Cytoxan and Lupus

A Drug With Serious Side Effects

Your healthcare provider may have prescribed you the immunosuppressant drug Cytoxan (cyclophosphamide) if your lupus has gotten severe. The "gold standard" drug regimen for treating severe lupus is Cytoxan in combination with the corticosteroid methylprednisolone.

Doctor explaining prescription medication to patient in clinic
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Cytoxan is actually a cancer drug, but in lupus patients, it's used to treat serious kidney inflammation (including lupus nephritis) or other complications that threaten the organs.

Cytoxan has serious side effects, including birth defects, so you'll want to learn more about it.

How Cytoxan Works

Cytoxan is used as a chemotherapy agent for cancers including lymphomas, myeloma, and leukemia. According to the American College of Rheumatology, it's also prescribed for severe, refractory rheumatoid arthritis or severe complications of lupus, myositis, scleroderma, or vasculitis.

Cytoxan is in a class of drugs known as alkylating agents. This means it slows or stops the growth of malignant cells or other rapidly dividing cells, such as white blood cells that attack your body during a lupus flare.

Immunosuppressants such as Cytoxan are used in the treatment of lupus for two main reasons:

  • They are potent drugs that help control disease activity in major organs.
  • They may reduce or eliminate the need for steroids.

Cytoxan is usually only given for three to six months until a patient goes into lupus remission. The drug is usually delivered intravenously, but it can be taken orally.

Taken orally, the dosage is based on your medical condition, weight, response to therapy and other treatments you may be receiving. Your healthcare provider will determine the correct dosage and regimen for you.

What Are the Side Effects of Cytoxan?

This drug has many side effects, so it should be closely monitored by your healthcare provider. The side effects include:

  • Thin, brittle hair
  • Darkened and thickened skin
  • Blistering skin or acne
  • Loss of appetite or weight
  • Fatigue
  • Cough
  • Congestion
  • Fever
  • Dizziness
  • Chills
  • Shortness of breath
  • Sort throat
  • Nausea
  • Vomiting
  • Pink/bloody urine
  • Mouth sores, blistering
  • Joint pain
  • Easy bruising/bleeding
  • Black/bloody stools
  • Severe stomach/abdominal pain
  • Swelling of the ankles/feet
  • Increased risk of shingles
  • Infertility

Talk to your healthcare provider right away if you experience any of the following while on Cytoxan:

  • Blood in your urine
  • Fever and chills
  • Easy bruising or bleeding
  • Shortness of breath
  • Swelling of the feet and ankles

You should also know that Cytoxan is carcinogenic. This means that it's associated with the development of some types of cancers, especially bladder cancer.

Before you start taking Cytoxan, be sure to tell your healthcare provider if you:

  • Are pregnant, or considering becoming pregnant
  • Are breastfeeding
  • Have ever had kidney disease
  • Are allergic to any drugs

An Alternative You Should Know About

A less toxic drug called mycophenolic acid has been shown to significantly reduce steroid dosage for patients with lupus nephritis or treatment-resistant lupus. It's considered first-line therapy for lupus nephritis and can often replace Cytoxan.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Parikh SV, Rovin BH. Current and Emerging Therapies for Lupus Nephritis. J Am Soc Nephrol. 2016;27(10):2929-2939. doi:10.1681/ASN.2016040415

  2. American College of Rheumatology. Cyclophosphamide (Cytoxan).

Additional Reading
  • Cyclophosphamide. MedlinePlus Drug Information. September 15, 2011.
  • Cyclophosphamide (Cytoxan). American College of Rheumatology. May 2015.
  • Glomerular Diseases. National Kidney and Urological Diseases Information Clearinghouse. NIH Publication No. 07–4358. April 2006.
  • Immune Suppressants. Lupus Foundation of America.

By Jeri Jewett-Tennant, MPH
Jeri Jewett-Tennant, MPH, is a medical writer and program development manager at the Center for Reducing Health Disparities.