Which of the following is a common side effect of interferon beta-1a (Avonex)?

Flu-like symptoms are recognized as a common side effect of interferon beta-1a (Avonex). This medication is often associated with these symptoms due to its immunomodulatory effects, which can provoke an immune response in the body. Patients typically report symptoms such as fatigue, fever, chills, muscle aches, and malaise shortly after administration, especially with initial doses or when dosages are increased. These flu-like symptoms usually subside with continued treatment and can often be mitigated by premedication strategies, such as taking analgesics or antipyretics before injecting the medication.

Other options, while they may present in various clinical contexts or with other medications, are not typical side effects associated specifically with this treatment.