Rituximab (Rituxan and MabThera)

Rituximab is given as an intravenous infusion (IV or “drip”) into a vein. The infusion usually takes two - four hours, although occasionally it can take longer. A course of rituximab for rheumatoid arthritis usually consists of two 1000mg doses given 15 days apart. To treat vasculitis, a smaller dose is given once a week for four weeks in a row.

The effects of rituximab begin about six weeks after the infusions. Usually by the third month the full effect occurs, and can last up to nine months.

Sometimes, patients’ blood pressure can drop during the treatment. Those who take medication to lower their blood pressure may have to stop it before the infusion.

Some patients feel mild side effects during or up to 24 hours after receiving rituximab. These usually occur with the first infusion, and can include mild throat tightening, flu-like symptoms, rash, itchiness, dizziness, back pain, nausea, upset stomach, sweating, nervousness, muscle stiffness, and numbness. These symptoms can be reduced by receiving a steroid injection before the infusion, along with acetaminophen (Tylenol) and diphenhydramine (Benadryl). The infusion is sometimes stopped for a short while and then restarted at a slower rate if the symptoms get better. Rarely, patients will have more serious symptoms, such as wheezing, mouth or throat swelling, trouble breathing, or chest pain. Patients who experience these symptoms should tell their health care providers immediately; patients may receive stronger medications to treat those symptoms.

In the months after the treatment, some people may notice more frequent infections, such as colds or sinusitis. Usually, these are not severe. There are a few rare but serious side effects from rituximab. These include severe skin reactions and mouth sores. Patients who experience vision changes, loss of balance, difficulty walking, or confusion should contact their doctors immediately.

Combining treatment with other biologic drugs, which suppress the immune system, including etanercept (Enbrel), adalimumab (Humira), infliximab (Remicade), certolizumab (Cimzia), golimumab (Simponi), abatacept (Orencia), and tocilizumab (Actemra) may increase the risk of serious infections and medication side effects. Blood pressure medications may increase the risk of low blood pressure during the infusion.

Tell your doctor if you have lung or heart problems, or have ever had any major infections (especially hepatitis). Let your health care providers know about all medications you are currently taking, including over-the-counter medications, supplements, and herbal therapies. Also, tell them about all allergic reactions you have had to medications. If you are a woman who can get pregnant, it is important to use reliable birth control before treatment and for 12 months afterward. Since vaccines are not as effective for several months after receiving rituximab, you should ideally receive necessary ones before starting treatment or between courses.