Cimerli (ranibizumab-eqrn) is a prescription biologic drug used to treat certain eye conditions, such as macular degeneration. Cimerli can cause side effects that range from mild to serious. Examples include floaters and eye pain.

Specifically, Cimerli is used in adults to treat:

The active ingredient in Cimerli is ranibizumab-eqrn.* (An active ingredient is what makes a drug work.) Cimerli comes as a liquid solution that your doctor will inject into your eye.

Keep reading to learn about common, mild, and serious side effects that Cimerli can cause. For a general overview of the drug, including details about its uses, see this article.

* The reason “-eqrn” appears at the end of the drug’s name is to show that it’s distinct from similar drugs that may be created in the future.

Below are just a few of the more common side effects reported in Cimerli’s studies. Side effects can vary depending on what condition the drug is being used to treat.

More common side effects in people receiving Cimerli injections for DR and DME include:

More common side effects in people receiving Cimerli injections for AMD include:

More common side effects in people receiving Cimerli injections for macular edema following RVO include:

  • broken blood vessel in the white of the eye
  • eye pain

Specific side effects for people with mCNV being treated with Cimerli were not reported in the drug’s studies.

Mild side effects have been reported with Cimerli. These include:

  • eye floaters
  • dry eye
  • eye or eyelid irritation, itchiness, redness or discoloration
  • broken blood vessel in the white of your eye
  • feeling like there’s something in your eye
  • eye pain
  • blurred vision
  • increased tear production
  • common cold symptoms
  • cough
  • mild allergic reaction*†

In most cases, these side effects should be temporary and clear on their own. Or they can often be managed with over-the-counter (OTC) medications. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop Cimerli injections unless your doctor recommends it.

Cimerli may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after receiving Cimerli injections, but this side effect wasn’t reported in studies.

Serious side effects have been reported with Cimerli. These include:

Deaths were reported in the drug’s studies in people with DR and DME.

If you develop serious side effects during Cimerli treatment, 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.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after receiving Cimerli injections, but this side effect wasn’t reported in studies.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Cimerli, visit MedWatch.

Get answers to some frequently asked questions about Cimerli’s side effects.

How do side effects of Cimerli compare with those of Lucentis?

Lucentis is a biologic drug, which means it’s made from living cells. Cimerli is a biosimilar* of Lucentis. Biosimilars are “similar” to the parent drug and are considered just as safe and effective. And like generics, biosimilars often cost less than the brand-name version.

The side effects observed in studies of Cimerli were similar to those seen in studies of Lucentis. Both drugs have risks of:

  • increased eye pressure
  • retinal detachment
  • severe eye infection

During Cimerli treatment, notify your doctor right away or seek immediate medical care if you develop vision changes or eye redness, drainage, pain, or sensitivity to light. These may be signs of a severe eye problem or infection.

Ask your doctor or pharmacist to recommend the best treatment for your condition.

* Drugs made from chemicals can have generics, which are exact copies of the active drug in the brand-name medication. But biologics can’t be copied exactly. So instead of a generic, biologics have biosimilars.

Does Cimerli cause long-term side effects?

It’s possible. Long-term side effects include those that may start at any time during treatment with a drug, even if you’ve taken it for a long time. It also includes side effects that may not go away, even after you stop treatment.

The risk of developing cataracts is common in people who receive any type of eye injection. However, cataracts are correctable with surgery, and this side effect usually doesn’t prohibit the use of Cimerli.

Rare occurrences of other long-term side effects are also noted in Cimerli’s studies. Examples include:

There may also be an increased risk of death for people with DR or DME who receive Cimerli treatment. However, it’s not clear how much Cimerli increases the risk, if at all.

If you’re concerned about possible long-term side effects from Cimerli, talk with your doctor or pharmacist about your risks.

Learn more about some of the side effects Cimerli may cause.

