Cytoxan is a prescription drug approved by the U.S. Food and Drug Administration (FDA) to treat cancer. Cytoxan is sometimes prescribed off-label to treat rheumatoid arthritis. Cytoxan is also referred to by its drug name, cyclophosphamide.
Cytoxan is an immunosuppressant, or in other words, a drug that suppresses the immune system. Cytoxan is also considered a disease-modifying anti-rheumatic drug (DMARD). Cytoxan is believed to work by preventing the production of deoxyribonucleic acid (DNA) in certain cells, including cells of the immune system. Blocking DNA production causes those cells to die, thereby suppressing the immune system and weakening autoimmune attacks.
Cytoxan is not appropriate for pregnant women or women who plan to become pregnant within a year of using it. Cytoxan is not recommended for people who have urinary outflow obstruction. Cytoxan may not be appropriate for those who have blood disorders, liver problems, or infections. Cytoxan should be used with care in elderly people and those with increased risk for heart problems.
How do I take it?
Prescribing information states that Cytoxan can be administered as an intravenous infusion (slow injection into your vein) by a health care professional or taken orally as a tablet once daily.
It is important for both men and women to use effective birth control while taking Cytoxan and for at least a year after they stop taking the drug.
The FDA-approved label for Cytoxan lists common side effects including low white blood cell counts, fever, hair loss, nausea, vomiting, and diarrhea.
Rare but serious side effects listed for Cytoxan include severe infections, bone marrow failure, urinary tract and kidney damage, heart conditions including irregular heartbeat and heart failure, lung damage that can lead to respiratory failure, liver damage that can lead to death, and fetal harm.
Seek medical help immediately if you experience trouble breathing, irregular heartbeat, or pain in your chest, jaw, left arm, or abdomen while taking Cytoxan. Inform your doctor right away if you notice abdominal pain, black or bloody stools, sudden weight changes, significant decrease in urine output, or changes to your menstrual cycle.
Taking Cytoxan lowers your resistance to infection. Wash your hands frequently and avoid exposure to people who are ill or have recently been ill with a cold or flu. Consult your doctor before receiving vaccinations while taking Cytoxan. Inform your doctor if you develop signs of infection such as fever, chills, or sore throat.
For more details about this treatment, visit:
Cyclophosphamide (Oral Route, Intravenous Route) — Mayo Clinic
Cyclophosphamide (Cytoxan) — American College of Rheumatology