Drug information of Alprostadil


Drug group:

Alprostadil is used to treat erectile dysfunction (impotence) and to help diagnose certain causes of this disorder. Alprostadil is also used to improve blood flow in newborn babies with a certain genetic heart condition. This alprostadil medication guide addresses only the adult male use of this medication in erectile disorders. Alprostadil relaxes blood vessels and muscles in the penis. This increases blood flow into the penis, causing an erection.

Mechanism of effect

Alprostadil causes vasodilation by means of a direct effect on vascular and ductus arteriosus (DA) smooth muscle, preventing or reversing the functional closure of the DA that occurs shortly after birth. This is because, as a form of prostaglandinE1 (PGE1) it has multiple effects on blood flow. This results in increased pulmonary or systemic blood flow in infants. In cyanotic congenital heart disease, alprostadil's actions result in an increased oxygen supply to the tissues.


Alprostadil (prostaglandin E1) is one of a family of naturally occurring acidic lipids with various pharmacologic effects. Vasodilation, inhibition of platelet aggregation, and stimulation of intestinal and uterine smooth muscle are among the most notable of these effects.


The absolute bioavailability of alprostadil has not been determined. Bound in plasma primarily to albumin (81% bound). 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.


Usual Adult Dose for Erectile Dysfunction INTRACAVERNOUS: 1 to 40 mcg intracavernous injection into the lateral penis given over 5 to 10 seconds Maximum dose: 3 times per week, with at least 24 hours between each use Usual Pediatric Dose for Patent Ductus Arteriosus 0.05 to 0.1 mcg/kg/min continuous IV infusion


Apnea is experienced by about 10 to 12% of neonates with congenital heart defects treated with Alprostadil Injection, USP. Apnea is most often seen in neonates weighing less than 2 kg at birth and usually appears during the first hour of drug infusion. Therefore, respiratory status should be monitored throughout treatment, and Alprostadil Injection, USP should be used where ventilatory assistance is immediately available.

Points of recommendation

Patient advice: Intracavernous: -Instruct patients to report any unusual adverse effects such as new or increased penile pain, penile bending, and/or nodule formation in the penile shaft. Intracavernous and Transurethral: -Advise patients to seek immediate medical assistance for any erection lasting longer than 6 hours. If not treated immediately, penile tissue damage and permanent loss of potency may occur. -Thoroughly instruct and train the patient in self-treatment technique prior to the patient beginning treatment at home. -The dose established with the physician should not be changed by the patient without consulting the physician. -Educate patients that use of this drug offers no protection from transmission of sexually transmitted or blood-borne diseases. -Caution patients to avoid activities, such as driving or hazardous tasks, where injury could result if hypotension or syncope occurred.

Pregnancy level


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