Fenoldopam mesylate

Fenoldopam mesylate
INN
Drug class
Routes of administration	Intravenous
Pregnancy category
Bioavailability
Metabolism	Hepatic
Elimination half-life	5 minutes
Excretion	Urine
Legal status
CAS Number	67227-56-9
PubChem	3342
DrugBank	DB00800
ChemSpider	3225
KEGG	D07908

Fenoldopam Mesylate is a dopamine receptor agonist used primarily as an antihypertensive agent. It is marketed under the trade name Corlopam. Fenoldopam is unique in its class as it acts as a selective dopamine D1 receptor agonist, leading to vasodilation and a reduction in blood pressure.

Pharmacology

Fenoldopam is a benzazepine derivative that acts as a selective agonist at peripheral dopamine D1 receptors. Activation of these receptors results in vasodilation of renal, mesenteric, and coronary arteries, which leads to increased renal blood flow, natriuresis, and diuresis. This mechanism is beneficial in managing hypertensive emergencies and postoperative hypertension.

Mechanism of Action

Fenoldopam binds to dopamine D1 receptors, which are G-protein coupled receptors. Upon activation, these receptors stimulate adenylate cyclase, increasing intracellular cyclic AMP levels. This cascade results in the relaxation of vascular smooth muscle and subsequent vasodilation. Unlike other vasodilators, fenoldopam does not act on alpha or beta adrenergic receptors, making it a selective agent for dopamine D1 receptor pathways.

Pharmacokinetics

Fenoldopam is administered intravenously due to its rapid onset and short duration of action. It has a half-life of approximately 5 minutes, allowing for quick titration and control of blood pressure. The drug is extensively metabolized in the liver, and its metabolites are excreted primarily in the urine.

Clinical Use

Fenoldopam is indicated for the short-term management of severe hypertension, particularly in hypertensive emergencies and postoperative hypertension. It is preferred in situations where rapid, controlled reduction of blood pressure is necessary.

Dosage and Administration

Fenoldopam is administered as a continuous intravenous infusion. The initial dose is typically 0.1 mcg/kg/min, which can be titrated up to a maximum of 1.6 mcg/kg/min based on the patient's response and clinical condition. The infusion rate is adjusted every 15 minutes to achieve the desired blood pressure reduction.

Adverse Effects

Common adverse effects of fenoldopam include headache, flushing, dizziness, and nausea. Due to its vasodilatory effects, it can also cause hypotension and tachycardia. Rarely, it may lead to increased intraocular pressure, which is a consideration in patients with glaucoma.

Contraindications

Fenoldopam is contraindicated in patients with known hypersensitivity to the drug or its components. Caution is advised in patients with glaucoma or intraocular hypertension due to the potential for increased intraocular pressure.

Interactions

Fenoldopam may interact with other antihypertensive agents, leading to additive hypotensive effects. It should be used cautiously with beta-blockers, as the combination may result in excessive blood pressure reduction.

Conclusion

Fenoldopam Mesylate is a valuable agent in the management of acute severe hypertension due to its rapid onset and ability to selectively target dopamine D1 receptors. Its unique mechanism of action and pharmacokinetic profile make it suitable for use in critical care settings where precise blood pressure control is essential.