For the long-term intravenous treatment of primary pulmonary hypertension and pulmonary hypertension associated with the scleroderma spectrum of disease in NYHA Class III and Class IV patients who do not respond adequately to conventional therapy.
Epoprostenol has two major pharmacological actions: (1) direct vasodilation of pulmonary and systemic arterial vascular beds, and (2) inhibition of platelet aggregation. In animals, the vasodilatory effects reduce right and left ventricular afterload and increase cardiac output and stroke volume. The effect of epoprostenol on heart rate in animals varies with dose. At low doses, there is vagally mediated brudycardia, but at higher doses, epoprostenol causes reflex tachycardia in response to direct vasodilation and hypotension. No major effects on cardiac conduction have been observed. Additional pharmacologic effects of epoprostenol in animals include bronchodilation, inhibition of gastric acid secretion, and decreased gastric emptying. No available chemical assay is sufficiently sensitive and specific to assess the in vivo human pharmacokinetics of epoprostenol.
Mode of Action:
Prostaglandins are present in most body tissues and fluids and mediate many biological functions. Epoprostenol (PGI2) is a member of the family of prostaglandins that is derived from arachidonic acid. The major pharmacological actions of epoprostenol is ultimately inhibition of platelet aggregation. Prostacyclin (PGI2) is released by healthy endothelial cells and performs its function through a paracrine signaling cascade that involves G protein-coupled receptors on nearby platelets and endothelial cells. The platelet Gs protein-coupled receptor (prostacyclin receptor) is activated when it binds to PGI2. This activation, in turn, signals adenylyl cyclase to produce cAMP. cAMP goes on to inhibit any undue platelet activation (in order to promote circulation) and also counteracts any increase in cytosolic calcium levels which would result from thromboxane A2 (TXA2) binding (leading to platelet activation and subsequent coagulation). PGI2 also binds to endothelial prostacyclin receptors and in the same manner raise cAMP levels in the cytosol. This cAMP then goes on to activate protein kinase A (PKA). PKA then continues the cascade by phosphorylating and inhibiting myosin light-chain kinase which leads to smooth muscle relaxation and vasodilation. Notably, PGI2 and TXA2 work as physiological antagonists.
Epoprostenol is metabolized to 2 primary metabolites: 6-keto-PGF1α (formed by spontaneous degradation) and 6,15-diketo-13,14-dihydro-PGF1α (enzymatically formed), both of which have pharmacological activity orders of magnitude less than epoprostenol in animal test systems. Fourteen additional minor metabolites have been isolated from urine, indicating that epoprostenol is extensively metabolized in humans.
Symptoms of overdose are extensions of its dose-limiting pharmacologic effects and include flushing, headache, hypotension, nausea, vomiting, and diarrhea. Most events were self-limiting and resolved with reduction or withholding of epoprostenol. Single intravenous doses at 10 and 50 mg/kg (2703 and 27,027 times the recommended acute phase human dose based on body surface area) were lethal to mice and rats, respectively. Symptoms of acute toxicity were hypoactivity, ataxia, loss of righting reflex, deep slow breathing, and hypothermia.
Products currently covered by valid US Patents are offered for R&D use in accordance with 35 USC 271(e)+A13(1). Any patent infringement and resulting liability is solely at buyer risk.
API’s From Quality Manufacturers:
Cost effective materials based on specific requirements
Small quantities for initial research and larger development quantities towards product commercialization
Technical packages, letters of access to filed DMFs