Methyldopa as a novel therapeutic option for paroxysmal sympathetic hyperactivity in pediatric patients: A case report

Paroxysmal sympathetic hyperactivity (PSH) is a clinical syndrome characterized by intermittent episodes of excessive sympathetic and motor activity, including tachycardia, hypertension, hyperthermia, tachypnea, excessive diaphoresis, and abnormal posturing. Clonidine, an α2-adrenergic agonist, is used as a treatment for PSH, demonstrating efficacy across multiple studies. However, market withdrawal and the lack of a generic alternative in Japan have prompted the need for other therapeutic options. Case 1 was 2-year-old boy with trisomy 13 complicated by holoprosencephaly, severe intellectual disability, and mixed quadriplegia. His PSH had been well-controlled with clonidine, which was successfully replaced with methyldopa after discontinuation of the former. Case 2 was a 1-year-old boy diagnosed with early infantile epileptic encephalopathy caused by a KCNQ2 mutation. PSH symptoms and elevated creatine kinase levels were alleviated with gabapentin and methyldopa. We present the first two pediatric cases of PSH successfully managed with methyldopa, another α2-adrenergic agonist, as an alternative to clonidine. Methyldopa may serve as a promising alternative treatment for pediatric patients with PSH, particularly in settings where clonidine is unavailable. Further studies are required to evaluate the efficacy, safety, and long-term outcomes of methyldopa in this population.