Combination Therapy for Neurogenic Orthostatic Hypotension

Rationale and Evidence

The American College of Cardiology, American Heart Association, and Heart Rhythm Society guidelines recommend midodrine and droxidopa as separate therapeutic options for neurogenic orthostatic hypotension, with Class IIa recommendations 1, 2.
Midodrine works as a peripheral selective α1-adrenergic agonist, causing direct arteriolar and venous constriction, while droxidopa functions as a norepinephrine prodrug, increasing systemic norepinephrine levels 1, 2, 3, 4.
The 2023 ACC Expert Consensus on cardiac amyloidosis lists both midodrine and droxidopa as treatment options for orthostatic hypotension, acknowledging their use in complex patients 5.

Patients with refractory neurogenic orthostatic hypotension may benefit from combination therapy with midodrine and droxidopa, with the American College of Cardiology acknowledging the potential benefits of this combination 1, 2.
The American College of Cardiology recommends that patients with heart failure or restrictive cardiac physiology be carefully evaluated before starting combination therapy, as they may tolerate these medications poorly 5.
The American Heart Association suggests that patients with Parkinson's disease using carbidopa may experience decreased effectiveness of droxidopa 1, 2.

The American College of Cardiology recommends monitoring standing blood pressure and symptom improvement within 1-2 weeks of initiating combination therapy, and adjusting the dose as needed to minimize supine hypertension 1, 2.
The American Heart Association suggests that ambulatory blood pressure monitoring be used to assess for supine hypertension, particularly at night 1, 2.

If combination therapy is needed but poorly tolerated, the American College of Cardiology suggests considering adding pyridostigmine instead, which does not cause fluid retention or supine hypertension 4, 5.
The American Heart Association recommends maximizing non-pharmacologic measures, such as compression garments, physical counter-pressure maneuvers, and increased salt/fluid intake, before initiating combination therapy 1, 2, 6, 7.