Retinal detachment

Retinal detachment was a rare side effect reported in Cimerli’s studies. Retinal detachment may cause symptoms such as:

  • a curtain-like shadow in your vision
  • flashing lights, especially in a darkened room or with closed eyes
  • floaters and black specks in your vision
  • inability to see out of the corner of your eye
  • blurred vision or sudden vision loss

Factors that can increase the risk of retinal detachment when receiving Cimerli injections include:

  • being ages 65 years and older
  • previous retinal detachment, eye injury, or surgery
  • severe nearsightedness

What might help

There’s no sure way to lower the risk of retinal detachment. But knowing what to watch for and getting a dilated eye exam from an optometrist right away when symptoms occur can help. This quick action can save your eyesight and prevent further damage.

Blood clots

Blood clots are a rare side effect reported in Cimerli’s studies. They appear to be more common in people with diabetes. Blood clots may cause symptoms of heart attack or stroke, such as:

When receiving Cimerli injections, certain factors can increase the risk of developing blood clots, which can lead to heart attack or stroke. These include:

  • having a history of circulation disease, stroke, or heart attack
  • having other conditions that increase the risk of circulation disease, such as diabetes or high cholesterol
  • taking medications that increase blood clotting risks, such as birth control pills or chemotherapy (traditional drugs used to treat cancer)

What might help

Talk with your doctor about your health history and all the medications you take before starting Cimerli. Be mindful of the symptoms of heart attack and stroke, and seek immediate medical attention if you experience any of those symptoms.

Allergic reaction

Like most drugs, Cimerli can cause an allergic reaction in some people. But this side effect wasn’t reported in Cimerli’s studies. Symptoms can be mild to serious and can include:

  • eye itchiness and redness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin (usually in your eyelids, lips, hands, or feet)
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as eye itching, slight swelling, or redness, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an oral antihistamine, such as Benadryl (diphenhydramine)
  • a cool compress applied to the area to reduce redness and swelling

If your doctor confirms you’ve had a mild allergic reaction to Cimerli, they’ll decide if you should continue treatment.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Cimerli, they may have you switch to a different treatment.

Keeping track of side effects

During your Cimerli treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start treatment with a new drug or combination of drugs.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Taking notes and sharing them with your doctor will help them learn more about how Cimerli affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before starting Cimerli.

Warnings

Cimerli can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Cimerli is a good treatment option for you. Talk with your doctor about your health history before receiving Cimerli injections. Be sure to tell them if any of the following factors apply to you:

  • active infection in or around your eye
  • previous retinal detachment, eye injury, or surgery
  • previous blood clot, stroke, or heart attack
  • severe nearsightedness
  • increased eye pressure
  • use of other medications, OTC drugs, vitamins, supplements, or herbs
  • previous allergic reaction to Cimerli
  • pregnancy
  • breastfeeding

Alcohol and Cimerli

There are no known interactions between alcohol and Cimerli. If you have questions about consuming alcohol during Cimerli treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Cimerli

There is limited information about the safety of Cimerli use during pregnancy or while breastfeeding.

Pregnancy

It’s not known whether it’s safe to receive Cimerli injections during pregnancy because the drug hasn’t been studied in pregnant people. Cimerli may be prescribed for someone who’s pregnant only if the benefits of treatment outweigh the potential risks to the fetus.

If you’re able to become pregnant, your doctor may recommend using a form of birth control during your Cimerli treatment. They may recommend a hormone-free contraceptive if your risk of blood clots is high with Cimerli use. (See the “Side effects explained” section above for more information on blood clots.)

Your doctor will likely recommend that you use birth control before receiving Cimerli injections and throughout your treatment. You may also need to continue using it for a certain amount of time after your Cimerli treatment ends.

Breastfeeding

It isn’t known whether Cimerli injections are safe to receive while breastfeeding. If you’re breastfeeding or planning to do so, talk with your doctor before starting this medication.

Like most drugs, Cimerli can cause a number of side effects that range from mild to serious. But most are temporary and go away after a few days to weeks. If you have questions about side effects that Cimerli can cause, talk with your doctor. Examples of questions to help get you started include:

  • Will Cimerli injections prevent me from driving?
  • What’s the risk of Cimerli making my vision worse?
  • What OTC eye drops can I use for a dry, itchy eye caused by Cimerli?
  • What side effects of Cimerli should prompt me to call you right away?

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Disclaimer: Healthline 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.