Avonex Side Effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.
Serious side effects: Get medical help.
Serious allergic reactions: If the patient gets any of these: Swelling of the face, lips or tongue; Difficulty breathing; A rash.
Call a doctor immediately. Do not use any more Avonex until the patient has spoken to a doctor.
Depression: If the patient gets any symptoms of depression: Feeling unusually sad, anxious or worthless.
Call a doctor immediately.
Liver problems: If the patient gets any of these symptoms: Yellowing of the skin or the whites of the eyes (jaundice); Itching all over; Feeling sick, being sick (nausea and vomiting); Easy bruising of the skin.
Call a doctor immediately as they may be signs of a possible liver problem.
Side effects seen in clinical trials: These are the side effects that people reported when Avonex was being tested. The figures are based on how many people said they had them. It gives an idea how likely the patient is to get similar side effects.
Very common side effects (may affect more than 1 in 10 people): Flu-like symptoms - headache, muscle aches, chills or a fever: see Flu-like symptoms as follows; Headache.
Common side effects (may affect up to 1 in 10 people): Loss of appetite; Feeling weak and tired; Difficulty sleeping; Depression; Flushing; Runny nose; Diarrhoea (loose stools); Feeling or being sick (nausea or vomiting); Numbness or tingling of skin; Rash, bruising of the skin; Increased sweating, night sweats; Pain in the muscles, joints, arms, legs or neck; Muscle cramps, stiffness in the joints and muscles; Pain, bruising and redness at the injection site; Changes to blood tests- Symptoms the patient might notice are tiredness, repeated infection, unexplained bruising or bleeding.
Uncommon side effects (may affect up to 1 in 100 people): Hair loss; Changes to the monthly period; Burning feeling at the site of injection.
Rare side effects (may affect up to 1 in 1,000 people): Difficulty breathing; Kidney problems including scarring that may reduce the kidney function.
If the patient gets some or all of these symptoms: Foamy urine; Fatigue; Swelling, particularly in the ankles and eyelids, and weight gain. Tell the doctor as they may be signs of a possible kidney problem.
Blood clots in the small blood vessels that can affect the kidneys (thrombotic thrombocytopenic purpura or haemolytic uremic syndrome). Symptoms may include increased bruising, bleeding, fever, extreme weakness, headache, dizziness or light-headedness. The doctor may find changes in the blood and the function of the kidneys.
If any of the effects trouble the patient, talk to the doctor.
Other side effects: These effects have been seen in people using Avonex, but the likelihood of occurrence is not certain.
An underactive or overactive thyroid.
Nervousness or anxiety, emotional instability, irrational thoughts or hallucinations (seeing or hearing things that are not real), confusion or suicide.
Numbness, dizziness, seizures or fits and migraines.
An awareness of the heartbeat (palpitations), a rapid or irregular heartbeat, or heart problems which would have the following symptoms: a reduced ability to exercise, inability to lie flat in bed, shortness of breath or swollen ankles.
Liver problems as described previously.
Nettle rash or blister-like rash, itching, worsening of psoriasis, if the patient has it.
Swelling or bleeding at the site of injection, or chest pain after an injection.
Gaining or losing weight.
Changes to test results, including changes to liver function tests.
Pulmonary arterial hypertension: A disease of severe narrowing of the blood vessels in the lungs resulting in high blood pressure in the blood vessels that carry blood from the heart to the lungs. Pulmonary arterial hypertension has been seen at various time points during treatment, including several years after starting treatment with interferon beta-products.
If any of the effects trouble the patient, talk to the doctor.
Effects of the injection: Feeling faint: The first injection of Avonex may be given by the doctor. It may make the patient feel faint. He/she may even actually faint. This is unlikely to happen again.
Just after an injection, the muscles may feel tense or very weak - as though having a relapse. This is rare. It only happens when the patient injects and the effects soon pass. They may happen any time after starting on Avonex.
If the patient notices any irritation or skin problems after an injection, talk to the doctor.
Flu-like symptoms: Some people find that after using Avonex Pen, they feel like they have flu. Signs are: Headache, Muscle aches, Chills or a fever.
These symptoms are not really flu. The patient can't pass it on to anyone else. They are more common when he/she first starts using Avonex. As the patient keeps using the injections, the flu-like symptoms gradually decrease.
Three simple ways to help reduce the impact of flu-like symptoms: Use Avonex Pen injection just before bedtime. This may allow the patient to sleep through the effects.
Take paracetamol or ibuprofen half an hour before Avonex Pen injection and continue taking it for up to a day. Speak to the doctor or pharmacist about a suitable dose.
If the patient has a fever, drink plenty of water to keep hydrated.
Reporting of side effects: If the patient gets any side effects, talk to the doctor or pharmacist. This includes any possible side effects not listed. By reporting side effects, it can help provide more information on the safety of this medicine.