Siliq (brodalumab) is a brand-name prescription medication. The Food and Drug Administration (FDA) has approved it to treat moderate to severe plaque psoriasis in certain adults.

Specifically, you must be able to have light therapy or systemic treatment, which affects the whole body. You also must have already tried other systemic treatments that did not work for you.

Here are some fast facts about Siliq:

  • Active ingredient: brodalumab, which is a biologic
  • Drug class: human interleukin-17 receptor A (IL-17RA) blocker
  • How it’s given: subcutaneous injection using a prefilled syringe
  • FDA approval year: 2017

If Siliq works for you, your doctor will likely recommend using this medication long term.

As with other drugs, Siliq can cause side effects. Read on to learn about potential common, mild, and serious side effects. For a general overview of this drug, including details about its uses, see this article.

Siliq 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 Siliq in clinical trials:

  • diarrhea
  • fatigue
  • nausea
  • muscle pain
  • injection site reaction (such as itching or bruising) where Siliq was injected

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

Mild side effects that have been reported with Siliq include:

  • diarrhea
  • fatigue
  • nausea
  • muscle pain
  • joint pain
  • mouth or throat pain
  • injection site reaction (such as itching or bruising) where Siliq was injected
  • infection,* such as the flu or an ear infection
  • headache*
  • mild allergic reaction*

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 side effects of the medication. If you develop a side effect with Siliq and want to tell the FDA about it, visit MedWatch.

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

Siliq may cause serious side effects. Although serious side effects were not common with this medication, they may occur. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Siliq’s prescribing information.

If you develop serious side effects with Siliq, 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:

* To learn more, see “Side effect specifics” below.
Siliq has a boxed warning for this side effect. This is a serious warning from the Food and Drug Administration (FDA).
An allergic reaction is possible after using Siliq. However, it’s not clear whether this side effect occurred in clinical trials.

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

Should I expect side effects after stopping Siliq treatment?

You should not experience side effects of Siliq after stopping treatment with the drug. However, you may notice your plaque psoriasis worsen. Siliq works to ease symptoms of the condition. If you stop using Siliq, symptoms of plaque psoriasis will likely return.

If you’re interested in stopping treatment with Siliq, be sure to talk with your doctor. They may recommend a different medication to treat your plaque psoriasis.

Does Siliq cause anger as a side effect?

It’s possible that Siliq will cause mood changes, such as anger, as a side effect. Anger is not one of the more common side effects* of Siliq.

If you notice any changes in your behavior or mood during Siliq treatment, be sure to tell your doctor right away. The drug has a boxed warning for the risk of suicidal thoughts and behaviors. This is a serious warning from the Food and Drug Administration (FDA). For details, see “Suicidal thoughts and behaviors” in “Side effect specifics” below.

In some cases, if you experience anger or other mood or behavior changes, your doctor may recommend a treatment option other than Siliq. You can talk with them to find out more.

* To learn about more common side effects, see “More common side effects of Siliq” above.

Can Siliq affect my blood or blood pressure?

Siliq may affect your blood. However, the drug should not change your blood pressure.

Siliq can cause neutropenia, which refers to a low level of a type of white blood cell called neutrophils. These cells help fight infection. With low levels of white blood cells such as neutrophils, you may get infections more easily. To help prevent this, your doctor may check your neutrophil and other white blood cell levels during Siliq treatment.

Siliq is not known to affect blood pressure. People using this medication in clinical trials did not report changes in blood pressure. It’s possible that other plaque psoriasis medications, such as Gengraf (cyclosporine) or Rayos (prednisone), may increase the risk of high blood pressure.

If you have concerns about developing blood problems during treatment with Siliq, talk with your doctor. They can also answer questions you have about blood pressure and the drug.

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

Infection

It’s possible to experience more infections during Siliq treatment. This is because the medication may weaken your immune system. When your immune system is healthy, it fights infection. If your immune system isn’t as strong as usual, it may not be able to fight infection well. Therefore, a weakened immune system can increase your risk of infection.

Most infections reported by people using Siliq in clinical trials were mild. These included the flu and ear infections. However, it’s also possible for more serious infections to occur, such as meningitis (inflammation of the brain and spinal cord membranes).

Symptoms vary depending on the type of infection you have, but in general, they can include:

  • fever or chills
  • cough
  • difficulty breathing
  • sore throat
  • diarrhea
  • burning when you urinate
  • painful skin or sores

What you can do

If you have symptoms of an infection (see above), see your doctor. They may prescribe an antibiotic or other medication to treat it. If you have a severe infection, in some cases, your doctor may recommend pausing your use of Siliq until the infection clears up.

Also, be sure to tell your doctor if you have a history of infections that won’t go away or infections that keep coming back. To learn more, see “Other precautions” in “Precautions for Siliq” below.

Headache

When compared with other side effects of Siliq, headaches were commonly reported by people who used the medication in clinical trials. However, overall, most people who used Siliq in these trials did not experience headaches.

What you can do

If you have headaches during your treatment with Siliq, talk with your doctor. They may be able to recommend ways to help ease them. For example, your doctor may recommend taking an over-the-counter pain medication, such as Tylenol (acetaminophen) or Advil (ibuprofen).

Allergic reaction

As with most drugs, Siliq 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 lips, eyelids, feet, or hands
  • 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 using Siliq. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Suicidal thoughts and behaviors

Siliq has a boxed warning for the risk of suicidal thoughts and behaviors during treatment. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). The purpose of a boxed warning is to alert doctors and patients about the risks of taking a medication.

