Side Effects of Biologics

Types, Prevention, and Management

Most people who take biologic type therapies do well with them. Though they might experience a side effect or two, they are able to manage these problems without too much difficulty. For most people who choose to try these therapies, the benefits outweigh these potential problems.

However, some people taking biologic treatments experience more significant issues from their use. All biological agents come with certain risks. It’s worth learning about the possible side effects and adverse events that these products sometimes cause. That will help you make the best possible decisions concerning your health. You’ll also know when you might need to seek medical attention.

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What are Biologics?

Biologics refer to a large class of therapeutic treatments that are manufactured based on some component of a living organism. Many biologics target a component of the person’s immune system. They are typically modified versions of various proteins. Because of this, most are taken via injection or infusion and cannot be taken by mouth. Also, they aren’t broken down in the body in the same way as non-biologic drugs.

Like standard pharmaceuticals, biologic treatments can cause adverse drug reactions. They can cause allergic reactions similar to the ways these drugs can. But they can also cause problems due to the way biologics interact with the immune system. They can also sometimes cause specific problems with various organ systems in the body. Often these problems are mild, but sometimes they can be quite serious.

Thinking about Side Effects in Biologics

Biologics encompass a wide array of diverse therapies, including older therapies like vaccines and much newer ones like gene therapy. This article focuses primarily on the side effects of the widely used biologic treatments used to treat certain autoimmune and inflammatory disorders (such as rheumatoid arthritis, inflammatory bowel disease, and psoriasis) as well as certain kinds of cancers.

Certain classes of biologics may have some similarities in terms of their side effects. For example, infliximab (Remicade), etanercept (Enbrel), and adalimumab (Humira) are examples of a type of biologic TNF inhibitors. Because they work in a similar way, you might expect them to have some overlapping potential side effects. However, each individual biologic has undergone its own clinical studies, and researchers sometimes find that certain biologics carry specific risks.

If you’ve had trouble with a certain type of biologic, you may find you do better with another drug in that same class. You might choose to switch from an infusion based biologic to an injection based biologic. Or you may be better off with a biologic treatment with a different mechanism. Or you might want to go with a non-biologic treatment, if that’s an option.

Your clinician and pharmacist can help educate you on the specific risks and side effects associated with your biologic treatment. But remember, you may not experience any problems from your biologic treatment. It’s impossible to know ahead of time who might have issues. Also, particularly for newer biologics, we may still be learning about potential long-term side effects of treatment.

Types of Side Effects of Biologics

Injection site reactions

This is the most common type of side effect from biologic treatments given via an injection. These refer to various reactions where the injection is given. For example, symptoms might include:

●      Burning or stinging

●      Red rash

●      Itching

●      Swelling

●      Bruising

●      Soreness

The symptoms may last up to a week or so.

Infusion reactions

Infusion reactions are an important type of potential side effect of biologic therapies. These reactions typically occur within an hour or so of receiving an infusion of a biologic, sometimes occur within minutes. Because these reactions are potentially more serious than those occurring from injectable biologics, drugs that are infused should usually be given in a monitored healthcare setting.

Such reactions might cause signs and symptoms like the following:

●      Headache

●      Dizziness

●      Itchiness

●      Nausea and vomiting

●      Diarrhea

●      Flushing

●      Rash

●      Fever

●      Heart palpitations

●      Joint and muscle pains

Usually these reactions are mild. However, sometimes they may be more severe and require medical intervention. This is more likely if something called a hypersensitivity reaction is happening. (This is sometimes also called an anaphylactic reaction, a severe type of allergic reaction.) Such a person might have itchy, red welts on the skin, skin swelling, difficulty breathing, and severely lowered blood pressure. Such an intense reaction may even be life-threatening.

The risk of having an infusion reaction will vary based on the specific biologic. Just as a general reference point, one study found that the biologic infliximab was associated with an infusion reaction in about 10% of people.

Depending on the type of reaction, a person might not have symptoms with their first infusion but only after the second time they receive treatment.

