Cyclophosphamide (Cytoxan) is a chemotherapy drug and is the other second-line treatment for autoimmune encephalitis. Cyclophosphamide directly prevents T and B cells from multiplying, but it affects the ability of many other cells to multiply as well. For that reason, it has some potentially serious side effects including infertility, and instead rituximab is usually the preferred second-line therapy prior to the use of cyclophosphamide.

A person who has Autoimmune Encephalitis has antibodies attacking their brain cells. Some autoantibodies attack the surface of the brain cells others are able to get inside the cell it is attacking. Cyclophosphamide tries to control the autoantibodies from attacking inside the brain cells.

Intracellular antibodies (those that are INSIDE the cell and involve aggressive T-cell responses targeting the neuronal brain cells) are mostly mediated by cytotoxic CD8+ T cells that cause functional and structural neuronal damage and this is why there is a likelihood that a response to immunotherapy is not seen in these patients.Cyclophosphamide can cross the blood brain barrier and directly affect the T cells and how they change when you have paraneoplastic AE, vs Rituxan which can reduce B cell production. Cyclophosphamide is a chemotherapy therefore a cell killing drug, caution is taken with its use because it can cause infertility.

Selfcare while on Cytoxan/Cyclophosphamide Treatment

· Drink at least two to three quarts of fluid every 24 hours, unless instructed otherwise

· It is important to void (empty your bladder) frequently especially in the first 24 hours after taking Cytoxan. Report any pain or burning on urination to your health care provider.

· You may be at risk of infection so try to avoid crowds or people with colds, and report fever or any other signs of infection immediately to your health care provider.

· Wash your hands often.

· To help treat/prevent mouth sores, use a soft toothbrush, and rinse three times a day with one teaspoon of baking soda mixed with 8 ounces of water.

· Use and electric razor and a soft toothbrush to minimize bleeding.

· Avoid contact sports or activities that could cause injury.

· To reduce nausea, take anti-nausea medication as prescribed by your doctor, and eat small, frequent meals.

· Avoid sun exposure. Wear SPF 15 (or higher) sunblock and protective clothing.

· In general, drinking alcoholic beverages should be kep0t to a minimum or avoided completely. You should discuss this with your doctor.

· Get plenty of rest.

· Maintain good nutrition.

· If you experience symptoms or side effects, be sure to discuss them with your health care team. They can prescribe medication and/or off suggestions that are effective in managing such problem.

Side effects of Cytoxan/Cyclophosphamide

· Nausea

· Vomiting

· Loss of appetite

· Stomach ache

· Diarrhea

· Darkening of skin or nails