A dopamine D1 receptor agonist that is used as an antihypertensive agent. It lowers blood pressure through arteriolar vasodilation. [PubChem]
Indication
For the in-hospital, short-term (up to 48 hours) management of severe hypertension when rapid, but quickly reversible, emergency reduction of blood pressure is clinically indicated, including malignant hypertension with deteriorating end-organ function.
Pharmacology
Fenoldopam is an agonist at D1-like dopamine receptors, binds to α2-adrenoceptors, increasing renal blood flow.
Toxicity
The most likely reaction of overdose would be excessive hypotension which should be treated with drug discontinuation and appropriate supportive measures.
Affected Organisms
Humans and other mammals
Biotransformation
Elimination is largely by conjugation, without participation of cytochrome P-450 enzymes. Methylation, glucuronidation, and sulfation are the main routes of conjugation.
Half Life
The elimination half-life is about 5 minutes in mild to moderate hypertensives, with little difference between the R (active) and S isomers.
Elimination
Radiolabeled studies show that about 90% of infused fenoldopam is eliminated in urine, 10% in feces. Elimination is largely by conjugation, without participation of cytochrome P-450 enzymes. Only 4% of the administered dose is excreted unchanged.
