Common Medicines Could Affect Immunotherapy Response

You might not think to tell your oncologist you popped a Tylenol for your headache yesterday or take an antihistamine to manage your seasonal allergies. But researchers at Duke University warn that if you’re being treated with cancer immunotherapy, you should.

Immunotherapy medicines for breast cancer include immune checkpoint inhibitors, like Keytruda (chemical name: pembrolizumab) and Jemperli (chemical name: dostarlimab-gxly), as well as certain monoclonal antibodies, including Enhertu (chemical name: fam-trastuzumab-deruxtecan-nxki) and Herceptin (chemical name: trastuzumab). These medicines guide your body’s immune system to recognize and attack cancer cells.

In a commentary published in the Journal of Clinical Oncology, the researchers reviewed dozens of studies on how common over-the-counter and prescription drugs affect the immune system or interact with immunotherapy.

In some cases, popular medicines seemed to change how people responded to immunotherapy and were linked to lower cancer survival rates.

“Some of these drugs might not only make immunotherapy less effective, but they could also be causing side effects or increasing the rate of side effects,” lead author Nicholas DeVito, MD, assistant professor of medical oncology at the Duke University School of Medicine, said in a press release.

Many drugs — from over-the-counter pain killers to chemotherapy medicines — have never been tested for their effects on the immune system. But some studies suggest that some drugs could make immunotherapy less effective, the authors say.

Those include:

• Sponsor Message

  Tylenol (chemical name: acetaminophen)

• Sponsor Message

  proton pump inhibitors (such as omerprazole, esomerprazole, and lansoprazole)

• Sponsor Message

  corticosteroids (such as prednisone, methylprednisolone, hydrocortisone, and dexamethasone)

The authors noted that there are lots of studies showing that corticosteroids can make immunotherapies less effective. And there’s evidence building that acetaminophen, which is one of the most popular painkillers, likely affects the immune system.

Not all drugs get in the way of immunotherapy. Some might actually make immunotherapy more effective:

• Sponsor Message

  antihistamines

• Sponsor Message

  statins

• Sponsor Message

  selective serotonin reuptake inhibitors (SSRIs)

• Sponsor Message

  GLP-1 drugs, including Ozempic and Mounjaro

Antihistamines, which are popular for treating allergies, could boost certain immune cells that help fight cancer. And some early evidence in animals suggests that SSRIs could also help suppress tumors. 

With more research, doctors will be better equipped to tell you which drugs can affect cancer treatments you’re receiving.

In the meantime, keep track of all the medicines you take and share that information with your healthcare team. If you’re receiving immunotherapy, talk to your doctors about whether it’s safe to take other over-the-counter and prescription medications.