• Avonex is a brand (trade) name for interferon beta-1a which may be used to treat certain types of multiple sclerosis (MS) in adults.
• Avonex is a type of interferon. Interferons are a group of proteins that are produced naturally by the body in response to viral infections. Interferon beta-1a, the active ingredient in Avonex is, a 186 amino acid glycoprotein. Although the interferon in Avonex is man-made, it contains all of the same basic components as the interferon beta that occurs naturally in the human body. Interferons help control immune system activities. Interferons also “interfere” with viral replication by protecting cells from viral infections.
• Experts aren’t sure exactly how Avonex works for MS but believe it helps control immune system activities, preventing the immune system from attacking the myelin sheath. Avonex helps to inhibit inflammation that can cause MS flare-ups. Avonex may also help slow the progression of physical disability associated with MS and reduce the number of relapses.
• Avonex contains standard interferon beta-1a for intramuscular injection that has a limited length of activity in the body. This means it needs to be injected every week.
• Avonex belongs to the class of medicines known as interferons.

• May be used to treat relapsing forms of multiple sclerosis in adults. This includes clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease.
• Administered by intramuscular (IM) injection once every week (7 days). People can be taught how to self-administer Avonex.
• Although Avonex does not cure MS it helps reduce the symptoms of MS and decrease the number of relapses.
• Avonex is available as a prefilled autoinjector and prefilled syringe each containing 30 micrograms of interferon beta-1a in 0.5mL. After an initial dose titration over 3 weeks, the recommended dosage is 30 micrograms once a week.
• The Avonex pen is designed for self-administration into the upper outer thigh. Self-administration is straightforward, but it is best to get a healthcare professional to demonstrate it initially.
• A starter kit (called AvoStartGrip Titration Kit) contains three devices coded white, yellow, and purple that fit onto the usual Avonex prefilled syringes to stop them from injecting a full dose for the first 3 weeks. This allows your body time to get used to Avonex and reduces the risk of flu-like symptoms that may occur if you start Avonex at a full dose of 30mg. The white device is used for the initial injection (week 1) and gives you 1/4 of a dose of Avonex. The yellow device is used for week 2 and gives you 1/2 of a dose of Avonex. The purple device is used for week 3 and it gives you 3/4 of a dose of Avonex. From then on you can use the Avonex prefilled syringes or autoinjector without the device.
• Avonex should be administered into the upper thigh and injection sites may be rotated between the left and right thighs.
• IM administration results in fewer injection site reactions than SC administration.

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

• Flu-like symptoms, such as chills, muscle aches and pains, weakness, or lack of energy were the most common side effects reported with Avonex in clinical trials. These occurred within hours or days of an injection, and resolved quickly in most people.
• Other common side effects include headache, pain, fever, chills, abdominal pain, and injection site pain. Depression, dizziness, nausea, muscle and joint pain, and infections (such as upper respiratory tract, sinus, urinary, or bronchial infections) are also common. Hair loss was reported in 4% of people prescribed Avonex compared to 2% taking a placebo.
• Anaphylaxis or other allergic reactions have occurred in Avonex-treated people. Immunogenicity and the presence of neutralizing antibodies were reported in 5% of people in clinical trials.
• Postmarketing surveys have also reported hemolytic anemia, heavy menstrual bleeding and abnormal bleeding between regular periods, rash, and cellulitis.
• Avonex suppresses the immune system and decreases the number of white blood cells in the body which may reduce a person's ability to fight infection. This ability will be further compromised if the person is also taking other drugs that suppress the immune system, such as chemotherapy agents, immune-modulating therapies, or other immunosuppressants. Plegridy may also lower platelet numbers which can increase the risk of bleeding or anemia.
• Should not be used by anyone with a history of hypersensitivity to natural or recombinant interferon beta-1a, or any other component of the formulation.
• Monitor those with pre-existing congestive heart failure for toxicity which has been reported alongside cardiomyopathy in postmarketing studies. Also, monitor for decreased blood counts. Seizures and the development of autoimmune disorders have been associated with the use of interferons.
• Hepatic injury has been reported rarely in people administered Avonex. Monitor patients for signs and symptoms of hepatic injury. Elevations in hepatic transaminases have been reported, which recurred when rechallenged. In some cases, there was concomitant use of other hepatotoxic drugs or alcohol.
• Requires regular blood test monitoring including CBC and differential WBC, platelets, and blood chemistries including liver and thyroid function tests.
• Cohort studies have not shown an increased risk of major birth defects associated with interferon products, including Avonex, although one small study found an increased risk of preterm birth.
• Store Avonex pens and prefilled syringes in a refrigerator between 36°F and 46°F (2°C to 8°C).
• No generic version of Avonex is available. Avonex is very similar to Rebif and they both have the same active ingredient (interferon beta-1a) but the way they are administered differs. Avonex is injected into your muscle (intramuscularly) once a week, but Rebif is injected 3 times a week under the skin (subcutaneously).

