Alprostadil

Absorption	The absolute bioavailability of alprostadil has not been determined.
Volume of distribution	Not Available
Protein binding	Bound in plasma primarily to albumin (81% bound) and to a lesser extent alpha-globulin IV-4 fraction (55% bound).
Metabolism	Alprostadil must be infused continuously because it is very rapidly metabolized. As much as 80% of the circulating alprostadil may be metabolized in one pass through the lungs, primarily by beta- and omega-oxidation.
Route of elimination	Alprostadil must be infused continuously because it is very rapidly metabolized. As much as 80% of the circulating alprostadil may be metabolized in one pass through the lungs, primarily by β- and ω-oxidation. The metabolites are excreted primarily by the kidney, and excretion is essentially complete within 24 hours after administration.
Half life	5 to 10 minutes (after a single dose), in healthy adults and neonates.
Clearance	Not Available
Toxicity	Oral, mouse: LD50 = 186 mg/kg; Oral, rat: LD50 = 228 mg/kg. Apnea, bradycardia, pyrexia, hypotension, and flushing may be signs of drug overdosage.
Affected organisms	Humans and other mammals