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Plegridy (peginterferon beta-1a)

Plegridy® is an interferon beta indicated for the treatment of patients with relapsing forms of multiple sclerosis (MS). It is a disease-modifying drug (DMD). This form of peginterferon beta-1a is administered by subcutaneous injection (under the skin). An interferon, it is a group of glycoproteins produced naturally in the body in response to viral infections. Plegridy is intended to slow the build up of disabilities and reduce the incidence of relapses in people with MS.

What are the ingredients in Plegridy?

The active ingredient in Plegridy is interferon beta-1a and poly(ethylene glycol).

How does Plegridy work?

The way Plegridy works is not well understood. It is an interferon, which helps to control immune system activity. It is thought to act by reducing inflammation and the immune response that attacks myelin.

What are the possible side effects of Plegridy?

Many clinical trials evaluated the safety and efficacy of Plegridy. The most common side effects experienced by those taking Plegridy include:

  • Flu-like symptoms
  • Headache
  • Injection site reactions
  • Blood count abnormalities
  • Asthenia (feeling weak or tired)
  • Insomnia (sleeplessness)
  • Abdominal pain, diarrhea, nausea and vomiting
  • Myalgia (muscle or joint pain)
  • Infections

Flu-like symptoms can generally be treated with over-the-counter pain relief medications.

This is not an exhaustive list of all potential side effects of Plegridy. For more information, consult your doctor or healthcare provider. If you notice any new or worsening side effects when taking Plegridy, contact your doctor or healthcare provider immediately.

Things to note about Plegridy

Plegridy should be stored in the refrigerator in its original carton and protected from light. Once removed from the refrigerator, it should be allowed to warm to room temperature (about 30 minutes) prior to injection.

Before starting Plegridy, talk with your doctor if you:

  • Have a history of hypersensitivity to natural or recombinant interferon beta or peginterferon, or any other component of the formulation
  • Have hepatic (liver) injury
  • Have a history of depression or suicidal ideation. Any new symptoms of depression, suicidal ideation, and/or psychosis should be reported immediately to your doctor.
  • Have a history of seizures
  • Have a history of anaphylaxis
  • Are a congestive heart failure patient, who should be monitored for worsening symptoms
  • Are pregnant or planning to get pregnant, as there is limited information on the use of Plegridy in pregnancy. It should be used only if the potential benefit of Plegridy therapy exceeds risk to the fetus.
  • Have Thrombotic Microangiopathy (damage to small blood vessels in vital organs)
  • Experience development of new autoimmune disorders

Individuals with the above conditions should be monitored closely while taking Plegridy.

Dosing information

Plegridy is administered by subcutaneous injection with a recommended dosage of 125 micrograms injected every 2 weeks. Plegridy is titrated, starting with a dose of 63 micrograms on day 1, increasing in 2 weeks to 94 micrograms on day 15, and two weeks later to 125 micrograms, the full dose, on day 29.

Plegridy comes in a starter pack with single dose prefilled pens or syringes with different colored labels. A healthcare professional should train patients or caregivers in the proper technique for administering subcutaneous injections. Typical injection sites are the abdomen, back of the upper arm, and thigh. Sites should be rotated to minimize the chance of injection site reactions. Injections should not be administered where the skin is bruised, irritated or red, infected, or scarred. Safe disposal practices should be used for needles and syringes.

Pain and fever-reducing medication can be taken on treatment days to help reduce any flu-like symptoms.

Written by Linda Saxl Minton | Last review date: July 2019
  1. PLEGRIDY prescribing information available at: Accessed 4/16/18.