Alprostadil

The preferred route of administration for alprostadil injection, USP is continuous intravenous infusion into a large vein. Alternatively, alprostadil injection may be administered through an umbilical artery catheter placed at the ductal opening. Increases in blood pO2 (torr) have been the same in neonates who received the drug by either route of administration.

Begin infusion with 0.05 to 0.1 micrograms alprostadil per kilogram of body weight per minute. A starting dose of 0.1 micrograms per kilogram of body weight per minute is the recommended starting dose based on clinical studies; however, adequate clinical response has been reported using a starting dose of 0.05 micrograms per kilogram of body weight per minute. After a therapeutic response is achieved (increased pO2 in infants with restricted pulmonary blood flow or increased systemic blood pressure and blood pH in infants with restricted systemic blood flow), reduce the infusion rate to provide the lowest possible dosage that maintains the response. This may be accomplished by reducing the dosage from 0.1 to 0.05 to 0.025 to 0.01 micrograms per kilogram of body weight per minute. If response to 0.05 micrograms per kilogram of body weight per minute is inadequate, dosage can be increased up to 0.4 micrograms per kilogram of body weight per minute although, in general, higher infusion rates do not produce greater effects.

Dilution Instructions

To prepare infusion solutions, dilute 1 mL of alprostadil injection, USP with sodium chloride injection, USP or dextrose injection, USP. Undiluted alprostadil injection may interact with the plastic sidewalls of volumetric infusion chambers causing a change in the appearance of the chamber and creating a hazy solution. Should this occur, the solution and the volumetric infusion chamber should be replaced.

When using a volumetric infusion chamber, the appropriate amount of intravenous infusion solution should be added to the chamber first. The undiluted alprostadil injection should then be added to the intravenous infusion solution, avoiding direct contact of the undiluted solution with the walls of the volumetric infusion chamber.

Dilute to volumes appropriate for the pump delivery system available. Prepare fresh infusion solutions every 24 hours. Discard any solution more than 24 hours old.

Sample Dilutions and Infusion Rates to Provide a Dosage of 0.1 Micrograms per Kilogram of Body Weight per Minute Add 1 vial
(500 micrograms)
alprostadil to: Approximate
Concentration of
resulting solution
(micrograms/mL) lnfusion rate
(mL/min per kg)
(of body weight) 250 mL 2 0.05 100 mL 5 0.02 50 mL 10 0.01 25 mL 20 0.005 Example: To provide 0.1 micrograms/kilogram of body weight per minute to an infant weighing 2.8 kilograms using a solution of 1 vial alprostadil injection, USP in 100 mL of saline or dextrose: INFUSION RATE = 0.02 mL/min per kg × 2.8 kg = 0.056 mL/min or mL/hr.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.