PGE1 - General Information
PGE1 is produced endogenously and 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 results in increased pulmonary or systemic blood flow in infants. In infants, it is used for palliative, not definitive, therapy to temporarily maintain the patency of the ductus arteriosus until corrective or palliative surgery can be performed in neonates who have congenital heart defects and who depend upon the patent ductus for survival. In adults, it is used for the treatment of erectile dysfunction due to neurogenic, vasculogenic, psychogenic, or mixed etiology.
Pharmacology of PGE1
PGE1 (prostaglandin E1) is produced endogenously to relax vascular smooth muscle and cause vasodilation. In adult males, the vasodilatory effects of alprostadil on the cavernosal arteries and the trabecular smooth muscle of the corpora cavernosa result in rapid arteriolar inflow and expansion of the lacunar spaces within the corpora. As the expanded corporal sinusoids are compressed against the tunica albuginea, venous outflow through the subtunical vessels is impeded and penile rigidity develops. This is referred to as the corporal veno-occlusive mechanism. In infants, the vasodilatory effects of alprostadil increase pulmonary or systemic blood flow.
PGE1 for patients
Caverject Information for the Patient: The patient should be instructed to transfer the solution from the pharmacy to his home freezer or refrigerator as soon as possible. Brief (2 hours or less) exposure to conditions as warm as 25°C (77°F) will not harm the product.
To ensure safe and effective use of CAVERJECT, the patient should be thoroughly instructed and trained in the self-injection technique before he begins intracavernosal treatment with CAVERJECT at home. The desirable dose should be established in the physician's office.
Any ampoule containing sterile solution with precipitates or discoloration should be discarded. The ampoule is designed for one use only and should be discarded after withdrawal of proper volume of the solution. Needles must be properly discarded after use; they must not be re-used or shared with other persons. Patient instructions for administration are included in each package of CAVERJECT.
The dose of CAVERJECT that is established in the physician's office should not be changed by the patient without consulting the physician. The patient may expect an erection to occur within 5 to 20 minutes. A standard treatment goal is to produce an erection lasting no longer than 1 hour. Generally, CAVERJECT should be used no more than 3 times per week, with at least 24 hours between each use.
Patients should be aware of possible side effects of therapy with CAVERJECT; the most frequently occurring is penile pain after injection, usually mild to moderate in severity. A potentially serious adverse reaction with intracavernosal therapy is priapism. Accordingly, the patient should be instructed to contact the physician's office immediately or, if unavailable, to seek immediate medical assistance if an erection persists for longer than 4 hours.
The patient should report any penile pain that was not present before or that increased in intensity, as well as the occurrence of nodules or hard tissue in the penis to his physician as soon as possible. As with any injection, an infection is a possibility. Patients should be instructed to report to the physician any penile redness, swelling, tenderness or curvature of the erect penis. The patient must visit the physician's office for regular checkups for assessment of the therapeutic benefit and safety of treatment with CAVERJECT.
Note: Use of intracavernosal CAVERJECT offers no protection from the transmission of sexually transmitted diseases. Individuals who use CAVERJECT should be counseled about the protective measures that are necessary to guard against the spread of sexually transmitted diseases, including the human immunodeficiency virus (HIV).
The injection of CAVERJECT can induce a small amount of bleeding at the site of injection. In patients infected with blood-borne diseases, this could increase the risk of transmission of blood-borne diseases between partners.
In clinical trials, concomitant use of agents such as antihypertensive drugs, diuretics, antidiabetic agents (including insulin), or non-steroidal anti-inflammatory drugs had no effect on the efficacy or safety of CAVERJECT.
Patient instructions for Caverject
IMPOTENCE: CAUSES AND TREATMENTS
There are several causes of impotence, a condition known medically as erectile dysfunction. These include: medications that you may be taking for other conditions, impaired blood circulation in the penis, nerve damage, emotional problems, excessive smoking or alcohol use, use of street drugs, and hormonal imbalances. Often, impotence is due to more than one cause.
