There are certain risks associated with cyclophosphamide treatment you should be aware of. Providing your doctor with as much as possible information about your current health condition, past illnesses or impairments, any strange symptoms you experience, medicines you are currently taking, lifestyle and other important factors helps minimize the risks and achieve the best effect from treatment with cyclophosphamide.

Fertility problems:
Cyclophosphamide can cause infertility in both men and women, though this effect is reversible in most cases. Generally, infertility is observed in patients who continuously take increased doses of cyclophosphamide or in older patients. Women may develop temporary menstrual changes (stop having menstruations).

Pregnancy:
Taking cyclophosphamide while being pregnant  is very dangerous to an unborn child, it can cause serious birth defects.
Effective birth control methods should be used during the whole course of treatment with cyclophosphamide to prevent pregnancy. Even if a woman stops having menstruations she can still become pregnant. It is not advisable to father a child for men while taking cyclophosphamide. Breast-feeding while taking cyclophosphamide should also be discussed with the doctor.
Malignancies:
Even though cyclophosphamide  was invented to treat cancer, in rare cases there is a risk of developing a blood cancer such as leukemia or myelodysplasia or bladder cancer after taking cyclophosphamide.  This is referred to as a delayed side effect.
Infections:
Patients taking with cyclophosphamide should avoid exposure to infections because this treatment is associated with suppression of immune responses.
For patients with severely suppressed immune systems (for example, after after continuous treatment with higher doses) some infections may become fatal. That is why in case of bacterial, fungal, viral, protozoan, or helminthic infections cyclophosphamide treatment should be interrupted or the dose decreased. Discuss this with your doctor.

The benefit-to-risk issue of taking cyclophosphamide should be discussed with your doctor. Regular tests should be taken to monitor your health condition and the body’s response to the treatment with cyclophosphamide.