Prostaglandin E₁ (PGE₁) is a naturally occurring

prostaglandin Prostaglandins (PG) are a group of physiology, physiologically active lipid compounds called eicosanoids that have diverse hormone-like effects in animals. Prostaglandins have been found in almost every Tissue (biology), tissue in humans and ot ...

with various medical uses. Alprostadil and

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. It is taken by mouth when used ...

are synthetic forms of prostaglandin E1 used as medications. Lubiprostone, a derivative of prostaglandin E1, is also used as a medication. Prostaglandin E₁ is a

vasodilator Vasodilation, also known as vasorelaxation, 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. Blood vessel wal ...

. It has various effects in the body that include opening

blood vessels Blood vessels are the tubular structures of a circulatory system that transport blood throughout many animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the tissues of a body. They also take waste an ...

, relaxing

smooth muscle Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non- striated, so-called bec ...

, inhibiting clotting, and causing

uterine contraction Uterine contractions are muscle contractions of the uterine smooth muscle that can occur at various intensities in both the non-pregnant and pregnant uterine state. The non-pregnant uterus undergoes small, spontaneous contractions in addition to ...

s. In infants with certain congenital heart defects, alprostadil is delivered by slow injection into a vein to maintain a

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

until surgery can be carried out. By injection into the

penis A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate. The term ''pen ...

or placement in the

urethra The urethra (: urethras or urethrae) is the tube that connects the urinary bladder to the urinary meatus, through which Placentalia, placental mammals Urination, urinate and Ejaculation, ejaculate. The external urethral sphincter is a striated ...

, alprostadil is used to treat

erectile dysfunction Erectile dysfunction (ED), also referred to as impotence, is a form of sexual dysfunction in males characterized by the persistent or recurring inability to achieve or maintain a Human penis, penile erection with sufficient rigidity and durat ...

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

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

, and low blood pressure. When injected into the penis for erectile dysfunction; side effects may include penile pain, bleeding at the site of injection, and prolonged erection (priapism). Prostaglandin E₁ was isolated in 1957 and approved for medical use in the United States in 1981. Misoprostol has various obstetric uses. It is used to induce

abortion Abortion is the early termination of a pregnancy by removal or expulsion of an embryo or fetus. Abortions that occur without intervention are known as miscarriages or "spontaneous abortions", and occur in roughly 30–40% of all pregnan ...

, to completely empty the uterus after a

miscarriage Miscarriage, also known in medical terms as a spontaneous abortion, is an end to pregnancy resulting in the loss and expulsion of an embryo or fetus from the womb before it can fetal viability, survive independently. Miscarriage before 6 weeks ...

, to induce labor, and to prevent and treat

postpartum hemorrhage Postpartum bleeding or postpartum hemorrhage (PPH) is often defined as the loss of more than 500 ml or 1,000 ml of blood following childbirth. Some have added the requirement that there also be signs or symptoms of low blood volume fo ...

. The medication is available through many routes. It can be swallowed, dissolved in the mouth, placed in the vagina, or placed in the rectum. Misoprostol can also be used to manage

duodenal ulcer Peptic ulcer disease is when the inner part of the stomach's gastric mucosa (lining of the stomach), the first part of the small intestine, or sometimes the lower esophagus, gets damaged. An ulcer in the stomach is called a gastric ulcer, while ...

s and

peptic ulcer disease Peptic ulcer disease is when the inner part of the stomach's gastric mucosa (lining of the stomach), the first part of the small intestine, or sometimes the lower esophagus, gets damaged. An ulcer in the stomach is called a gastric ulcer, while ...

when other medications are not effective. 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 s ...

for its obstetric uses. Lubiprostone is a PGE₁ derivative used to treat chronic constipation. It is taken orally. Common side effects include diarrhea, vomiting, and abdominal pain.

Biosynthesis

Prostaglandin E₁ is biosynthesized on an as-needed basis from dihomo-γ-linolenic acid (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 (PUFA) that share a final carbon-carbon double bond in the ''n''−6 position, that is, the sixth bond, counti ...

) in healthy humans without

coronary artery disease Coronary artery disease (CAD), also called coronary heart disease (CHD), or ischemic heart disease (IHD), is a type of cardiovascular disease, heart disease involving Ischemia, the reduction of blood flow to the cardiac muscle due to a build-up ...

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 chromosome abnormality. Although polygenic disorders ...

Medical uses

Alprostadil

Alprostadil is used for two main purposes: the treatment of newborns with

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

s and in treatment of

. Some babies are born with heart defects which compromise blood flow to the body. In some defects, including

tetralogy of Fallot Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, is a congenital heart defect characterized by four specific cardiac defects. Classically, the four defects are: * Pulmonary stenosis, which is narrowing of the exit from the r ...

