Prostaglandin E1 (PGE1), also known as alprostadil, is a naturally occurring

prostaglandin The prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids having diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals. They are derive ...

which is used as a medication. In infants with

congenital heart defects A congenital heart defect (CHD), also known as a congenital heart anomaly and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital heart defect is classed as a cardiovascular ...

, it is delivered by slow injection into a vein to open the

ductus arteriosus The ''ductus arteriosus'', also called the ''ductus Botalli'', named after the Italian physiologist Leonardo Botallo, is a blood vessel in the developing fetus connecting the trunk of the pulmonary artery to the proximal descending aorta. It a ...

until surgery can be carried out. By injection into the

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do n ...

or placement in the

urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra con ...

, it is used to treat

erectile dysfunction Erectile dysfunction (ED), also called impotence, is the type of sexual dysfunction in which the penis fails to become or stay erect during sexual activity. It is the most common sexual problem in men.Cunningham GR, Rosen RC. Overview of male ...

. Common side effects when given to babies include decreased breathing,

fever Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...

, and

low blood pressure Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the dia ...

. When used for erectile dysfunction side effects may include penile pain, bleeding at the site of injection, and prolonged erection (priapism). Prostaglandin E1 is in the

vasodilator Vasodilation is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstriction, ...

family of medications. It works by opening

blood vessels The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away f ...

and relaxing

smooth muscle Smooth muscle is an involuntary non-striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit mus ...

. Prostaglandin E1 was isolated in 1957 and approved for medical use in the United States in 1981. It is on the

World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health ...

Medical uses

Patent ductus arteriosus

Alprostadil is also used in maintaining a

patent ductus arteriosus ''Patent ductus arteriosus'' (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs by flowing from the aorta, which has ...

newborn An infant or baby is the very young offspring of human beings. ''Infant'' (from the Latin word ''infans'', meaning 'unable to speak' or 'speechless') is a formal or specialised synonym for the common term ''baby''. The terms may also be used to ...

s. This is primarily useful when the threat of premature closure of the ductus arteriosus exists in an infant with ductal-dependent congenital heart disease, including cyanotic lesions (e.g., hypoplastic left heart syndrome, pulmonary atresia/stenosis, tricuspid atresia/stenosis, transposition of the great arteries) and acyanotic lesions (e.g., coarctation of the aorta, critical aortic stenosis, and interrupted aortic arch).

Sexual dysfunction

Alprostadil is sold in the United States as

urethral suppositories A suppository is a dosage form used to deliver medications by insertion into a body orifice where it dissolves or melts to exert local or systemic effects. There are three types of suppositories, each to insert into a different sections: rectal s ...

and in injectable form. The suppositories are sold under the brand name Muse. The injectable forms are Edex and Caverject. Muse delivers alprostadil as a penile suppository, inserted into the urethra, at least ten minutes before the erection is needed. Caverject and Edex are similarly fast-acting, but instead are injected by syringe directly into the corpus cavernosum of the penis. Alprostadil is also available as a generic. The major cost is that it must be mixed by a

compounding pharmacy In the field of pharmacy, compounding (performed in compounding pharmacies) is preparation of a custom formulation of a medication to fit a unique need of a patient that cannot be met with commercially available products. This may be done for me ...

and supplies may be difficult to obtain. The different formulations, including Bimix and Trimix, may include

papaverine Papaverine (Latin ''papaver'', "poppy") is an opium alkaloid antispasmodic drug, used primarily in the treatment of visceral spasms and vasospasms (especially those involving the intestines, heart, or brain), occasionally in the treatment of erec ...

and/or

phentolamine Phentolamine, sold under the brand name Regitine among others, is a reversible nonselective α- adrenergic antagonist. Mechanism Its primary action is vasodilation due to α1 blockade. Non-selective α-blockers can cause a much more pronounced ...