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

• Avonex is usually started at a low dose (7.5mg micrograms), and the dose is titrated up to 30 micrograms after 4 weeks.
• Do not attempt to self-administer the Avonex pen or syringe until your doctor, nurse, or other health care professional has taught you how to use it. Do not remove the cap off the Avonex pen or syringe until you are ready to inject it. If you do accidentally remove the cap of the pen, do not put it back on as this may cause the pen to lock.
• To use the Avonex pen, take the Avonex pen out of the refrigerator 30 minutes before you intend to administer it. Do not use hot water or a microwave to heat the pen, allow it to warm up naturally. Allowing the injection to warm to room temperature makes the injection procedure more comfortable for the person being administered it.
• Check its expiry date and do not use it if expired. Hold the Avonex pen with the white tamper-evident cap pointing upwards. With your other hand, grasp the cap and bend it at a 90° angle until it snaps off.
• Place the pen down on a surface while you remove the sterile foil from the needle cover. Pick up the pen and then press the needle onto the Avonex glass syringe tip. Gently turn the needle to the right until it is firmly attached. Hold the pen in one hand while with the other hand, hold onto the injector shield tightly and quickly pull onto the injector shield until the injector shield covers the needle all the way. This will cause the plastic needle cover to pop off.
• This will expose a small blue rectangular area next to the oval medicine display window. Check the contents of the syringe via the oval medicine display window. Do not use it if the liquid is cloudy, colored, or contains particles. A few air bubbles inside the pen are normal and do not affect the dose.
• Sit down. Choose an injection site on your outside, upper thigh, and wipe it with an alcohol swab. Let it dry and do not touch this site before administering the injection. Do not inject any areas of skin that are irritated, reddened, bruised, infected, or scarred. Place the Avonex pen on the injection site and hold the body of the pen at a 90° angle to the injection site. Make sure you can see the window. Keeping your fingers away from the blue activation button at the end of the syringe, press the syringe firmly down on the skin to release the safety lock. The blue rectangular area disappears when the safety lock has been released. While you maintain pressure against the skin of the thigh, press the blue activation button with your thumb. You should hear a click as the injection starts. Slowly count to ten. After you reach ten, remove the pen from the skin and apply pressure using a gauze pad. The circular display panel on the pen should now be yellow. This shows that a full dose has been given.
• You can replace the cover by lining up the exposed needle with the hole in the cover (do not use your hands) or just place the Avonex pen directly into a sharps bin without replacing the cover. Place all the other equipment associated with your dose in the sharps bin as well.
• Check the injection site after 2 hours for redness, swelling, or tenderness, and talk to your doctor if you have a reaction that does not clear up within a few days.
• Store Avonex prefilled syringes and autoinjectors at 2°C to 8°C (36°F to 46°F) in their original packaging to protect from light. They should not be frozen. Do not use Avonex if it has exceeded its expiry date. If refrigeration is unavailable, Avonex may be kept unrefrigerated, at room temperature (below 25°C (77°F) for 7 days. Do not put it back into the refrigerator after this time. Discard if unused. Avonex should not be exposed to high temperatures greater than 25°C (77°F). Do not use if Avonex has been kept at room temperature for longer than 7 days, or exposed to temperatures other than those recommended. Do not use it beyond the expiration date.
• Avonex is rarely associated with liver disease but you should monitor yourself and report any symptoms of liver disease (such as yellowing of the skin or eyes, abdominal pain or swelling, itchy skin, dark urine color, nausea or vomiting), shortness of breath, swelling of your lower limbs, easy bleeding or bruising, or changes in your mood to a doctor.
• If you experience an allergic reaction while self-administering Avonex seek urgent medical attention. Most people recover with antihistamines or corticosteroids. Talk to your doctor if you experience any other troublesome or worrying side effects from Avonex.
• Talk to your doctor about taking a prophylactic dose of acetaminophen or another pain-relieving/fever-lowering medication if you experience flu-like symptoms while prescribed Avonex.
• Although Avonex has not been associated with an increased risk of major birth defects you should tell your doctor if you are planning a pregnancy before conceiving or becoming pregnant while taking Avonex. There is no information on the risks associated with using Avonex during breastfeeding.

• Two large RCTs reported on the time to onset of sustained progression in disability in adults administered 30 micrograms of Avonex once a week. 35% of those assigned a placebo compared to 22% of those assigned Avonex had progression in their disability after 2 years of administering Avonex in study 1. This represented a 37% relative reduction in the risk of accumulating disability in the Avonex-treated group compared to the placebo-treated group. Avonex treatment also significantly reduced the frequency of exacerbations in those patients who completed 2 years. The annual exacerbation rate was 0.67 per year in the Avonex-treated group and 0.82 per year in the placebo-treated group.
• In Study 2, Avonex administration significantly delayed the time to development of a second exacerbation in an anatomically distinct region of the central nervous system (Kaplan-Meier estimates 39% in the placebo group and 21% in the Avonex group after 2 years). The relative rate of developing a second exacerbation with Avonex was 0.56 that of the placebo group (95% confidence interval 0.38 to 0.81).
• The safety and effectiveness of treatment with Avonex beyond 3 years is unknown.

Medicines that interact with Avonex may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with Avonex. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Avonex interacts with over 300 medications, but few of these interactions are considered major. Common medications that may interact with Avonex include:

• acetaminophen (risk of additive liver toxicity)
• antibiotics such as azithromycin, clavulanate, or erythromycin
• anticonvulsants such as Divalproex or fosphenytoin
• aspirin and NSAIDs such as diclofenac or ibuprofen
• bupropion
• cholesterol-lowering agents such as atorvastatin or simvastatin
• contrast agents such as iohexol or iopamidol
• dantrolene
• fingolimod
• heart medication ssuch as amiodarone, benazepril, or captopril
• herbals, such as black cohosh, comfrey, or ginkgo
• immunosuppressants such as azathioprine or cyclosporine
• isotretinoin
• ketoconazole or itraconazole
• leflunomide or terifluonide
• lomitapide
• methotrexate
• natalizumab
• niacin
• quinapril
• tamoxifen
• targeted therapies such as afatinib or alectinib
• tramadol
• vincristine
• zidovudine.

Note that this list is not all-inclusive and includes only common medications that may interact with Avonex. You should refer to the prescribing information for Avonex for a complete list of interactions.