Suicidal thoughts and behaviors were not common with Siliq. Rarely, death by suicide occurred. Because of these risks, Siliq is available only through the Siliq Risk Evaluation and Mitigation Strategy (REMS) Program. You, your doctor, and your pharmacy will need to enroll. The program’s goal is to educate on what risks to watch for and how to treat them.

What you can do

Throughout your treatment with Siliq, you, your friends, and your family should watch for mood or behavior changes. These can include new or worsening depression or anxiety, or thoughts of suicide. Your doctor will also monitor you for changes in mood. If you develop any changes, talk with your doctor right away. They can help you or refer you to a mental health professional. In some cases, they may recommend that you stop using Siliq and try a different treatment option for your plaque psoriasis.

If you have a history of suicidal thoughts or behaviors, tell your doctor before using Siliq. You may be at an increased risk of these thoughts or behaviors during your treatment. Your doctor may monitor you more often for symptoms such as mood or behavior changes. In some cases, they may recommend a different treatment option for you.

Due to these risks, your doctor may limit how long you use Siliq. If the drug does not help ease your plaque psoriasis symptoms after 12 to 16 weeks, your doctor will likely recommend a different treatment.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The National Suicide Prevention Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Click here for more links and local resources.

Before you start using Siliq, be sure to tell your doctor about any other medical conditions that you have. They can help you determine if Siliq may be safe for you.

Boxed warning: Risk of suicidal thoughts and behaviors

This drug has a boxed warning for the risk of suicidal thoughts and behaviors. This is a serious warning from the Food and Drug Administration (FDA). For details, see “Side effect specifics” above.

Other precautions

Be sure to talk with your doctor about your health history before you use Siliq. 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:

Mental health conditions. If you have a mental health condition, tell your doctor before starting Siliq treatment. This medication may worsen certain conditions, such as depression, anxiety, or other mood changes. So if you already have a mental health condition, Siliq can make your symptoms worse. In fact, Siliq has a boxed warning for the risk of suicidal thoughts and behaviors. This is a serious warning from the FDA. For details, see “Side effect specifics” above.

Your doctor may recommend monitoring your mood more often. In some cases, they may prescribe a different treatment option.

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

Infections that will not go away or keep coming back. If you have any infections that are not getting better or keep coming back, tell your doctor before starting Siliq treatment. This medication may increase your risk of infection. And if you already have an infection, Siliq may worsen it. Your doctor will likely recommend a treatment for the infection before you start using Siliq.

Tuberculosis. If you have or have had tuberculosis (TB), tell your doctor before using Siliq. TB is a type of bacterial infection that often affects the lungs.

Siliq may weaken your immune system. If you have active TB (meaning you have symptoms) and use Siliq, it could be harder for your immune system to fight the infection. This could cause the TB to worsen.

In some cases, you may have latent TB (meaning TB is in your body, but you do not have symptoms). Siliq can activate the bacteria that cause TB. If this occurs, you could develop symptoms, and the drug may worsen them.

Your doctor will test you for TB before you start treatment with Siliq. If you have TB, they’ll likely treat it before you use Siliq. They’ll also monitor you throughout and after your Siliq treatment for symptoms of TB returning. These can include any of the TB symptoms listed in “Serious side effects” above, such as cough or night sweats.

Vaccination. Your doctor will likely discuss vaccinations with you before you begin using Siliq. This is because you should not get any live vaccines during treatment with the drug.

Live vaccines have weakened live pieces of the bacterium or virus they’re meant to fend off. If you have a healthy immune system, live vaccines typically will not cause infection. However, if your immune system is weak, live vaccines could cause infection. (Siliq may weaken your immune system.) An example of a live vaccine is the nasal flu vaccine FluMist.

Due to this risk, your doctor can help determine if you may need any vaccines before you start Siliq treatment.

Crohn’s disease. It’s important to tell your doctor if you have Crohn’s disease because Siliq may worsen it. Due to this risk, doctors typically will not prescribe Siliq if you have Crohn’s disease. You can ask your doctor about other treatment options.

Alcohol with Siliq

There aren’t any known interactions between alcohol and Siliq. However, it’s possible that alcohol may worsen some side effects of Siliq. For example, both alcohol and Siliq can cause nausea and headache. Drinking alcohol during your treatment with Siliq may increase your risk of these side effects.

In addition, alcohol can make psoriasis symptoms worse. Alcohol may increase the risk of inflammation.

If you’re interested in drinking alcohol during your treatment with Siliq, talk with your doctor. They can advise you on whether it’s safe.

Pregnancy and breastfeeding while using Siliq

Here’s some information about pregnancy and breastfeeding while using Siliq.

Pregnancy. It’s not known if it’s safe to use Siliq while pregnant. There have not been any clinical trials to determine if the drug may affect pregnancy or a developing fetus.

In animal studies, no congenital anomalies (also known as birth defects) were reported in the offspring of animals given Siliq during pregnancy. However, animal studies do not always indicate what may happen in humans.

If you’re pregnant or planning to become pregnant, talk with your doctor before starting Siliq treatment. They can advise you on the risks and benefits of the drug.

Breastfeeding. It’s not known if it’s safe to breastfeed while using Siliq. It’s unknown if the drug passes into breast milk or what effects it may have on a child who is breastfed.

If you’re breastfeeding or considering it, talk with your doctor before you begin treatment with Siliq. They can help you weigh the pros and cons of the medication.

Most side effects of Siliq are mild. However, it’s possible to develop severe side effects from this medication, as well. Be sure to talk with your doctor if you have severe side effects from Siliq.

If you’d like to learn more about Siliq, talk with your doctor or pharmacist. They can help answer any questions you have about side effects of 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.