Giant cell arteritis (GCA) inflames the arteries. Along with symptoms like headaches, jaw pain, and fatigue, it can cause blindness and other serious complications if it’s not treated.

Treatment with steroid medications is the main way to stop inflammation of GCA and prevent complications. You may have to stay on these medications for a couple of years, and they can have side effects, but these can be managed.

The search is still on for new treatments that help with this vision threatening disease but cause fewer side effects.

As of now, there is no immediate cure for GCA. Treatment with high-dose steroids can stop symptoms quickly, in as few as 1 to 3 days. Many people go into remission on these drugs, meaning they have no signs of the disease, and do not progress to vision loss.

Taking medication right away can prevent damage caused by inflamed blood vessels. Early treatment can help you avoid vision loss, stroke, and other serious complications of GCA.

In 2017, the FDA approved the first treatment specifically for GCA. Tocilizumab (Actemra) is a type of biologic drug called a monoclonal antibody. It targets the immune system to bring down inflammation.

Doctors prescribe Actemra for people whose symptoms haven’t improved on steroid drugs, or who can’t take steroids because of the side effects. In studies, Actemra helped people with GCA stay in remission long-term.

However, the relapse rate may be higher compared to steroid treatment alone. More studies are needed to determine the best course of therapy.

Actemra comes as an injection you get under your skin once a week or every other week. Some people keep taking steroids along with Actemra, but they’re able to take a lower steroid dose.

The most common side effects of Actemra are:

  • reactions at the site of injection
  • colds and other respiratory tract infections
  • headaches
  • increased blood pressure
  • abnormal liver function test results

Because Actemra affects your immune system, it can increase your risk of serious and unusual infections. If you’re considering taking this drug, talk to your doctor about the possible side effects and benefits.

Given the serious side effects linked to high-dose steroid treatment, the hunt is on for other medications that treat GCA. A few other biologic drugs are under investigation. These medications target specific proteins and other substances that contribute to inflammation.

So far, none of these drugs have been approved by the FDA, but a few of them have shown promise in studies.

Abatacept. This biologic drug blocks communication between immune cells called T cells that cause inflammation. In one small study, abatacept combined with steroid drugs slightly reduced the risk of relapse in people with GCA.

Azathioprine. This immune-suppressing drug is used to treat rheumatoid arthritis, lupus, and multiple sclerosis. It may have potential as an alternative to high-dose steroids in GCA. Azathioprine may also help people who have side effects from steroids to lower their dose.

People who take azathioprine will need to be monitored carefully. This medication can cause side effects like vomiting, diarrhea, hair loss, and sensitivity to sunlight.

Leflunomide. This immune-suppressing drug treats rheumatoid arthritis and psoriatic arthritis. In one small study, people with GCA were less likely to relapse while taking a combination of leflunomide and steroids than on steroids alone. Leflunomide helped more than half of people who took it wean off of steroids.

Ustekinumab. This monoclonal antibody is approved to treat psoriasis and psoriatic arthritis. It works by blocking the activity of inflammatory substances interleukin-12 (IL-12) and IL-23. In one small study of GCA, it helped about a quarter of people who took it taper off of their steroid drugs completely.

Cyclophosphamide. This older chemotherapy drug also suppresses the immune system. It may be a useful treatment for people with GCA who’ve had side effects from steroids, who’ve been taking steroids for a long time, or who have very aggressive disease.

TNF inhibitors. This group of biologic drugs reduces inflammation in the body. TNF inhibitors are used to treat rheumatoid arthritis, psoriatic arthritis, and other autoimmune diseases. So far, these drugs don’t seem to work for GCA.

Anakinra. This medication targets the inflammatory protein IL-1. It has helped some people whose GCA didn’t improve with other treatments. Anakinra is still under investigation.

Corticosteroid drugs like prednisone have been around since the 1950s, and they remain the main treatment for GCA today. As soon as your doctor suspects you have GCA, you should start taking high-dose steroid pills at 40 to 60 milligrams (mg).

If you’ve already lost vision, you may get even higher doses of a steroid drug delivered through an IV into a vein. Once your symptoms are stable, you’ll change over to a steroid pill.

Steroid drugs work quickly. Symptoms usually start to improve within a couple of days.

You’ll stay on the high-dose steroid for up to 4 weeks. Then your doctor will start to gradually lower the dose if your symptoms are under control.

Your doctor will monitor your symptoms and measure levels of inflammatory markers in your blood to determine what dose you need. Dropping the dose too quickly could cause a return of your symptoms, called a relapse.

You may have to stay on a steroid drug for up to 2 years to keep GCA under control. Long-term use of these drugs can cause side effects. The most common ones are:

  • cataracts
  • bone fractures
  • infections
  • high blood pressure
  • high blood sugar
  • weight gain

See your doctor if you develop any of these side effects. You may need medication to treat them. For example, bisphosphonate drugs strengthen bones and prevent fractures.

Methotrexate is another drug your doctor might prescribe if a steroid drug isn’t helping enough, or it causes side effects that you can’t tolerate. Methotrexate treats cancer, rheumatoid arthritis, and other autoimmune diseases. In GCA, it suppresses your immune system to bring down inflammation in your arteries.

When you start taking methotrexate, you may be able to lower your dose of steroids. Methotrexate may also help you stay in remission and avoid relapses of your symptoms.

GCA isn’t curable, but long-term treatment with steroid medications can put you into remission. If this treatment doesn’t work, or it causes side effects that you can’t tolerate, your doctor might also give you methotrexate or Actemra.

Researchers are studying several other drugs for GCA. The hunt is on for treatments that work as well as or better than steroids, but with fewer side effects.