, aortic valvular atresia, and Eisenmenger pulmonary hypertension, alprostadil is given

intravenously Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutr ...

by a nurse until surgery can be performed to repair the defect. The medication maintains a

. The ductus arteriosus is a shortcut between the aorta and pulmonary artery, two large vessels branching off the heart. This shortcut allows the

fetus A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic development, embryonic stage, the fetal stage of development takes place. Pren ...

to maintain blood flow before birth. However, it closes shortly after birth when the newborn can breathe oxygen. In babies with certain congenital defects, however, it's essential to keep the ductus arteriosus open to ensure at least some blood flow throughout the body. Side effects include decreased breathing or a lack of breathing at high doses. The medication can also cause

hypotension Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is ...

, or low blood pressure. Alprostadil is also used for adults with erectile dysfunction. It is typically given when other medications are ineffective. The medication relaxes smooth muscle and allows the arteries in the corpus cavernosum of the penis to dilate. Blood then flows to the penis. This blood flow compresses the veins which drain blood from the penis, trapping the blood in the corpus cavernosum. This process leads to erection. When injected into the base of the penis, alprostadil may cause penile pain, dizziness, headache, high blood pressure, Peyronie disease, and burning at the injection site. When inserted into the urethra, alprostadil may cause urethral burning, penile pain, dizziness, headache, and urethral bleeding. When someone engages in vaginal sex after using an alprostadil urethral suppository, their partner may experience vaginal itching. Clinical trials for the treatment showed positive results in around 3,000 men that it was tested on; it is said to be usable by men with diabetes or heart problems and those who have undergone a

prostatectomy Prostatectomy (from the Ancient Greek language, Greek , "prostate" and , "excision") is the surgical removal of all or part of the prostate gland. This operation is done for benignity, benign conditions that cause urinary retention, as well as ...

Misoprostol

Misoprostol has a variety of uses in

obstetrics and gynecology Obstetrics and gynaecology (also spelled as obstetrics and gynecology; abbreviated as Obst and Gynae, O&G, OB-GYN and OB/GYN) is the medical specialty that encompasses the two subspecialties of obstetrics (covering pregnancy, childbirth, and t ...

. It is also used to relieve pain from duodenal ulcers when other treatments have been ineffective. Misoprostol can be used to induce labor in patients at the end of pregnancy. It causes cervical ripening, or the thinning and shortening of the

cervix The cervix (: cervices) or cervix uteri is a dynamic fibromuscular sexual organ of the female reproductive system that connects the vagina with the uterine cavity. The human female cervix has been documented anatomically since at least the time ...

in preparation for birth. It also causes uterine contractions, allowing the body to expel the baby. For this purpose, it is placed inside the vagina. Misoprostol is also used to prevent and treat postpartum hemorrhage (PPH), or uncontrolled bleeding following childbirth. The

World Health Organization The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...

estimates that PPH causes 70,000 maternal deaths each year. Misoprostol induces uterine contractions, encouraging the uterus to shrink after childbirth. This shrinking puts pressure on blood vessels on the uterus, forcing them to close rather than continue to bleed. To prevent PPH, misoprostol is given orally or dissolved under the tongue immediately after delivery. To treat PPH, it is given orally, dissolved under the tongue, or placed in the rectum. For the management of miscarriage in the first trimester of pregnancy, misoprostol is used to completely empty the uterus. This is important because the patient may develop an infection if they retain the products of conception. Misoprostol causes uterine contractions, forcing the body to expel the pregnancy. It can be used alone, but it is more effective in conjunction with

mifepristone Mifepristone, and also known by its developmental code name RU-486, is a drug typically used in combination with misoprostol to bring about a medical abortion during pregnancy. This combination is 97% effective during the first 63 days (9 wee ...

. Misoprostol is swallowed, placed inside the vagina, or dissolved in the mouth for this purpose. Misoprostol can also be used to induce termination of pregnancy. It can be used on its own or following administration of mifepristone. Misoprostol may be used to terminate a pregnancy; typically only in the first trimester. Later abortions are less common and are usually performed surgically, at least in the United States. For first-trimester abortion, it is dissolved in the cheek or under the tongue; for later abortions, it can also be given as a vaginal suppository. Misoprostol may also be used to ripen the cervix in preparation for surgical abortion. Misoprostol is given orally for the treatment of ulcers. It interacts with prostaglandin receptors in the stomach to reduce secretion of stomach acids. It increases the production of gastric mucus, which forms a protective coating against stomach acid. Finally, misoprostol encourages the production of

bicarbonate In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial bioche ...

, which is a base that counteracts stomach acid. The medication can also protect against stomach ulcers in people who take NSAIDs such as

ibuprofen Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that is used to relieve pain, fever, and inflammation. This includes dysmenorrhea, painful menstrual periods, migraines, and rheumatoid arthritis. It can be taken oral administration, ...

on a daily basis. Misoprostol can cause nausea, stomach pain, and stomach cramps. In rare cases, it may lead to uterine rupture, which requires immediate emergency surgery.

Other uses

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. Preventative administration of alprostadil may reduce the risk of kidney injury (specifically contrast-induced nephropathy) in persons having cardiac angiography or percutaneous coronary intervention. Lubiprostone is a PGE₁ derivative used to treat chronic constipation. It is taken orally. Common side effects include diarrhea, vomiting, and abdominal pain.

References

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