Orserdu (elacestrant) is a brand-name oral tablet prescribed for specific types of advanced breast cancer in certain adults. As with other drugs, Orserdu can cause side effects, including muscle and joint pain, nausea, and increased cholesterol.

Orserdu can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Orserdu in clinical trials:

* For more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Orserdu use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Orserdu’s prescribing information.

Mild side effects that have been reported with Orserdu include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Orserdu and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.
† An allergic reaction is possible after taking Orserdu. However, it’s not clear whether this side effect occurred in clinical trials. To learn more, see “Side effect specifics” below.

Orserdu may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Orserdu’s prescribing information.

If you develop serious side effects while taking Orserdu, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

* An allergic reaction is possible after taking Orserdu. However, it’s not clear whether this side effect occurred in clinical trials. To learn more, see “Side effect specifics” below.

Orserdu may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Can Orserdu cause long-term side effects?

It’s not clear. In clinical trials of Orserdu, a few side effects were reported that could possibly last long term. An example is high cholesterol.* However, it’s not clear from these trials whether these side effects lasted for a long time.

Talk with your doctor or pharmacist if you have concerns about long lasting side effects from taking Orserdu.

* This is a serious side effect of Orserdu. To learn more, see “Serious side effects of Orserdu” above.

How do side effects of Orserdu compare with those seen with Faslodex?

Some but not all side effects of Orserdu are the same as those of Faslodex (fulvestrant). Faslodex is a brand-name drug prescribed to treat certain types of breast cancer after menopause. Orserdu is also prescribed for this condition. Both Faslodex and Orserdu are a type of hormone therapy for breast cancer.

Side effects that can occur with either drug include:

Faslodex may cause side effects that are not common with Orserdu. These include hair loss, back pain, and bleeding and bruising easily.

If you’d like to know more about how Orserdu and Faslodex compare, talk with your doctor. They can also advise you on the treatment option that’s right for your condition.

* This is a serious side effect of Orserdu. To learn more, see “Serious side effects of Orserdu” above.
† For more information about this side effect, see “Side effect specifics” below.

Learn more about some of the side effects that Orserdu may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Orserdu.

Nausea

In clinical trials of Orserdu, nausea was the most common side effect. This side effect can be mild to severe. In fact, some people stopped Orserdu treatment due to nausea.

What you can do

Orserdu, similarly to other medications, can upset your stomach. An upset stomach can make you feel nauseous. If you experience mild nausea, it may be helpful to take Orserdu with food. A small snack or meal before your dose can help minimize nausea and stomach upset.

Be sure to tell your doctor if the above doesn’t help or your nausea is severe. They may lower your Orserdu dosage or recommend that you stop taking the drug.

Hot flashes

Hot flashes were reported by some people who took Orserdu in clinical trials. Hot flashes involve a sudden sensation of intense heat in the upper body (typically in the face, neck, and chest).

What you can do

Certain lifestyle changes may help reduce hot flashes. Strategies you may try include:

  • Eat a nutritious diet.
  • Exercise regularly to promote sleep and manage stress.
  • Practice activities that help lower stress, such as yoga and deep breathing.
  • Limit or eliminate alcohol and caffeine intake before bedtime.
  • Avoid smoking and secondhand smoke.
  • Limit your intake of excessively spicy foods.
  • Maintain a comfortable body temperature by wearing loose-fitting cotton clothing. It may be helpful to dress in layers so you can easily adjust to a change in temperature.

For more guidance about managing hot flashes, talk with your doctor.

Allergic reaction

As is possible with most drugs, Orserdu can cause an allergic reaction in some people. However, it’s not clear whether this side effect occurred in clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Orserdu. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Orserdu. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health. These are considered drug-condition or drug-factor interactions. The conditions and factors to consider include:

Pregnancy or breastfeeding. If you’re pregnant or breastfeeding your child, Orserdu is not considered safe for your pregnancy or your child. Before taking this drug, tell your doctor if you’re pregnant or can become pregnant. They’ll likely advise you to use birth control while taking Orserdu and for at least 1 week after you finish treatment.

If you’re breastfeeding your child, your doctor will likely offer similar guidance. They’ll advise you to refrain from breastfeeding until at least 1 week after you finish treatment. Your doctor can recommend other ways to feed your child while taking Orserdu.

Alcohol consumption. It’s likely safe to consume alcohol while taking Orserdu. No interactions were observed between Orserdu and alcohol consumption in clinical trials. Talk with your pharmacist or doctor if you have questions about how much alcohol is safe to drink while taking Orserdu.

Liver problems. Orserdu treatment may affect your liver. If you have a liver condition such as hepatitis, tell your doctor before beginning Orserdu. Your doctor will determine whether it’s the right treatment option for you.

Allergic reaction. If you’ve had an allergic reaction to Orserdu or any of its ingredients, your doctor will likely not prescribe Orserdu. Ask your doctor what other medications may be better options for you.

If you’d like to learn more about Orserdu, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.