Other Adverse Reactions

Many other systems of the body can also be affected by biologics. Again, the specific risks will vary based on the individual biologic treatment, and most of these risks are rare for any specific biologic. However, different biologics have sometimes caused additional problems like the following:

●      Liver problems

●      Skin symptoms (like psoriasis or atopic dermatitis)

●      Interstitial lung disease or other lung problems

●      Low blood counts (causing anemia and increased risk of bleeding and infection)

●      Lupus-like immunological syndromes

●      Increased risk of cardiac events

●      Neurological syndromes (like peripheral neuropathies)

●      Gastrointestinal complications (like perforated bowel)

This represents only a portion of potential issues. The severity of these problems can range from mild to life-threatening.

Some biologics can also cause specific side effects in people who have other health conditions. For example, a biologic might worsen your disease if you already have congestive heart failure. The same might be true for people who have COPD. In some cases, your clinician will recommend that you not try a certain biologic therapy if you have another medical condition that increases your risk of certain side effects.

It’s important to realize that the risk of these problems is not the same for every biologic. For example, gastrointestinal complications tend to be more common in the biologic Actemra (tocilizumab) than for other kinds of biologics. That’s why it’s important to know the particular risks most associated with your treatment.

Cancer Risks

Because many biologics impact the immune system, there is a potential risk that they may reduce the body’s ability to destroy cancerous cells. It’s for this reason that people have carefully studied whether taking different kinds of biologics might increase a person’s risk for specific cancers. It can be challenging to study this, as certain conditions that can be treated with biologics are associated with an increased of certain cancers, even without biologic treatment.

Many medical studies have been performed on this topic, and some of them have had different conclusions. Some evidence suggests that some biologics may slightly increase the risk of certain cancers. For example, it does seem to be the case that TNF inhibitors (such as those used to treat rheumatoid arthritis and IBD) slightly increase the risk of getting melanoma. However, it’s important not to get an over-exaggerated sense of these risks. You’ll want to talk to your healthcare provider about the risks of cancer associated with your particular biologic as well as your other risk factors for cancer.

Infection Risks

Other potential effects have to do with a person’s immune system. Certain biologics block parts of a person’s immune response. While this can be very helpful if a person is having an overactive immune response, it may leave one more vulnerable to certain kinds of infection.

More prone to serious infections

In general, you may be more likely to have a difficult time fighting off a pathogen if you are taking a biologic medication. You may be more likely to end up in the hospital than you otherwise would. You also may be more likely to have problems with a pathogen that normally doesn’t cause serious infection.

By some estimates, a serious infection affects between 2% to 5% of people taking a biologic medication for every year they are taking the drug, though different biologics have different risks in this area. Upper respiratory infections appear to be the most common type of serious infection, though these can occur in many other body systems. The risk of serious infection is higher if you are taking another medication that suppresses the immune system.

Infection reactivation

Infection reactivation can also be a problem. For example, some people are carriers of the hepatitis B virus. That means they are infected with the virus, but don’t have an active infection that’s causing them problems. In some cases, treatment with a biologic might reactivate the virus. This might lead to problems with their liver.

Something similar is true of tuberculosis (TB). Some people may be infected with TB bacteria even though they don’t have an active infection causing them any problems. If treated with certain biologic therapies, such an infection might reactivate, causing symptoms like shortness of breath.

That’s why healthcare providers need to check ahead of time to make sure you aren’t carrying these sorts of infections. They also monitor you to make sure such infections haven’t become active.

Management of Side Effects

Management of side effects will depend on the nature of the side effect and its intensity. Some may not impact your life very much, and you may be able to manage them without much problems. Something simple, like an over-the-counter pain reliever, may be all that you need. Other times, you’ll need to stop taking a particular biologic. You may be able to switch to another biologic of a similar type, to a biologic of a different type. Or you may need to start another type of treatment.

Injection Side Effects

Side effects from injections usually go away on their own. But if you are having problems, it may be helpful to vary the site of injection. Topical medications like corticosteroids and analgesics can also be helpful to reduce side effects. Usually people don’t need to stop taking their biologic if they have this type of reaction.

Infusion Side Effects

If you have infusion side effects, your healthcare provider will probably stop the infusion, at least temporarily. Depending on the situation, you might need treatment to get your symptoms under control, such as:

●      Acetaminophen for pain relief

●      Antiihistamine

●      Steroids

●      Epinephrine

If you are having a severe reaction, you might need acute medical attention to get your symptoms safely under control. That’s why it’s beneficial to get infusion-type biologics in a monitored healthcare setting.

