Prostaglandins: Uses, common brands, and safety info

Prostaglandin analogues are a class of drugs that mimic the function of naturally occurring prostaglandins that are hormones derived from phospholipids in the body. When prostaglandins bind to prostaglandin receptors on the cell surface, they affect different biological processes. For example, prostaglandin biosynthesis plays a role in pain and inflammation, controlling eye pressure, stomach acid production, and inducing labor during pregnancy. Because prostaglandins have many different functions in the body, synthetic prostaglandins are also used for a wide variety of diseases. The most common treatment is for glaucoma, but prostaglandin analogues can also treat stomach ulcers, erectile dysfunction, pulmonary hypertension, and induce labor.

Let’s take a look at prostaglandins to better understand their uses, side effects, and safety information. The table below lists commonly used prostaglandin drugs and their costs. 

Other prostaglandins

• Prepidil (dinoprostone)

• Veletri (epoprostenol)

• Flolan (epoprostenol)

• Remodulin (treprostinil)

• Tyvaso (treprostinil)

• Orenitram (treprostinil)

• Ventavis (iloprost)

What are prostaglandins?

Prostaglandins are lipid compounds with hormone-like effects in the body and are vital to the healing process. Upon signs of injury or illness, cells begin producing prostaglandins from arachidonic acid, a fatty acid that’s present in the cell membrane. An enzyme named cyclooxygenase (COX) then activates arachidonic acid to begin prostaglandin production. The two types of COX enzymes, COX-1 and COX-2, both work to increase prostaglandin synthesis. This results in inflammation, blood clotting, and other important biological processes. When your body doesn’t make enough natural prostaglandins, manufactured prostaglandin drugs can increase their levels and treat a number of conditions.

How do prostaglandins work?

The production of prostaglandins occurs locally, and prostaglandins only act in areas surrounding where they are released and are quickly cleared afterward. Because they are found in almost every organ, prostaglandins act as diverse regulators of the endocrinology and function of the body.

Some major functions of prostaglandins include:

• Controlling pain, redness, and swelling to promote healing during the inflammatory response

• Regulating immune cells (macrophages and leukocytes)

• Vasoconstriction or vasodilation (constriction or relaxing of blood vessels)

• Inhibition of gastrointestinal acid secretion

• Reducing pressure in the eye

• Regulating menstruation, including ovulation and menstrual cramps

• Inducing labor during pregnancy

Prostaglandin analogues are medications that resemble these natural chemicals. They work by targeting one of the specific functions mentioned above to help treat different diseases.

What are prostaglandins used for?

Glaucoma

One of the main reasons for using prostaglandins is to treat patients with glaucoma. In glaucoma, drainage canals in the eye slowly become clogged, causing increased eye pressure from the buildup of extra fluid. Without treatment, glaucoma eventually causes blindness. 

Prostaglandin eye drops are common treatments for glaucoma because they promote fluid outflow from the eye and reduce high eye pressure. One interesting side effect of prostaglandin eye drops is that they increase hair growth, and the medication Latisse (bimatoprost) is used specifically to grow eyelashes. In a clinical trial of 278 adults using Latisse for four months, 78% of patients saw an increase in eyelash growth.

Stomach ulcers

Another way prostaglandins work is to protect the stomach lining from too much acid. For example, the prostaglandin drug Cytotec (misoprostol) causes inhibition of acid secretion and protects the stomach from damage in patients with stomach ulcers. 

Blood flow

In other parts of the body, the role of prostaglandins is to help open blood vessels. In erectile dysfunction, they work by increasing vascular blood flow to help maintain an erection. When targeting the lungs, they also work in a similar way to reduce high blood pressure and improve cardiovascular ability. 

Labor induction

Finally, in women, prostaglandins have a major role during pregnancy. They help relax the smooth muscles in the uterus, causing the cervix to dilate. In this way, prostaglandin drugs may be used during labor and delivery.

Types of prostaglandins 

Prostaglandin F 2α

Prostaglandin F 2α (PGF 2α) drugs primarily have an effect on the eye. “F2 alpha” is named after the type of G protein-coupled receptor that the medication binds to when entering the cell. Prostaglandins in this category move fluid out of the eye to reduce high eye pressure, making them important treatments for glaucoma. 

Examples of prostaglandin F 2α analogues:

• Xalatan (latanoprost) 

• Zioptan (tafluprost)

• Travatan Z (travoprost)

• Lumigan (bimatoprost) 

• Vyzulta (latanoprostene bunod) 

Prostaglandin E1

Prostaglandin E1 (PGE 1) is also known as alprostadil. It is most effective for treating erectile dysfunction by opening blood vessels to increase vascular blood flow. Alprostadil is available as an injection or as pellets that are inserted into the urethra. Misoprostol is another prostaglandin E1 drug that works as an inhibitor of acid production in the stomach, and it’s used to prevent stomach ulcers in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen.

