Alprostadil (also called Prostin VR Pediatric, prostaglandin E1 or PGE1) is a platelet and vasodilator inhibiting agent used to treat heart, blood vessel and lung problem in infants. It belongs to a group of compounds called autacoids (autacoids work as local hormones) and they work by temporarily keeping the patent ductus arteriosus (blood vessel in the heart) open during a palliative or corrective procedure in neonates with congenital heart defects. The drug is administered intra-arterially or intravenously under the supervision of the infant’s doctor. The drug is synthesized from the seminal vesicle tissues of sheep.
Along with its intended effects, alprostadil may cause some unwanted side effects. These side effects may vary from patient to patient and medical attention is recommended based on the severity.
Some of these side effects may not require medical attention and will often go away as the body adjusts to medication. Also, your infant's doctor may be able to tell you how to manage the mild side effects at home. That said, be sure to call your doctor if the side effects are severe. You may also report the side effects to the FDA through their toll-free line on 1-800-FDA-1088.
5 mcg/mL, 10 mcg/mL, 20 mcg/mL, 40 mcg/mL powder for injection. It is also available in 250mcg, 500mcg and 1000mcg pellets.
Alprostadil injection is administered through continuous intravenous infusion into a large vein. It can also be administered through the umbilical artery catheter located at the ductal opening.
The recommended starting dose is 0.05 to 0.1 mcg per kilogram of body weight per minute. After achieving a therapeutic response, the dosage can be reduced to 0.025 to 0.01 mcg per kilogram of body weight per minute. However, if response to 0.025 mcg per kilogram of body weight is inadequate, then the dosage can be adjusted to 0.04 mcg per kilogram of body weight per minute although, generally, higher infusion rates do not yield greater effects.
For infusion, 1 mL of the concentrate labeled as containing 500 mcg of alprostadil should be diluted in 0.9% Sodium Chloride injection to produce 2 to 20 mcg/mL of the solution depending on the infant’s needs and the controlled-infusion apparatus used. If you are using an apparatus with a volumetric infusion chamber, add the right amount of diluent to the chamber first before adding 1 mL of the concentrate. Exercise care to avoid getting the concentrate into direct contact with the wall of the plastic volumetric infusion chamber. It is recommended that diluted alprostadil solution be freshly prepared every 24 hours and any unused solution discarded.
Alprostadil overdose may be characterized by apnea, pyrexia, bradycardia, flushing and hypotension. Infusion should be discontinued and appropriate medical treatment administered in an event of bradycardia or apnea. Caution should be observed when restarting the infusion. In case of hypotension or pyrexia, reduce infusion rate until these symptoms subside. Flushing usually occurs when the intraarterial catheter is incorrectly placed. Reposition the catheter to remedy the symptom.
The interaction between these two medications is minor. The concomitant use of alprostadil and an antihypertensive agent like angiotensin II receptor antagonist may cause additive hypotension. The same reaction can be experienced when alprostadil is used in combination with angiotensin-converting enzyme inhibitors.
Other medications that interact with alprostadil include Atenolol, Nadolol, Chlorthalidone, Beta-blockers like Betaxolol and bisoprolol.
If your baby is on any other medications or supplements, be sure to speak to your doctor before administering this drug. Based on a case by case circumstance, your doctor will discuss the following with you:
Apnea cases have been reported in approximately 10% to 12% of infants and neonates with congenital heart disease treated using alprostadil. Thus, the infant’s respiratory status should be closely monitored during alprostadil treatment.
In some cases, intravenous administration of alprostadil to infants may trigger GI obstruction similar to antral hyperplasia. The duration of treatment as well as drug accumulation are linked to this adverse effect. Careful monitoring for signs of gastric outlet obstruction and antral hyperplasia is recommended in neonates on alprostadil therapy for more than 120 hours.
Intravenous infusion of alprostadil is not recommended in neonates with neonatal respiratory distress syndrome. In such neonates, the ductus arteriosus should close to prevent an overload of the pulmonary circulation.
Alprostadil works by inhibiting platelet aggregation. As such, it tends to increase the risk of bleeding. It should, therefore, be used cautiously in neonates who are prone to bleeding.
Alprostadil infusion for purposes of maintaining patency of the ductus arteriosus can also cause hypotension. Thus, neonates on this medication should be closely monitored for a fall in blood pressure.
Alprostadil infusion should be administered for the shortest time possible and using the smallest possible dose that will produce the desired effects. The risk of alprostadil’s long-term infusion should be gauged against desired benefits that infants who are severely ill may derive from the medication.
Alprostadil medication should only be administered by a trained healthcare provider within the hospital setting.
If your infant has any underlying lung problem, discuss this with your infant’s doctor to explore how the treatment may affect the infant’s medical condition, how this condition may affect the dosing and effectiveness of the medication and whether there is a need for special monitoring.
Discuss any other hear problems that your baby might be having before the onset of treatment. All arterial pressure should be intermittently monitored using umbilical artery catheter, Doppler transducer or auscultation. A decrease in infusion should be effected immediately should there be a fall in arterial pressure.
Alprostadil injection should be diluted before administration. Read the dilution instructions on the drug’s label.
The drug should be stored at 2-degree to 8-degree centigrade in a dry place. All products containing particulate matter, which are discolored or cloudy should be discarded. Reconstituted medicine should be used immediately (within 24 hours) and unused portions disposed of. Protect all medication from direct sunlight and keep out of reach of children.
Do not dispose of unused medication in wastewater (e.g in the toilet or kitchen sink) or household garbage. Ask your doctor or pharmacist how to get rid of medications that you no longer need or are expired.
Alprostadil belongs to the pharmacologic class prostaglandin. It is administered intravenously to treat certain lung, heart and blood vessel conditions in newborn babies. It is used to temporarily keep the blood vessel in the infant’s heart (ductus arteriosus) open before surgery. Alprostadil should only be administered under strict supervision of your child’s physician.
Before using the medication, it is important that the risks involved are weighed against the desired benefits. This is a decision that your doctor must make with your approval. Before using the drug, tell the doctor if the infant has ever had any allergic or unusual reactions to alprostadil or any other medication. Also, tell the doctor if the infant has any other types of allergies such as dyes, food, preservatives and animals.
The recommended starting dosage of alprostadil is calculated based on the infant’s body weight. When the desired effect on the ductus arteriosus is realized, the infusion rate should be reduced to the lowest possible dose while maintaining the desired effect. Other factors that may affect the dosage include the infant’s medical condition as well as other medications that they are presently receiving.
Alprostadil should not be administered to infants who are allergic to it or to any of the ingredients present in the medication. It is also not recommended for infants with preexisting lung or heart conditions which, in the doctor’s opinion, would endanger their lives when put on this medication.