Treatments for impotence include: switching medications (if you are taking a medication that causes impotence), administration of hormones, penile injections, use of medical devices that produce an erection, surgical procedures to correct blood flow in the penis, penile implants, and psychological counseling. Your doctor has selected CAVERJECT to treat your impotence. Your doctor can also discuss other available treatments. You should not stop taking any prescription medications, unless told to do so by your doctor
USE OF CAVERJECT
CAVERJECT is injected into a specific area of the penis and should produce an erection in 5 to 20 minutes. The erection should last for about 1 hour. Generally, you should not use CAVERJECT more than 3 times a week, with at least 24 hours between uses.
Who Should Not Use CAVERJECT?
Men who have conditions that might result in long-lasting erections should not use CAVERJECT. Some of these conditions include: sickle cell anemia or trait, leukemia, and tumor of the bone marrow (multiple myeloma). Men with penile implants, or an abnormally formed penis, or who have been advised not to engage in sexual activity should not use CAVERJECT. CAVERJECT should not be used by women or children.
What are the Risks of Using CAVERJECT?
Erections that last more than 4 hours can cause serious and permanent damage. Call your doctor or seek professional help immediately if you still have an erection 4 hours after injection.
The most common side effect of CAVERJECT is mild to moderate pain after injection. About onethird of patients report this effect.
Call your doctor if you notice any redness, lumps, swelling, tenderness, or curving of the erect penis.
A small amount of bleeding at the injection site may occur. Tell your doctor if you have a condition or are taking a medicine that interferes with blood clotting.
NOTE: CAVERJECT offers no protection from the transmission of sexually transmitted diseases such as HIV (the virus that causes AIDS). Small amounts of bleeding at the injection site can increase the risk of transmission of blood-borne diseases between partners.
There is no approved injectable treatment using multiple drug components or "cocktails" for erectile dysfunction. Moreover, there are no data on the efficacy and safety of these combinations.
- CAVERJECT Injection is distributed and stored in the pharmacy as a frozen pack, which you should place in your freezer or refrigerator as soon as possible. Brief (2 hours or less) exposure to conditions as warm as 25°C (77°F) will not harm your medicine. If placed in your refrigerator, it must be used within 7 days (see #2 below).
- Store unused packs of CAVERJECT Injection in the unopened foil wrapping in your freezer at -20° to -10°C (-4° to 14°F) for no longer than 3 months. During this 3-month period, CAVERJECT Injection may be moved to and kept in a refrigerator at 2° to 8°C (36° to 46°F) for up to 7 days. Once refrigerated, it must be used within 7 days or discarded; do not refreeze the ampoule.
- Once removed from the foil wrapping, use the solution in the ampoule immediately after allowing it to warm to room temperature or discard it.
- After opening the ampoule, CAVERJECT Injection should be used immediately.
- During travel, care should be taken to avoid allowing the medicine to be stored at temperatures above 8°C (46°F). Therefore, do not store in checked luggage during air travel or leave in a closed automobile. Transporting your medicine in a cooler with wet ice is recommended. Brief (2 hours or less) exposure to conditions as warm as 25°C (77°F) will not harm your medicine. However, it should be replaced in the refrigerator or freezer as soon as practical.
There is a technical leaflet discussion of CAVERJECT written for health-care professionals that your pharmacist can let you read.
More information about erectile dysfunction and its treatment is available from the National Institutes of Health (Washington, DC), the American Foundation for Urological Diseases (Baltimore, MD), or the Impotence Institute of America (Washington, DC).
PREPARING AND INJECTING CAVERJECT
You must be properly instructed and trained in the injection technique by your doctor before using CAVERJECT.
Before using CAVERJECT, talk to your doctor about what to expect when using it, possible side effects, and what to do if side effects occur. Your dose has been selected for your individual needs. Do not change your dose without consulting your doctor. If you are not sure of the volume or dose to be used, talk to your doctor or pharmacist.
Follow these instructions exactly to prepare and inject a sterile dose of CAVERJECT. Use the needle, syringe and ampoule only once, then safely discard the supplies and any unused solution (see the "Disposal of Injection Materials" section of these instructions).
Along with an ampoule of CAVERJECT Injection, you will need a needle, a syringe, and an alcohol swab. A complete set of these items is available from your doctor or pharmacist, or is supplied in the CAVERJECT Companion Pack.
