Droxidopa (L-DOPS) hydrochloride is a potent, orally active precursor to norepinephrine that elevates standing blood pressure, mitigates orthostatic hypotension symptoms, and enhances standing capability. It holds promise for research in neurogenic orthostatic hypotension (nOH) and alternative attention deficit hyperactivity disorder (ADHD) treatments [1] [2] [3] [4].

Administering droxidopa hydrochloride (200 mg/kg; i.p.) modifies the activity of dopamine neurons and the prefrontal cortex, thereby enhancing attention-deficit/hyperactivity disorder (ADHD)-like behaviors in rats [2]. At dosages of 10 and 20 mg/kg (i.p.), it markedly increases paw withdrawal latency and mitigates mechanical hypersensitivity to thermal stimuli in 6-OHDA-lesioned rats five weeks post-surgery [3]. In an animal model using male Sprague-Dawley rats weighing 250-380g [2], a dosage of 200 mg/kg was administered, with a preceding benserazide injection (10 mg/kg, i.p.) 20 or 30 minutes before the L-DOPS infusion. This resulted in a significant reduction in the hyperactivity of BZ-pretreated SHR/NCrl rats at 30 minutes (P < 0.01) and 40 minutes (P < 0.05) post-injection, improved inattention-like behaviors, and lessened impulsive-like behaviors in both SHR/NCrl and Wistar rats.