Droxidopa

 Q: Droxidopa is potentially an oral form of? (select one)

A) Dopamine

B) Norepinephrine

Answer: B

Droxidopa is chemically a  L-dihydroxyphenylserine. It is also known as DOPS. Relatively less known, it is a synthetic oral amino acid. It is basically a levodopa with an added hydroxyl group. After ingestion, it is decarboxylated to norepinephrine. It is more utilized in outpatient for hypotension particularly in Parkinson's disease. Its utility in ICU has not been established and is still less utilized than midodrine. 

The starting dose is 300 mg per day in the divided dose but can be increased up to 1800 mg per day in divided doses - usually thrice a day. Like midodrine, it can cause supine hypertension. 

It does not work in patients with chronic carbidopa use.

#hemodynamics

#pharmacology

References:

1. Biaggioni I, Arthur Hewitt L, Rowse GJ, Kaufmann H. Integrated analysis of droxidopa trials for neurogenic orthostatic hypotension. BMC Neurol 2017; 17:90. 

2. Kaufmann H, Freeman R, Biaggioni I, et al. Droxidopa for neurogenic orthostatic hypotension: a randomized, placebo-controlled, phase 3 trial. Neurology 2014; 83:328. 

3. Elgebaly A, Abdelazeim B, Mattar O, et al. Meta-analysis of the safety and efficacy of droxidopa for neurogenic orthostatic hypotension. Clin Auton Res 2016; 26:171. 

4. Kaufmann H, Norcliffe-Kaufmann L, Palma JA. Droxidopa in neurogenic orthostatic hypotension. Expert Rev Cardiovasc Ther 2015; 13:875.