Glatiramer acetate injection (Copaxone) and interferon beta 1-a (Avonex) are both injectable drugs. They U.S. Food and Drug Administration (FDA) has approved them to treat relapsing-remitting multiple sclerosis (RRMS). Both drugs can help control your multiple sclerosis (MS) and slow down the rate of progression. Which one would be best for you?

Copaxone is a man-made protein. It may prevent certain white blood cells called “T cells” from damaging myelin, which is the insulating layer around your nerves. Copaxone is available in a prefilled syringe.

Avonex is an interferon that you inject once per month into a major muscle. Interferons are chemical messengers. They help regulate your immune response. They help prevent your body from attacking your central nervous system.

Avonex is available in two dosage forms and three kinds of packaging. Powdered Avonex is dissolved in liquid before injection. You can also use the premixed solution that comes in a prefilled syringe or in an automatic pen injector.

You will need some training to learn how to inject both of these drugs correctly. When deciding which medication is right for you, consider how the number of injections and the location of the injection will work for your lifestyle.

There are other differences to consider:

DosageInject 20 mg subcutaneously (under the skin) daily or inject 40 mg three times per week. Inject into a muscle once per week.
AvailabilityPrefilled syringePowder form, prefilled syringe, or automatic pen injector
CostApprox. $6000 a monthApprox. $6000 a month
Storage• Store Copaxone at 36 to 46°F. Store up to 30 days between 59 and 86°F. • Store Avonex powder between 36 and 46°F. Store up to 30 days at 77°F.

• Store Avonex prefilled syringes between 36 and 46°F. Store for up to 7 days at 77°F.

In clinical trials, researchers found no interactions between Copaxone and other drugs. There are also no known drug interactions with Avonex.

This is unusual, but both of these drugs have actions in the body that are much like naturally occurring chemicals. In the future, new drug interactions may be found. Always tell your doctor and pharmacist about all drugs and supplements you take in case new drug interactions are discovered.

Avonex Side Effects

Avonex can make you feel like you have the flu, with milder side effects like:

  • headache
  • fatigue
  • pain
  • chills
  • dizziness
  • injection site reaction
  • stomach pain
  • reduced white blood cell count, which is found with blood tests
  • reduced thyroid function, which is found with blood tests

Your doctor may tell you to take over-the-counter pain or fever reducing drugs before you inject Avonex to help reduce your risk of flu-like side effects.

Avonex can also cause more serious side effects. If you experience any of the following reactions from Avonex, call your doctor right away:

  • depression and an increased risk of suicide if you have a history of depression
  • signs of liver injury, including fatigue, yellowing of eyes or skin, or swollen or painful abdomen
  • seizures, which you are at increased risk for if you have a history of a seizure disorder
  • heart failure, especially if you have a history of heart disease

Avonex may also cause an immune reaction. Avonex is a protein, and you could develop antibodies to the drug. This could cause hives, a rash, or trouble breathing. If this happens, see your doctor right away.

Copaxone Side Effects

Milder side effects from Copaxone include:

  • nausea
  • vomiting
  • infection
  • flu
  • back pain
  • wheezing
  • cough
  • lipoatrophy, or damage to the fatty tissue under your skin

During the first few weeks or months of using Copaxone, you could have one or more serious reactions that often occur in a group. If you experience any of these reactions from Copaxone, call your doctor right away:

  • redness or flushing in your cheeks or other parts of your body
  • chest pain
  • fast heart beat
  • anxiety
  • breathing problems
  • tightness in your throat
  • swelling
  • rash
  • hives
  • itching

Many people who use the higher dose of Copaxone three times per week report fewer side effects than those who inject the smaller dose every day. You can also reduce your chances of skin changes or irritation by changing injection sites. Talk to your doctor first before doing this.

Neither Copaxone nor Avonex completely stops MS, but both can slow down the disease. They help protect you from the damaging effects of MS in different ways. Insurance studies suggest that Copaxone may prevent more flare-ups with a lower overall cost of care. The two drugs have different kinds of side effects, warnings, and precautions.

If you have questions about your current MS treatment plan, talk to your doctor. Each person’s MS symptoms and progression are different. Your doctor will be able to work with you to find the treatment that’s best for you.