| Alprostadil Pharmacology |
| Alprostadil |
| About Alprostadil |
| Prostaglandin E1, Vasodilator. |
| Mechanism of Action of Alprostadil |
| Patent ductus arteriosus: Alprostadil is a prostaglandin E1 analogue which maintains patency of the ductus arteriosus of fetus. After birth, prostaglandin production falls and the ductus closes. When there is congenital heart defect, it is necessary that the ductus remain patent until corrective surgery can be accomplished. In such conditions Alprostadil maintains patency pending surgery. Erectile dysfunction: Alprostadil produces vasodilatation. It increases blood flow to the penis by expanding blood vessels (cavernosal arteries). This allows blood flow to the lacunar spaces of the penis and produce erection. Alprostadil is used to produce erections in some men who need treatment for erectile dysfunction (sexual impotence). This medicine causes an erection because it increases the blood flow to the penis. Alprostadil injection should not be used as a sexual aid by men who do not have erectile dysfunction. If the medicine is not used properly, permanent damage to the penis and loss of the ability to have erections could result. |
| Pharmacokinets of Alprostadil |
| Absorption: It is administered as intravenous infusion and is completely absorbed. Distribution: Alprostadil is rapidly distributed throughout the body. Metabolism: It is metabolised by oxidation in the lung. Excretion: Alprostadil and its metabolites are excreted mainly in the urine. |
| Onset of Action for Alprostadil |
| 20minutes |
| Duration of Action for Alprostadil |
| N/A |
| Half Life of Alprostadil |
| N/A |
| Side Effects of Alprostadil |
| 1. Apnea, 2.Hypotension, 3.Bradycardia, 4.Tachycardia, 5.Cardiac arrest, 6.Edema, 7.Tachycardia, 8.Diarrhoea, 9.Hypokalaemia, 10.Flushing, 11.Fever, 12.Disseminated intravascular coagulation In erectile dysfunction: 1. Dizziness, 2. Faintness, 3. Pelvic pain, 4. Flu-like symptoms, 5. Redness, 6. Swelling, 7. Tenderness, 8. Unusual curving of the erect penis, 9. Pain on injection site, 10.Bleeding, 11.Painful erection, 12.Stinging of urethra, (suppository only), 13.Mild bleeding or spotting from urethra (suppository only); |
| Contra-indications of Alprostadil |
| 1. Hypersensitivity to Alprostadil, 2. Hyaline membrane disease, 3. Patients with penile implants. |
| Special Precautions while taking Alprostadil |
| 1.Patent ductus arteriosus 2.Neonates with bleeding disorder 3.Erectile dysfunction:Erection lasts longer than 4 hours, 4.Anemia, Sickle cell disease, leukemia 5.Renal impairment 6.Liver diseases 7.Sexually transmitted diseases 8.Human immunodeficiency virus (HIV) infection 9.Chronic obstructive pulmonary diseases 10.Use a condom when having sexual intercourse with a pregnant female (Alprostadil suppository) |
| Pregnancy Related Information |
| Contraindicated. |
| Old Age Related Information |
| Contraindicated. |
| Breast Feeding Related Information |
| Contraindicated. |
| Children Related Information |
| Contraindicated. |
| Indications for Alprostadil |
| 1. Patent ductus arteriosus, 2. Impotence. |
| Interactions for Alprostadil |
| There is no specific interaction. |
| Typical Dosage for Alprostadil |
| As intravenous infusion Maintenance of patency of ductus arteriosus: Infants: 0.05 – 0.1 mcg/kg body weight/ minute after sufficient therapeutic response is obtained then reduce the dose to lowest dose that will maintain response. For the treatment of erectile dysfunction: For injection dosage form (intracavernous injection or injection into the penis) Adults: 1.25-60 micrograms (mcg) injection as a single dose once a day. Inject this medicine very slowly into penis 10 – 30 minutes before intercourse. Allow five to ten seconds to completely inject the dose. It produces an erect penis within 5-20 minutes of injection. Do not inject more than one dose within 24hours. Do not use this medicine for more than 2 days in a row or more than3 times a week. For suppository dosage form: Adults: 125, 250, 500, or 1000 mcg as a single dose once a day (dose is determined by the doctor). Insert this medicine into the urethra 10- 30minutes before intercourse. Do not insert more than two doses within twenty-four hours. For patent ductus arteriosus: The drug is administered by health care professionals. For erectile dysfunction: Insertion of suppositories: Before inserting the suppository, you should urinate. Wash hands completely before using Alprostadil and to clean the area of the penis that will be injected before the needle is inserted. Remove the delivery device containing the suppository from the foil. Remove the cap from the applicator stem. Stretch penis upward to extend its length, pressing penis top and bottom. Gently insert the delivery stem up to its collar into urethra (located at the top of the penis). If you have pain or a pulling feeling in the penis, withdraw the device and start again. Press the button down slowly as far as it will go. This will helping in releases of the suppository into the urethra. After holding the delivery device within your penis still for 5 seconds, carefully rock the penis and delivery device as a unit from side to side. This helps remove the suppository from the device. Remove the delivery device while your penis is upright. Look at the device to make sure that the suppository was completely released. Repeat the process if a part of the suppository remains in the device. After the suppository is completely released, roll your penis between your hands for 10 seconds. This helps to dissolve the suppository. If you feel any stinging, continue this motion to help stop it. Sitting, standing, or walking for 10 minutes while an erection is developing helps increase the blood flow to your penis to gain a proper erection. Application of injection: Clean the injection site with alcohol. Remove the cover from the needle and hold the needle at a 90-degree angle to the place of injection. Insert the needle until almost all of the metal part of the needle is inserted into the penis. Press the plunger down slowly, taking 5 to 10 seconds to release the dose into the penis. The injection is usually not painful. If the injection is very painful or if you notice bruising or swelling at the place of injection, that means you are injecting the medicine under the skin. Stop, withdraw the needle, and reposition it properly before continuing with the injection. After you have completed the injection, put pressure on the place of injection for about 5 minutes or until any bleeding stops. This will prevent bruising. Then massage your penis as instructed by your doctor. This helps the medicine spread to all parts of the penis, so that the medicine will work better |
| Schedule of Alprostadil |
| H |
| Storage Requirements for Alprostadil |
| Patent ductus arteriosus: Store at 2 – 8 degree C in a refrigerator. Keep the medicine from freezing. Keep out of the reach of children. For erectile dysfunction: Alprostadil injection in the powder form can be stored at room temperature (15 – 25 degree C) for 3 months. After it is mixed, the solution must be used immediately. Alprostadil suppositories: Keep from freezing. They may be stored at room temperature for 14 days |
| Effects of Missed Dosage of Alprostadil |
| Do not apply |
| Effects of Overdose of Alprostadil |
| Give supportive measures and symptomatic treatment. Pyrexia and hypotension can be treated by reducing the infusion rate. |