. A typical mix might be 30 mg of papaverine, 2 mg of phentolamine, and 20 μg alprostadil. As a generic, it is much less expensive than the packaged injectables. It is premixed and must be kept refrigerated and the user must load a syringe with the quantity needed.Most recently, the compound has been made easily accessible in an applicable topical cream form known as Vitaros. Made by Takeda UK Ltd, it is now available in Europe and contains either 200 or 300 micrograms of alprostadil in 100 mg of cream which is directly administered as a topical cream applied to the urethra in a preloaded delivery device. The tip of the device is placed in the urethral meatus and the cream delivered into the urethra. Clinical trials for the treatment showed positive results in over 3000 men that it was tested on, and unlike other sexual dysfunction medication, it is said to be usable by men with diabetes or heart problems and those who have undergone a prostatectomy. It has no known interactions with food, alcohol or other medications making it safer than other treatments containing alprostadil. Similarly to the Bimix and Trimix injections though, it must be kept under cool temperatures.

Critical limb ischemia

Prostanoids, including alprostadil, do not reduce the risk of limb amputation but may offer a slight improvement in rest-pain and leg ulcer healing in persons with critical limb ischemia.

Contrast-induced nephropathy

Preventative administration of alprostadil may reduce the risk of kidney injury (specifically contrast-induced nephropathy) in persons having cardiac angiography or percutaneous coronary intervention.

Adverse effects

* Accidental injury (Muse only) *

Apnea Apnea, BrE: apnoea, is the temporal cessation of breathing. During apnea, there is no movement of the muscles of inhalation, and the volume of the lungs initially remains unchanged. Depending on how blocked the airways are ( patency), there ...

* Bleeding: ** Cerebral ** Urethral *

Bradycardia Bradycardia (also sinus bradycardia) is a slow resting heart rate, commonly under 60 beats per minute (BPM) as determined by an electrocardiogram. It is considered to be a normal heart rate during sleep, in young and healthy or elderly adults, a ...

* Cardiac arrest *

Congestive heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...

* Cortical proliferation of long bones * Diarrhea * Disseminated intravascular coagulation * Edema * Fever * Flushing * Hyperemia *

Hypotension Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the dias ...

* Injection-site haematoma * Injection-site ecchymosis (Caverject only) * Pain: ** Back ** Pelvic ** Penile ** Testicular (Muse only) ** Urethral * Prolonged erection * Penile fibrosis * Second-degree heart block *

Seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

s * Sepsis * Shock * Spasm of right ventricle infundibulum *

Supraventricular tachycardia Supraventricular tachycardia (SVT) is an umbrella term for fast heart rhythms arising from the upper part of the heart. This is in contrast to the other group of fast heart rhythms – ventricular tachycardia, which start within the lower cham ...

Tachycardia Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal (su ...

Ventricular fibrillation Ventricular fibrillation (V-fib or VF) is an abnormal heart rhythm in which the ventricles of the heart quiver. It is due to disorganized electrical activity. Ventricular fibrillation results in cardiac arrest with loss of consciousness and no p ...

* Urethral burning * Uterine rupture

Biosynthesis

Prostaglandin E1 is biosynthesized on an as-needed basis from

dihomo-γ-linolenic acid Dihomo-γ-linolenic acid (DGLA) is a 20-carbon ω−6 fatty acid. (also called, cis,cis,cis-8,11,14-Eicosatrienoic acid) In physiological literature, it is given the name 20:3 (ω−6). DGLA is a carboxylic acid with a 20-carbon chain and thr ...

(an

omega-6 fatty acid Omega-6 fatty acids (also referred to as ω-6 fatty acids or ''n''-6 fatty acids) are a family of polyunsaturated fatty acids that have in common a final carbon-carbon double bond in the ''n''-6 position, that is, the sixth bond, counting from ...

) in healthy humans without

coronary artery disease Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pla ...

and/or a

genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders ...

Other versions

Misoprostol Misoprostol is a synthetic prostaglandin medication used to prevent and treat stomach and duodenal ulcers, induce labor, cause an abortion, and treat postpartum bleeding due to poor contraction of the uterus. Misoprostol is taken by mouth wh ...

is another synthetic prostaglandin E₁ analog used to prevent gastric ulcers when taken on a continuous basis, to treat missed miscarriage, to induce labor, and to induce abortion.

References

External links

* {{portal bar, Medicine Alkene derivatives Carboxylic acids Cyclopentanes Erectile dysfunction drugs Ketones Prostaglandins Secondary alcohols World Health Organization essential medicines Wikipedia medicine articles ready to translate