| 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. |
| Pharmacodynamics | Fenoldopam is an agonist at D1-like dopamine receptors, binds to α2-adrenoceptors, increasing renal blood flow. |
| Mechanism of action | Fenoldopam is a rapid-acting vasodilator. It is an agonist for D1-like dopamine receptors and binds with moderate affinity to α2-adrenoceptors. It has no significant affinity for D2-like receptors, α1 and β-adrenoceptors, 5HT1 and 5HT2 receptors, or muscarinic receptors. Fenoldopam is a racemic mixture with the R-isomer responsible for the biological activity. The R-isomer has approximately 250-fold higher affinity for D1-like receptors than does the S-isomer. In non-clinical studies, fenoldopam had no agonist effect on presynaptic D2-like dopamine receptors, or α or β -adrenoceptors, nor did it affect angiotensin-converting enzyme activity. Fenoldopam may increase norepinephrine plasma concentration. |
| Absorption | Not Available |
| Volume of distribution | Not Available |
| Protein binding | Not Available |
| Metabolism | Elimination is largely by conjugation, without participation of cytochrome P-450 enzymes. Methylation, glucuronidation, and sulfation are the main routes of conjugation. |
| Route of 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. |
| 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. |
| Clearance | Not Available |
| Toxicity | The most likely reaction of overdose would be excessive hypotension which should be treated with drug discontinuation and appropriate supportive measures. |