Prevention of Side Effects

General Side Effect Prevention

An important part of prevention is done in your initial medical assessment before starting therapy. You may need tests to assess whether you have other medical conditions, such as congestive heart failure or certain neurological conditions. If so, you might need to take a different biologic drug. Or you might need to avoid biologics completely.

Preventing Infusion Reactions

To help prevent infusion reactions, some medical institutions pretreat people receiving certain types of biologics, like TNF-inhibitors. For example, you might receive acetaminophen, an antihistamine, and intravenous steroids a little before your infusion. However, this protocol is not standard, and it is not necessary for all type of biologics.

You are more likely to need pre-treatment if you have had an infusion reaction in the past. In that case, your clinician is particularly likely to recommend using treatments such as pain medication, antihistamines, and steroids for future infusions, to help prevent future reactions. Using slower infusion rates may also be helpful for prevention.

In some cases, you may need to switch to another biologic or nonbiologic treatment. This is more likely if you have an extreme infusion reaction as opposed to a mild one that was easily managed. Ask your healthcare provider what you can expect in your particular situation.

Infection and Cancer Prevention

You can’t get specific vaccines (the “live” variety) while taking certain kinds of biologic treatments. So your healthcare provider may recommend that you get certain vaccines before you start your biologic. For example, you might need to get a vaccine for hepatitis B or for herpes zoster (which causes shingles). In general, your vaccines should be up-to-date before you start biologic therapy.

It's also important that your healthcare provider screen you for any cancers prior to starting therapy. You’ll also need to be monitored during your treatment.

Getting the Information Without Getting Overwhelmed

It’s a good idea to look at the full prescribing information on the prescription for your biologic treatment. You can also look up the information online by searching for the FDA label for a given biologic. That provides a comprehensive list of the possible side effects or problems your treatment might cause. It’s especially important to be aware of any potential signs or symptoms that might need immediate medical attention.

But try not to get overwhelmed or overly worried by this process. These sources include detailed information about the most severe problems from these drugs, which are uncommon. If such side effects weren’t uncommon, the biologic never would have been approved by the FDA. Also, remember that all medical treatments have risks. Though biologics do have potential adverse effects, your other medical options, such as non-biologic pharmaceutical therapy, come with their own sets of possible problems as well.

But if you still have concerns about the risks involved, don’t hesitate to discuss them with your healthcare provider. Biologics do have real risks and potential side effects, so it’s better to be informed. That way, you can make the right choice for you. 

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Khan DA. Hypersensitivity and immunologic reactions to biologics: opportunities for the allergist. Ann Allergy Asthma Immunol. 2016;117(2):115-20. doi:10.1016/j.anai.2016.05.013

  2. American College of Rheumatology. TNF Inhibitors.

  3. Sârbu, MI, Tampa M; Mitran MI, et al. Adverse reactions of biological therapies in patients with psoriasis. Journal of Mind and Medical Sciences: 2017;4(1): Article 3. doi:10.22543/7674.41.P0412

  4. Boyman O, Comte D, Spertini F. Adverse reactions to biologic agents and their medical management. Nat Rev Rheumatol. 2014;10(10):612-27. doi:10.1038/nrrheum.2014.123

  5. American College of Rheumatology. Patient Safety and Site of Service for Biologics. Position Statement.

  6. Cheifetz A, Smedley M, Martin S, Reiter M, et al. The incidence and management of infusion reactions to infliximab: a large center experience. Am J Gastroenterol. 2003;98:1315-24.

  7. Curtis JR, Singh JA. Use of biologics in rheumatoid arthritis: current and emerging paradigms of careClin Ther. 2011;33(6):679–707. doi:10.1016/j.clinthera.2011.05.044

  8. McLean LP, Cross RK. Adverse events in IBD: to stop or continue immune suppressant and biologic treatmentExpert Rev Gastroenterol Hepatol. 2014;8(3):223–240. doi:10.1586/17474124.2014.881715

By Ruth Jessen Hickman, MD
Ruth Jessen Hickman, MD, is a freelance medical and health writer and published book author.