Overview of Prostaglandin E1 (Alprostadil) Injection
Dosage Strengths of Prostaglandin E1 (Alprostadil) Injection
100 mcg/Vial. Lyophilized.
A potent hormone-like substance that induces erection by relaxing the penis's blood vessels and dilating cavernosal arteries-dilation of the cavernosal arteries is accompanied by increased arterial inflow velocity and increased venous outflow resistance allowing for more blood into the penis and less blood out.
Prostaglandin E1 is administered intracavernosally. This drug is prescribed as a second-line treatment, after oral PDE5 inhibitors have been ineffective for treatment of erectile dysfunction.1 Several aspects of its effects and clinical use have been reviewed previously.23 Currently the body of medical literature demonstrates that 40 to 70% of erectile dysfunction patients respond to treatment with prostaglandin E1. The failure to respond to prostaglandin E1 has not been established. The demonstration that prostaglandin E1 with S-nitrosoglutathione in combination is more effective than prostaglandin E1 alone may shed light on the lack of efficacy in some patients.4
Medications to activate alternative relaxant pathways in addition to by prostaglandin E1 may be necessary in patients who fail to respond to prostaglandin E1. Relaxation of smooth muscle is a critical component of erectile capacity. Additional agents to work in combination with prostaglandin E1 might have significant therapeutic benefits. Prostaglandin E1 with S-nitrosoglutathione or other erectile dysfunction medications, might have advantages in the treatment of male erectile dysfunction. Empower Pharmacy strives to compound medications that take advantage of multi-compound synergy. When injected into penile tissue prostaglandin E1 is readily metabolized into other erectile promoting molecules. These molecules potentiate the efficacy of prostaglandin E1. Prostaglandin E1 has been demonstrated to alter the concentrations of noradrenalin,5 adding a secondary mechanism of action. However, it is still believed prostaglandin E1 primarily acts directly by increasing cAMP synthesis via EP receptor interaction, increasing muscular relaxation.6
Prostaglandin E1 has ubiquitous actions in controlling processes in many tissues. Known effects of prostaglandin E1 include systemic vasodilation, prevention of platelet aggregation, and ask to stimulate intestinal activity. Thus, prostaglandin E1 has very rarely been administered in a fashion to elicit a systemic response. Pharmacokinetics data is currently lacking on prostaglandin E1, the current data suggest short action duration and high rate of metabolic breakdown. After the first pass through the lungs 70% is metabolized.7 Because prostaglandin E1 is readily metabolized throughout the body, penile injection effects mainly penile tissues. Furthermore, this further explains the rare circulatory side effects.
Reasons Not to Take This Medicine
- Do not take this medicine with any of the following medications: hypersensitivity or allergy to any component of this formulation; conditions predisposing you to priapism (painful erection lasting 4 hours or more): sickle cell anemia, multiple myeloma or leukemia; anatomical deformation of the penis or penile implants; direction by your physician that sexual activity is inadvisable or contraindicated
Ideally, the injection should be administered just prior to foreplay. It is administered via intracavernosal injection and should produce an erection in 5 to 20 minutes and can be expected to last up to one hour. To prevent bruising, apply firm pressure to the injection site for 5 minutes after injecting. Do not use Alprostadil Injection more than two times a week; use at least 24 hours apart. There is a possibility of needle breakage with use of Alprostadil Injection: you should pay careful attention to your doctor's instructions and handle syringe and needle properly.
Adverse Reactions/Side Effects
Mild to moderate pain during injection; painful sensation with erection; small amount of bleeding at the injection site. Call your healthcare provider if you notice any redness, lumps, swelling, tenderness or curvature of the erect penis. If you experience an erection lasting more than 2 hours, you may take 2 - 4 pseudoephedrine 30 mg by mouth once and apply an ice pack.8 If your erection does not go away within the next hour, seek professional help immediately. Erections that last more than 6 hours can cause serious damage to penile tissue.
Store dry powder at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Once reconstituted keep this medicine in a refrigerator between 36°F to 46°F (2°C to 8°C). Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond use date. Do not flush unused medications or pour down a sink or drain.
- 1. Albersen, M., et al., Evaluation and treatment of erectile dysfunction. Med Clin North Am, 2011. 95(1): p. 201-12.
- 2. Linet, O.I. and F.G. Ogrinc, Efficacy and safety of intracavernosal alprostadil in men with erectile dysfunction. The Alprostadil Study Group. N Engl J Med, 1996. 334(14): p. 873-7.
- 3. Porst, H., The rationale for prostaglandin E1 in erectile failure: a survey of worldwide experience. J Urol, 1996. 155(3): p. 802-15.
- 4. Angulo, J., et al., Rationale for the combination of PGE(1) and S-nitroso-glutathione to induce relaxation of human penile smooth muscle. J Pharmacol Exp Ther, 2000. 295(2): p. 586-93.
- 5. Molderings, G.J., et al., Inhibition of noradrenaline release from the sympathetic nerves of the human saphenous vein by presynaptic histamine H3 receptors. Naunyn Schmiedebergs Arch Pharmacol, 1992. 346(1): p. 46-50.
- 6. Palmer, L.S., et al., Characterization of cyclic AMP accumulation in cultured human corpus cavernosum smooth muscle cells. J Urol, 1994. 152(4): p. 1308-14.
- 7. Golub, M., et al., Metabolism of prostaglandins A1 and E1 in man. J Clin Invest, 1975. 56(6): p. 1404-10.
- 8. Kirkeby, H.J., et al., [Infusion cavernosography and erectile dysfunction]. Ugeskr Laeger, 1990. 152(24): p. 1724-6.