Drugs That Cause Amenorrhea, or Missed Periods

For most women, secondary amenorrhea, or period loss, is caused by excessive dieting, exercise or changes in weight. Some drugs can also cause women to lose their periods, however, including chemotherapy drugs, contraceptives or drugs used to treat cancer.

Contraceptives
Drugs used to prevent pregnancy, called hormonal contraceptives, can disrupt a woman's menstrual cycle. Medroxyprogesterone, or Depo-Provera, is more likely to cause this condition. According to A.D.A.M., its effects can even last months after a woman stops taking the drug. Other contraceptives that increase your amenorrhea risk: Levonorgestrel and some oral contraceptives.

Phenothiazines
These drugs are used to treat many conditions, the most common including schizophrenia, other mental disorders and severe nausea and vomiting. Phenothiazines can elevate prolactin levels while causing amenorrhea. The Advanced Fertility Center of Chicago notes that it may also cause galactorrhea, or breast milk leakage not caused by pregnancy or nursing.

Drugs Affecting Dopamine
In general, links have been drawn between dopamine-affecting drugs and amenorrhea according to the Merck Manual. Anyone who takes drugs that affect dopamine are at a higher risk for missed periods. Some drugs that affect dopamine include:

- Antihypertensives, such as reserpine and verapamil.
- Drugs used to treat gastrointestinal (GI) conditions, such as cimetidine.
- Opoids, such as morphine and codeine.
- Tricylic antidepressants, such as clomipramine.
- Antipsychotic drugs, such as risperidone and olanzapine.

Illegal drugs, such as cocaine, can also affect a woman's menstrual cycle.

Busulfan
Called an alkylating agent, busulfan is used to slow down the reproduction of certain white blood cells, which helps prepare the body for a certain stem cell transplant. This is commonly administered to people with chronic myelogenous leukemia. Menstrual periods can cease while on busulfan, and there is the possibility it may cause infertility.

Chlorambucil
Also an alkylating agent, chlorambucil is used to treat certain cancers, such as chronic lymphocytic leukemia, non-Hodgkin's lymphoma or Hodgkin's disease. It works by reducing blood cells in bone marrow. It may cause amenorrhea, which should be reported to a doctor immediately. Other serious side effects include yellowing of the eyes or skin, red urine and black stools.

Cyclophosphamide
This drug, also used to treat several cancers, helps minimize the spread of some types of cancer cells. Infertility has been associated with it; amenorrhea is a common side effect of this drug. In general, many drugs used to treat cancer may cause amenorrhea, and in some cases, cause temporary or permanent infertility.

Sources:
A.D.A.M.
The Advanced Fertility Center of Chicago
Merck Manual