed in 78.0%, and 22.0% had complex phenotypes. Initial combination therapy was more frequent in complex cases (10.3% vs. 0%, p = 0.010). Repeat dosing was required in 8.3%. No independent predictors were identified; however, exposure to potent D2 antagonists showed a non-significant association with repeat treatment (OR 4.01; 95% CI 0.47-33.95), an estimate of the study was underpowered to confirm. Despite greater initial severity, complex phenotypes did not have higher repeat dosing rates.

CONCLUSION: Pediatric DID in this cohort predominantly affected adolescents and was driven by potent D2 antagonist exposure. Complex presentations more often received initial combination therapy yet did not show higher repeat-dosing rates; whether this reflects effective early escalation or simply that complex phenotypes are not inherently more refractory cannot be determined from this design and warrants prospective study.

WHAT IS KNOWN: • Acute drug-induced dystonia is a frequent pediatric emergency adverse event, most often triggered by antiemetics and antipsychotics. • Management relies on anticholinergic monotherapy; prior studies mainly describe epidemiology rather than predictors of short-term treatment course.

WHAT IS NEW: • The affected population was predominantly adolescent (median 13.7 years), and potent D2-blocking agents showed a non-significant association with higher repeat dosing (OR 4.01) that the study was underpowered to confirm. • Complex phenotypes were more likely to receive initial combination therapy (p = 0.010), yet repeat dosing rates were not higher than in pure dystonia.