droxidopa

Droxidopa, also known as L-threo-3,4-dihydroxyphenylserine (DOPS), is a synthetic amino acid precursor of norepinephrine. It is a prodrug that is converted by aromatic L-amino acid decarboxylase to norepinephrine in the peripheral nervous system. By increasing circulating norepinephrine, droxidopa enhances vascular tone and can raise standing blood pressure in patients with neurogenic orthostatic hypotension due to autonomic failure.

Indications: Droxidopa was approved by the U.S. Food and Drug Administration in 2014 for symptomatic neurogenic orthostatic hypotension. It is indicated in adults with NOH due to primary autonomic disorders or diseases such as multiple system atrophy or Parkinson's disease with autonomic failure.

Administration and pharmacokinetics: It is taken orally, typically two to three times daily. The effect depends on peripheral decarboxylase activity, and dosage may be adjusted to balance symptom relief with the risk of hypertension. The drug has a relatively short duration of action, requiring multiple daily doses.

Adverse effects: Common adverse effects include headache, dizziness, nausea, fatigue, and hypertension. Supine hypertension is a notable risk. Other possible effects include tachycardia, syncope, edema, and urinary symptoms.

Interactions and precautions: Caution is advised in patients with cardiovascular disease, cerebrovascular disease, or uncontrolled hypertension. Use with drugs that increase norepinephrine or with other vasopressors may raise blood pressure further. Carbidopa/levodopa may reduce conversion of droxidopa to norepinephrine, potentially decreasing effectiveness.

Regulatory status: Brand name Northera; developed by Chelsea Therapeutics and later marketed by Lundbeck after acquisition. FDA approval in 2014 established its use for neurogenic orthostatic hypotension.