Two needles of different size are provided in the Companion Pack; a 1/2", 27 gauge needle and a thinner 1/2", 30 gauge needle. Your doctor should advise you on the appropriate needle to use for your injection.
CAVERJECT comes in ampoules containing 10, 20 and 40 micrograms. MAKE SURE YOU HAVE THE RIGHT STRENGTH AMPOULE OF CAVERJECT.
A. Caverject Injection and injection supplies
Prepare the Dose
- Remove an ampoule of CAVERJECT Injection from the foil wrapping. Allow the ampoule contents to warm to room temperature. The ampoule should not be cool to the touch. Do not immerse in water. Do not microwave. Once removed from the foil wrapping, use the solution in the ampoule immediately after allowing it to warm to room temperature or discard it.
- Wash your hands thoroughly, and dry them with a clean towel.
- Remove the syringe from its packaging by handling the syringe barrel only. Remove the syringe tip cover, pull the plunger back about half way, and set the syringe aside on a clean surface. Do not touch the tip of the syringe.
- Shake the ampoule vigorously for at least 30 seconds. Next, hold the shorter tab closest to the neck of the ampoule and shake it downward with a quick snap to clear any solution from the neck.
- Holding the ampoule by the side edges, twist the top of the ampoule and lift upward to remove. Make sure the open ampoule does not touch your hands or any other surface.
- While continuing to hold the ampoule upright, securely attach to the tip of the syringe, push and twist in a clockwise fashion to assure a snug fit.
- With the ampoule snugly attached, point the syringe upward, push the plunger to expel air in the syringe, and slowly pull back the syringe plunger until all of the solution is removed from the ampoule. DO NOT USE THE SOLUTION IF IT IS CLOUDY, COLORED OR CONTAINS PARTICLES.
- If there are air bubbles, gently tap the syringe barrel until they float to the top of the solution. Holding the syringe upright, push the syringe plunger until it is slightly below the correct volume mark for the dose prescribed by your doctor. This will expel any air and most of the excess solution back into the ampoule.
- Remove the ampoule from the syringe, place the syringe tip cover on the syringe and set the syringe on a clean surface.
- Two needles of different size are provided in the Companion Pack; a 1/2", 27 gauge needle and a thinner 1/2", 30 gauge needle. Your doctor should advise you on the appropriate needle to use for your injection.
- Remove the selected needle from its package by handling the needle cover only and set on a clean surface.
- Remove the tip from the syringe and attach the needle to the syringe with a twisting movement in a clockwise fashion to assure a tight fit.
- Grasp the syringe barrel (not the plunger) and carefully remove the needle cover. Do not touch the exposed needle with your hands or any surface.
- Holding the syringe upright, apply extremely gentle upward pressure on the syringe plunger until liquid appears at the tip of the needle. If the syringe plunger is still below the correct volume mark for the dose prescribed by your doctor, any excess solution may be expelled into the open ampoule.
- Place the needle cover over the needle and set the syringe down on a level surface.
Select Injection Site
- CAVERJECT will be injected into a corpus cavernosum (spongy tissue) of the penis. One corpus cavernosum runs the length of the right side of the penis. Another corpus cavernosum runs the length of the left side of the penis.
- Choose an injection site on one side of the shaft of the penis. AVOID VISIBLE BLOOD VESSELS.
- WITH EACH USE OF CA VERJECT, ALTERNATE THE SIDE OF THE PENIS AND VARY THE SITE OF THE INJECTION.
Inject Your Dose of CAVERJECT
- You should be sitting upright or slightly reclined when injecting CAVERJECT.
- If your penis is not cir cumcised, pull the foreskin back. Holding the head of your penis with your thumb and forefinger, stretch it lengthwise along your thigh so that you can clearly see the selected injection site.
- Clean the injection site with a new alcohol swab. Do not discard this swab, you will need to use it again (see step 7).
- Remove the cover fr om the needle. Reposition the penis firmly against your thigh as in step 2 to keep it from moving during the injection.
- Hold the syringe between your thumb and index finger. Using a steady motion, push the needle straight into the selected site until the metal part of the needle is almost entirely in the penis.
