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Plegridy is an injection given under the skin or into a muscle to treat certain types of multiple sclerosis. The most common side effects are flu-like symptoms, including fever and chills. Serious side effects are less common but may include liver, heart, skin, blood vessel, or mental health problems. Notify your health care provider right away if you have new or worsening depression, anxiety, or thoughts of suicide.

Uses

What is Plegridy used for?

Plegridy (peginterferon beta-1a) is commonly used to treat certain forms of multiple sclerosis, such as clinically isolated syndrome (CIS), relapsing-remitting disease, and active secondary progressive disease.

Plegridy may also be used for other conditions as determined by your health care provider.

How does Plegridy work (mechanism of action)?

Multiple sclerosis (MS) is a condition where the immune system attacks the central nervous system (CNS), causing inflammation, damage to the protective covering of nerves, and loss of nerve function. Plegridy is similar to a natural protein called interferon. It seems to help people with MS by reducing inflammation in your body by changing the balance of cytokines (chemical messengers that regulate cell growth and activity). 

How is Plegridy supplied (dosage forms)?

Brands and other names

  • Plegridy

Dosage forms and strengths

  • 63 mcg/0.5 mL, 94 mcg/0.5 mL, 125 mcg/0.5 mL single-dose prefilled syringe
  • 63 mcg/0.5 mL, 94 mcg/0.5 mL, 125 mcg/0.5 mL single-dose autoinjector

How should I store Plegridy?

Plegridy should be stored in the original carton (to protect from light) in a refrigerator, between 36 F and 46 F (2 C and 8 C) until you are ready to inject it. If needed, Plegridy may be stored at room temperature, up to 77 F (25 C), for up to 30 days. Do not freeze it. 

Side Effects

What are the most common side effects of Plegridy?

The most common side effects of Plegridy are listed below. Tell your health care provider if you have any of these side effects that bother you.

  • Fever, chills, or flu-like symptoms
  • Headache
  • Muscle or joint pain
  • Feeling unusually weak or tired
  • Injection site reactions (see below)

There may be other side effects of Plegridy not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of Plegridy?

While less common, the most serious side effects of Plegridy are described below, along with what to do if they happen.

Severe Allergic Reactions. Plegridy may cause allergic reactions, which can be serious. Stop using Plegridy and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Liver Damage. New or worsening liver damage, also called hepatotoxicity, can happen when using Plegridy. This can be serious and can lead to liver failure and death. Call your health care provider right away if you have any of the following symptoms of liver problems, or if any previous symptoms become worse.

  • Nausea, vomiting, or diarrhea
  • Stomach or belly pain or swelling
  • Fever
  • Weakness or unusual tiredness or sleepiness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Easy bruising or bleeding
  • Confusion
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Depression, Suicidal Thoughts, or Other Mental Health Conditions. Plegridy may cause depression or suicidal thoughts or actions in a small number of people. If you are about to harm yourself, call 911 or call or text 988, the Suicide & Crisis Lifeline. Call your health care provider right away if you have any of the following symptoms.

  • New or worsening depression or anxiety
  • Thoughts of hurting yourself or suicide
  • Nervousness
  • Irritability

Injection Site Reactions. Redness, itching, or pain at the injection site are common with Plegridy. It may also rarely cause severe damage to the skin and tissue near the injection site. You should not inject Plegridy into an area where skin is irritated, red, bruised, infected, or scarred. Avoid injecting Plegridy in the same spot over and over. Call your health care provider right away if you have any of the following symptoms. 

  • Swelling at the injection site
  • Fluid draining from the injection site
  • Breaks in your skin with discolored skin (blue/black)

Heart Problems. Plegridy may cause or worsen heart problems, including heart failure, low blood pressure, fast or abnormal heart beat, chest pain, heart attack, or a heart muscle problem (cardiomyopathy). Tell your health care provider right away if you have any of the following symptoms of heart problems.

  • Shortness of breath or trouble breathing, especially while lying down
  • Chest pain or tightness
  • Difficulty exercising
  • Swelling in your feet, ankles, or legs
  • Peeing frequently, especially at night
  • Unusually fast weight gain
  • Unusual tiredness
  • Fast or abnormal heart beat

Blood Disorders. Plegridy can cause blood disorders such as low platelet levels (thrombocytopenia) and low white blood cell levels (neutropenia). Tell your health care provider right away if you have any of the following symptoms of blood disorders.

  • Fever
  • Shortness of breath
  • Pale or yellowish skin
  • Easy bruising or bleeding
  • Frequent infection
  • Unusual weakness or tiredness
  • Dizziness, lightheadedness, or feeling like you are about to pass out
  • Headache
  • Fast or abnormal heartbeat

Small Blood Vessel Injury. Plegridy can lead to a serious problem with blood clotting, called thrombotic thrombocytopenic purpura (TTP). TTP is when blood clots form in some parts of your bloodstream, which reduces platelets in the rest of the blood (thrombocytopenia). If the blood vessel damage happens in your kidneys, it can lead to hemolytic uremic syndrome (HUS). This can lead to kidney failure. These conditions need to be treated right away in the hospital or they can lead to death. Get emergency help if you have any of the following symptoms without another explanation.

