Alprostadil
(PGE ₁)
Alprostadil (Prostin VR Pediatric)
PGE ₁(Prostin VR Pediatric)
Alprostadil
(al- PROSS-tah-dill) Caverject Edex Muse Prostin VR Prostin VR Pediatric (Rx)

Classification: Prostaglandin

Action/Kinetics: Alprostadil is the naturally occurring acidic lipid prostaglandin E ₁. It relaxes smooth muscle of the ductus arteriosus leading to increased pulmonary blood flow with increased blood oxygenation and lower body perfusion. Clients with low pO ₂ values respond best. May also cause vasodilation, inhibit platelet aggregation, and stimulate both intestinal and uterine smooth muscle. When injected intracavernosally, alprostadil relaxes the trabecular cavernous smooth muscles and causes dilation of penile arteries. This results in increased arterial blood flow to the corpus cavernosa and thus swelling and elongation of the penis. Onset, systemic: 1.5-3 hr for acyanotic congenital heart disease and 15-30 min for cyanotic congenital heart disease. Time to peak effect: 3 hr for coarctation of the aorta and 1.5 hr for interruption of aortic arch. Duration: Closure of the ductus arteriosus usually begins 1-2 hr after infusion discontinued. Alprostadil is rapidly metabolized (80% in one pass) by oxidation in the lung, and metabolites are excreted by the kidney.

Uses: Diagnosis and treatment of erectile dysfunction (male impotence) due to neurologic, vascular, psychologic, or mixed causes. Prostin VR Pediatric is used in newborns with congenital heart defects to maintain patency of the ductus arteriosus. Investigational: Diagnostic peripheral arteriography. Treat atherosclerosis, gangrene, and pain due to peripheral vascular disease.

Contraindications: Respiratory distress syndrome. Conditions that predispose to priapism: sickle cell anemia or trait, multiple myeloma, leukemia. In clients with anatomic deformation of the penis or in those with penile implants. Use in women, children, newborns, or men for whom sexual activity is not advisable or is contraindicated. Use for sexual intercourse with a pregnant woman unless a condom is used. Hyaline membrane disease.

Side Effects: Respiratory: Apnea (in 10%-12% of neonates), especially in neonates less than 2 kg at birth; bronchial wheezing, bradypnea, hypercapnia, respiratory depression. Also, in adults, respiratory infection, flu syndrome, sinusitis, rhinitis, nasal congestion, cough. CNS: Fever, seizures hypothermia, jitteriness, lethargy, cerebral bleeding stiffness, hyperextension of the neck, irritability. CV: Flushing, especially after intra-arterial dosage, bradycardia, hypotension, tachycardia, edema, cardiac arrest, CHF, shock, arrhythmias. GI: Diarrhea, hyperbilirubinemia, gastric regurgitation. Renal: Hematuria, anuria. Skeletal: Cortical proliferation of long bones. Hematologic: Disseminated intravascular coagulation thrombocytopenia, anemia, bleeding. Miscellaneous: Sepsis, peritonitis hypoglycemia, hypokalemia or hyperkalemia.
Side effects when used for erectile dysfunction: Penile pain, prolonged erection, penile fibrosis, hematoma at injection site, penile disorders, including numbness, yeast infection, irritation, sensitivity, phimosis, pruritus, erythema, venous leak, penile skin tear, strange feeling in penis, discoloration of penile head, itch at tip of penis. Painful erection, abnormal ejaculation, penile rash, penile edema, priapism, hematoma, ecchymosis, urethral pain, urethral burning, urethral bleeding or spotting, testicular pain.

Laboratory Test Alterations: Bilirubin. Glucose, serum calcium. or Potassium.

Overdose Management: Symptoms: Apnea bradycardia, flushing, hypotension, pyrexia. Treatment: Reduce rate of infusion if symptoms of hypotension or pyrexia occur; discontinue infusion if symptoms of apnea or bradycardia occur.

Drug Interactions: Cyclosporine / Cyclosporine blood levels Heparin, Warfarin / Bleeding after intracavernosal injection

How Supplied: Injection: 0.5 mg/mL; Pellet: 125 mcg, 250 mcg, 500 mcg, 1000 mcg; Powder for Injection: 10 mcg/vial, 20 mcg/vial; 40 mcg/vial; Urethral Suppository: 125 mcg, 250 mcg, 500 mcg, 1000 mcg

Dosage
?Continuous IV Infusion or Umbilical Artery Maintain patency of ductus arteriosus.
Initial: 0.05-0.1 mcg/kg/min; then, after response achieved, decrease infusion rate to lowest dose that will maintain response (e.g., 0.1-0.05 to 0.025-0.01 mcg/kg/min). NOTE: If 0.1 mcg/kg/min is insufficient, dosage can be increased up to 0.4 mcg/kg/min.
?Intracavernosal Erectile dysfunction due to vascular, psychogenic, or mixed etiology.
Individualize the dose for each client by careful titration. Initial: 2.5 mcg. If there is a partial response, increase the dose by 2.5 mcg to 5 mcg and then in increments of 5-10 mcg, depending on the erectile response, until a dose is reached that results in an erection suitable for intercourse but not exceeding 1 hr in duration. If there is no response to the initial 2.5-mcg dose, the second dose may be increased to 7.5 mcg, followed by increments of 5 to 10 mcg. Maximum dose: 60 mcg. Do not give the drug more than 3 times/week with at least 24 hr between each dose.
Erectile dysfunction due to pure neurogenic etiology (spinal cord injury).
Initial: 1.25 mcg. The dose may be increased by 1.25 mcg to 2.5 mcg, followed by an increment of 2.5 mcg to a dose of 5 mcg. The dose may be increased in 5-mcg increments until a dose is reached that produces an erection suitable for intercourse and not exceeding 1 hr in duration.