Medication is considered the foundation of treatment for ulcerative colitis.

Your doctor will recommend one or more drugs depending on how severe the disease is, as well as your overall health and other factors, according to the Crohn’s and Colitis Foundation.

At first, the goal of treatment with medication will be to reduce the severity and frequency of your symptoms.

Medications may be given short term at first to quickly achieve this. But during this time, your gastroenterologist will be starting or planning to start you on subsequent medications to safely keep you in remission.

There are five main classes of drugs used to treat ulcerative colitis.

1. Aminosalicylates

This group of medications contains a chemical compound called 5-aminosalicylate acid. It includes the following drugs:

Mesalamine is typically one of the first drugs prescribed for mild to moderate ulcerative colitis.

Mesalamine is used both to treat active symptoms of ulcerative colitis and as a maintenance drug to prevent symptoms from recurring.

Mesalamine and other aminosalicylates may be taken orally as a tablet or capsule, or rectally, as a suppository or in an enema. Depending on the formulation, it may be necessary to take three or four doses of the drug daily.

For ulcerative proctitis — when the disease is confined to your rectum — your doctor may prescribe the suppository formulation alone.

For ulcerative colitis that extends beyond your rectum, your doctor may prescribe a suppository or enema as well as an oral formulation, Mayo Clinic notes.

Past research has suggested that as many as 80 percent of people with ulcerative colitis respond to oral aminosalicylates within four weeks.

Common side effects of mesalamine include headache, nausea, fever, and rash. The same side effects are common in sulfasalazine, and can sometimes be worse than side effects with mesalamine. Another side effect of sulfasalazine is infertility in men, which usually resolves when the medication is stopped.

2. Corticosteroids

These medicines, also known simply as steroids, are typically used to treat flares of ulcerative colitis.

Steroids may be taken orally or rectally, and include the following drugs:

Budesonide is considered a first-line treatment for ulcerative colitis. It can be taken orally as a tablet or capsule, or rectally, as a foam or tablet or in an enema. Because of the way the body processes budesonide, the oral form causes fewer side effects than other corticosteroids, according to research.

Prednisone, hydrocortisone, and methylprednisolone work by suppressing the entire immune system, rather than targeting specific inflammatory pathways.

Because of their high risk of side effects, these three drugs are typically reserved for moderate to severe ulcerative colitis. They also shouldn’t be taken for very long.

If you take corticosteroids orally or by injection, you may have significant side effects. Local steroids — which are applied just to the area that needs treatment — are generally the preferred option.

For severe flares of ulcerative colitis, hospitalization and high-dose intravenous (IV) corticosteroids are often required. Once remission is achieved, your dose of steroids will be tapered gradually and, ideally, eventually stopped. Steroids can’t be stopped suddenly, because they cause the body to reduce its production of the natural steroid cortisol.

Steroids are ineffective as maintenance therapy to keep ulcerative colitis in remission.

Once you start taking steroids, you and your doctor should start talking about other, safer medications that may help bring this disease under control.

According to Mayo Clinic, possible side effects of steroids include:

Infection
Weight gain
High blood sugar
Mood, memory, or behavioral problems
Acne
Increased hair growth on the body and face
High blood pressure
Osteoporosis

3. Immunomodulators

Also known as immunosuppressants, these drugs work by limiting inflammation at its source in the immune system.

They’re usually reserved for cases in which aminosalicylates or, possibly, biologics haven’t been effective enough. They may reduce or eliminate the need for corticosteroids.

Immunomodulators may take several months to start working. They include the following drugs:

Because immunomodulators modify the activity of the immune system, there is an increased risk of developing an infection in sites like the liver.

Before you begin a course of treatment using an immunomodulator, it’s important to have a recent complete blood count (CBC) and continue periodic monitoring of your blood levels and chemistry while taking the drug.

Like corticosteroids and biologics, immunomodulators raise the risk of infection.

4. Biologics

Biologics act against a protein that’s part of your immune system response. Some biologics are also tumor necrosis factor (TNF) inhibitors.

They’re reserved for moderate to severe cases of ulcerative colitis that don’t respond well to other treatments.

Biologics include the following drugs:

Like certain other drugs for ulcerative colitis, biologics can increase your risk of infection. But if one of these drugs is controlling your ulcerative colitis symptoms without bothersome side effects, the benefits of continuing the drug often outweigh its risks.

5. Small Molecules

Small molecules are oral medications that also work on the immune system, but act differently from biologics.

Janus kinase (JAK) inhibitors like tofacitinib (Xeljanz) and upadacitinib (Rinvoq) suppress the immune system by blocking the JAK enzyme, thereby preventing it from activating specific cells that cause inflammation.

These drugs are used to treat moderate to severe ulcerative colitis.

There is an increased risk of serious heart-related events such as heart attack and stroke, cancer, blood clots, and death with tofacitinib (Xeljanz).

Ozanimod (Zeposia) is an oral small molecule medication taken once daily for adults with moderately to severely active ulcerative colitis. It’s the first in a class of drugs known as sphingosine 1-phosphate receptor modulators.

The exact way Zeposia works is unknown, but the drug is thought to act on lymphocytes, which are immune cells responsible for causing inflammation in the intestines. The drug binds to receptors on the surface of the cells, helping prevent them from moving into the colon and causing damaging inflammation.

Other Medication

Your doctor may prescribe or recommend these other drugs and supplements to help treat ulcerative colitis.

Antidiarrheal medicines While these drugs can help control diarrhea, they can also slow down your digestive function and increase your risk of toxic colitis, a severe complication. Because of these risks, antidiarrheal drugs should be used only under strict medical supervision.

Pain relievers Your doctor may recommend acetaminophen (Tylenol) for mild pain. Avoid ibuprofen (Advil or Motrin), naproxen (Aleve), and diclofenac (Voltaren), which can cause digestive upset and worsen ulcerative colitis symptoms.

Iron supplements These supplements may be needed if you have chronic intestinal bleeding that results in a deficiency.

Additional reporting by Ashley Welch.