- Holding the syringe bar rel between two fingers, move your thumb or finger to the top of the plunger and, with a steady motion, push down on the plunger so that the entire volume of CAVERJECT is slowly injected.
- Grasp the syringe bar rel and pull the needle out of your penis. APPLY PRESSURE TO THE INJECTION SITE WITH THE ALCOHOL SWAB FOR ABOUT 5 MINUTES OR UNTIL ANY BLEEDING STOPS.
Disposal of Injection Materials
After use, dispose of all injection materials safely. Your pharmacist may be able to supply a disposal box especially for syringes and needles. Do not reuse or share needles or syringes. As with all prescription medicines, do not allow anyone else to use your medicine.
Prostin VR Pediatric Sterile Solution
No drug interactions have been reported between Prostin VR Pediatric and the therapy standard in neonates with restricted pulmonary or systemic blood flow. Standard therapy includes antibiotics, such as penicillin and gentamicin; vasopressors, such as dopamine and isoproterenol; cardiac glycosides; and diuretics, such as furosemide.
The potential for pharmacokinetic drug-drug interactions between alprostadil and other agents has not been formally studied.
Alprostadil should not be used in patients who have a known hypersensitivity to the drug, in patients who have conditions that might predispose them to priapism, such as sickle cell anemia or trait, multiple myeloma, or leukemia, or in patients with anatomical deformation of the penis, such as angulation, cavernosal fibrosis, or Peyronie's disease. Patients with penile implants should not be treated with Alprostadil.
Alprostadil should not be used in women or children and is not for use in newborns.
Alprostadil should not be used in men for whom sexual activity is inadvisable or contraindicated.
Additional information about PGE1
PGE1 Indication: For palliative, not definitive, therapy to temporarily maintain the patency of the ductus arteriosus until corrective or palliative surgery can be performed in neonates who have congenital heart defects and who depend upon the patent ductus for survival. Also for the treatment of erectile dysfunction due to neurogenic, vasculogenic, psychogenic, or mixed etiology.
Mechanism Of Action: PGE1 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 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. In infants with interrupted aortic arch or very severe aortic coarctation, alprostadil maintains distal aortic perfusion by permitting blood flow through the DA from the pulmonary artery to the aorta. In infants with aortic coarctation, alprostadil reduces aortic obstruction either by relaxing ductus tissue in the aortic wall or by increasing effective aortic diameter by dilating the DA. In infants with these aortic arch anomalies, systemic blood flow to the lower body is increased, improving tissue oxygen supply and renal perfusion. When administered by intracavernosal injection or as an intraurethral suppository, alprostadil acts locally to relax the trabecular smooth muscle of the corpora cavernosa and the cavernosal arteries. Swelling, elongation, and rigidity of the penis result when arterial blood rapidly flows into the corpus cavernosum to expand the lacunar spaces. The entrapped blood reduces the venous blood outflow as sinusoids compress against the tunica albuginea.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Alprostadil
Synonyms: Not Available
Drug Category: Fibrinolytic Agents; Platelet Aggregation Inhibitors; Vasodilator Agents
Drug Type: Small Molecule; Approved; Investigational
Absorption: The absolute bioavailability of alprostadil has not been determined.
Toxicity (Overdose): Oral, mouse: LD50 = 186 mg/kg; Oral, rat: LD50 = 228 mg/kg. Apnea, bradycardia, pyrexia, hypotension, and flushing may be signs of drug overdosage.
Protein Binding: Bound in plasma primarily to albumin (81% bound) and to a lesser extent alpha-globulin IV-4 fraction (55% bound).
Biotransformation: 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.
Half Life: 5 to 10 minutes (after a single dose), in healthy adults and neonates.
Dosage Forms of PGE1: Suppository Urethral
Chemical IUPAC Name: 7-[(1R,2R,3R)-3-hydroxy-2-[(3S)-3-hydroxyoct-1-enyl]-5-oxocyclopentyl]heptanoic acid
Chemical Formula: C20H34O5
Alprostadil on Wikipedia: https://en.wikipedia.org/wiki/Alprostadil
Organisms Affected: Humans and other mammals