Examples of prostaglandin E1 analogues:

• Muse (alprostadil) 

• Edex (alprostadil)

• Caverject (alprostadil)

• Caverject Impulse (alprostadil)

• Cytotec (misoprostol) 

Prostaglandin E2 

Prostaglandin E2 (PGE 2), also known as dinoprostone, increases uterine contractions, opens blood vessels, and prepares the cervix for labor and delivery during pregnancy. The PGE 2 medication Cervidil is available as a vaginal insert and is approved by the Food and Drug Administration (FDA) for use in pregnant women who are near their delivery due date.

Examples of prostaglandin E2 analogues:

• Cervidil (dinoprostone)

• Prepidil (dinoprostone)

Prostacyclins

Prostacyclins (also called prostaglandin I2 or PGI 2) are specific types of prostaglandins that have an important role in respiratory diseases. In healthy people, prostacyclins relax blood vessel walls and allow blood to flow freely in the lungs. People with pulmonary arterial hypertension don’t make enough natural prostacyclin, causing narrowing of blood vessels and high blood pressure in the lungs. Prostacyclin drugs are an important treatment for this disease.

Examples of prostacyclin analogues:

• Veletri (epoprostenol)

• Flolan (epoprostenol)

• Remodulin (treprostinil)

• Tyvaso (treprostinil)

• Ventavis (iloprost)

Who can take prostaglandins?

Men

Men with erectile dysfunction may take certain prostaglandins as a second-line therapy if they cannot tolerate or use oral medications to treat the condition.

Women

Prostaglandin therapy can be used in pregnant women to induce labor and delivery. The medication is given at a hospital or clinic unless otherwise directed by a healthcare provider.

Seniors

Adults older than 60 are at a higher risk of developing glaucoma, and prostaglandin eye drops are the first line of treatment for this disease. Because glaucoma is a progressive disease that leads to vision loss if untreated, it is especially important that seniors with glaucoma maintain drug therapy and complete regular eye exams. Older patients who take NSAIDs regularly are also at a higher risk of developing stomach ulcers and may be given prostaglandin therapy as prevention.

Children

Children may take prostaglandins for rare conditions such as childhood glaucoma and pediatric pulmonary hypertension. Prostaglandin E1 is also approved for use in newborn babies with congenital heart defects. 

Are prostaglandins safe?

As natural chemicals in the body, prostaglandin drugs are generally safe with proper use. The side effects depend on the type of treatment and how the medication is taken. 

Recalls

In 2015, the manufacturer discontinued Rescula (unoprostone)—a glaucoma drug—in the U.S., but it was not withdrawn for safety or efficacy reasons. Other recalls can be found in the FDA drug recall database.

Restrictions

Certain prostaglandins such as Cytotec (misoprostol) have a black box warning because they pose a safety risk for pregnant women and may cause premature birth. This medication is restricted in pregnant women, and women who may become pregnant must take certain precautions, such as using effective contraception or having a negative pregnancy test before starting therapy. 

Do not use prostaglandins for erectile dysfunction if you have the following conditions that increase the risk of a prolonged erection:

• Sickle cell anemia

• Blood cancers like multiple myeloma, leukemia, or polycythemia vera

• Thrombocytosis (increased number of platelets)

Patients with glaucoma should not administer prostaglandin eye drops while wearing contact lenses. Remove contact lenses before use and then reinsert at least 15 minutes after putting in the eye drops.

Patients with heart failure should avoid certain prostacyclins and patients with liver problems should use them with caution.

For all indications, do not take prostaglandins if you have any type of sensitivity to the drug.

Are prostaglandins controlled substances?

No, prostaglandins are not controlled substances. 

Common prostaglandins side effects

Side effects differ depending on the product and administration. Some side effects may be local and only appear in the area where the drug is used, while other reactions affect larger areas of the body. Speak to your healthcare provider about specific side effects and risks you might experience while taking these medications. 

Common side effects of prostaglandins include:

• Darkening of eye color

• Increased eyelash growth

• Redness, Itching, or burning near the eye

• Blurry vision

• Feeling as if something is in the eye

• Increased sensitivity to light

• Penile pain

• Prolonged erection

• Diarrhea

• Stomach pain 

• Nausea

Serious side effects of prostaglandins include:

• Macular edema (swelling in the retina of the eye)

• Keratitis (inflammation of the cornea of the eye)

• Penile fibrosis (scarring)

• Penile hematoma (bleeding or bruising)

• Severe diarrhea

• Heavy and painful periods

If you experience an allergic reaction and have symptoms of difficulty breathing, swelling of the throat or tongue, hives, or rash, seek medical attention right away.

How much do prostaglandins cost?

The cost of prostaglandin drugs varies depending on the type of formulation, the strength, and whether the drug is a brand name or generic version. Prices range from $87 to $600, and may also differ based on your insurance coverage. Typically, prostaglandin drugs for glaucoma can be expensive, but SingleCare offers coupons to help lower the price. Speak with your healthcare provider and insurance company or use a free prescription discount card from SingleCare to find the best choice for you.