  • Fever
  • Shortness of breath
  • Pale or yellowish skin or your skin or the whites of your eyes turn yellowish (also called jaundice)
  • Changes in your vision
  • Unusual weakness or tiredness
  • Headache, confusion, or slurred speech
  • Fast heartbeat
  • Purplish spots (purpura) on the skin or in the mouth due to bleeding under the skin
  • Reduced need to pee, a low amount of pee, or pee that is pink or has blood in it
  • Swelling in your feet, ankles, or legs
  • Chest pain or pressure
  • Nausea
  • Seizures

Pulmonary Arterial Hypertension. Plegridy may cause pulmonary arterial hypertension, which is high blood pressure in the blood vessels (arteries) of the lungs. This can happen soon after or even years after you start using Plegridy. Call your health care provider right away if you have shortness of breath or tiredness that is new or getting worse.

Autoimmune Conditions. Plegridy may cause a new autoimmune condition, which means the immune system attacks the body’s own tissues. These conditions may include low platelets, thyroid problems, or liver problems. Keep all appointments, including blood tests, to help your health care provider monitor you for these conditions. 

Seizures. Some people who have used Plegridy have reported having seizures, even if they never had seizures before. There are many different types of seizures and some of them are not easy to recognize. Call your health care provider right away if you have any of the following signs that a seizure is happening or could happen.

  • Muscle twitching, jerking, spasms, tremors, or other uncontrolled movements
  • Stiffening of your arms and legs
  • Feeling anxious, nervous, confused, or a sense of dread
  • Feeling dizzy or lightheaded
  • Falling or losing consciousness

Warnings & Precautions

Who should not use Plegridy?

Allergies to Ingredients. People who are allergic to any of the following should not use Plegridy.

  • Peginterferon beta-1a
  • Plegridy
  • Interferon beta
  • Peginterferon
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in Plegridy.

What should I know about Plegridy before using it?

Do not use Plegridy unless it has been prescribed to you by a health care provider. Use it as prescribed and carefully follow your dosing schedule. This medicine is injected under the skin or into a muscle. Read and follow the “Instructions for Use” that come with your medicine. Make sure that you or a caregiver understands how to properly prepare and use Plegridy. If you have any questions, talk to your health care provider.

Do not share Plegridy with other people, even if they have the same condition as you. It may harm them.

Keep Plegridy out of the reach of children. Since this medicine should be kept in a refrigerator, take special precautions to keep it away from children who also use the refrigerator.

Each Plegridy syringe or autoinjector should only be used one time. You should use a new one for each injection. Throw away any unused medicine after injecting your dose. Do not reuse needles or syringes or share them with other people. Throw them away in a sharps container. 

You should rotate where you inject Plegridy. Do not inject Plegridy into skin that is irritated, red, bruised, infected, or scarred. Evaluate the injection site for redness, swelling, and tenderness about two hours after you inject it. Call your health care provider if you have any skin reactions that do not go away in a few days. 

Plegridy can cause flu-like symptoms, including fever, chills, muscle and joint aches, tiredness, and headache. This may be more likely to happen when you first start using Plegridy. Your health care provider may recommend over-the-counter pain or fever medicines to help with these symptoms. Try to drink plenty of water (to prevent dehydration) while using Plegridy.

What should I tell my health care provider before using Plegridy?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if Plegridy is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your health care provider if you have or have had any of the following.

  • Mental health conditions, including depression or thoughts of suicide
  • Liver or kidney problems
  • Low blood cell counts or bleeding problems
  • Heart problems, including heart failure
  • Thyroid problems
  • Any other kind of autoimmune problem
  • Seizures
  • Pulmonary arterial hypertension

Rubber or Latex Allergy. Plegridy contains natural rubber latex and may cause allergic reactions in some people. Tell your health care provider if you are allergic to rubber or latex. 

Pregnancy. It is not known if or how Plegridy could affect pregnancy or harm an unborn baby. Tell your health care provider if you are pregnant or plan to become pregnant. Your health care provider will advise you if you should use Plegridy while you are pregnant or trying to get pregnant. Tell your health care provider right away if you become pregnant while using Plegridy.

Breastfeeding. Plegridy passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will advise you if you should use Plegridy while breastfeeding.

 

How can I get more information about Plegridy?

For more information about Plegridy, you can visit the manufacturer’s website at www.plegridy.com or call them at 800-456-2255.

Interactions

Does Plegridy interact with foods or drinks?

There are no known interactions between Plegridy and foods or drinks.

It is unknown if drinking alcohol will affect Plegridy, but both Plegridy and alcohol can lead to liver damage. It is best to limit the amount of alcohol you drink while using Plegridy. 

Does Plegridy interact with other medicines (drug interactions)?

There are no known interactions between Plegridy and other medicines. Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much Plegridy?

If you or someone else has used too much Plegridy, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of Plegridy?

If you miss a dose, use it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only use the next dose. Do not use double or extra doses. If you miss a dose and are not sure what to do, ask your health care provider.