(939) Breaking Boundaries: Atomoxetine Unleashed as the Pressor-Sparing Maverick

Introduction: Atomoxetine is a selective norepinephrine transporter blocker and is a FDA-approved ADHD medication with an off-label use for neurogenic orthostatic hypotension (OH). Side effects include tachycardia and hypertension. Discussed below is the novel use of atomoxetine as a pressor-sparing agent in a patient who failed conventional pressor-weaning methods.

Description: A 74-year-old male was admitted for gastric outlet obstruction with a complex hospital course leading to a decompensated state, including renal failure requiring hemodialysis, respiratory failure requiring tracheostomy, several complex abdominal surgeries, a large surgical site hematoma and persistent hypotension (52 days) requiring a prolonged low-dose NE infusion. Despite attempting to wean the patient from NE using midodrine, steroids, and volume resuscitation, the patient remained NE dependent. His prolonged decompensated state possibly led to central autonomic dysfunction (i.e., multiple system atrophy) and elevated NE levels greater than 220 pg/ml (i.e., prolonged NE infusion), and atomoxetine was presented as a potential pressor-sparing treatment option. Atomoxetine 10 mg twice daily was initiated. The patient’s hypotension improved after the first dose, and he was successfully liberated from NE.

Discussion: Midodrine is used in the ICU as a pressor-sparing agent due to alpha-1 agonist properties. Alternatively, atomoxetine enhances peripheral vasoconstriction and central vasodilation via alpha-2 receptors. Patients with central autonomic failure and preserved peripheral sympathetic neurons have responded well to atomoxetine. Atomoxetine was trialed after failing standard-of-care treatment options. Atomoxetine’s peripheral vasoconstriction properties have shown to have a greater pressor effect response in patients with higher NE levels and those with OH and autonomic dysfunction.
Atomoxetine is safe, well tolerated, and effective in patients with OH and normal or elevated NE levels. To our knowledge, this is the first report of atomoxetine as a pressor-sparing agent. Further studies will be needed to evaluate the safety and efficacy of atomoxetine as a pressor-sparing agent for patients with mild autonomic dysfunction without OH.