Levamisole

Definition

Levamisole is used to treat colon cancer, specifically stage III colon cancer. Levamisole takes the full name of levamisole hydrochloride, and it is also known by the brand name Ergamisol.

Purpose

Levamisole is used to treat patients with stage III colon cancer after they have had surgery to remove the tumor, or as much of the tumor as possible. In stage III colon cancer, the cancer has spread to nearby lymph nodes. Levamisole is approved for use with fluorouracil (specifically, 5-fluorouracil), a drug that is thought to prevent cells from replicating, or making more of themselves, by interfering with the manufacture of the hereditary material the cells carry. The use of levamisole with fluorouracil makes it an adjuvant therapy, or one that when used in conjunction with another drug seems to increase the defenses of the patient.

Description

Levamisole was first made (by laboratory synthesis) in 1966, and since then it has been used in veterinary medicine to eliminate intestinal, or lower gut, parasites in domestic animals. It was found to be immunostimulant in 1972 and approved for use for colon cancer in 1990.

The drug seems to have a number of benefits for the patient. It increases the response of T cells, or cells belonging to the lymphatic system that can fight cancer cells. It also seems to increase the activity of cells that attack and destroy invading or cancer cells, including both monocytes and macrophages.

Because of the response levamisole brings from T cells, causing them to be more active, it falls into the category of drugs known as biological response modifiers.

Recommended dosage

The drug is given orally in tablet form. Tablets contain 50 milligrams of levamisole hydrochloride, and a standard dose is one tablet every eight hours for three days. Thereafter, the patient takes the same three-day course every two weeks for about a year.

Dosage must be adjusted according to the count of white blood cells and platelets in a patient's blood. In some cases, levamisole can be continued, even when fluorouracil must be stopped.

Precautions

The drug can cause changes in the composition of the blood, which can be fatal. For example, agranulocytosis, also known as neutropenia, may develop. The condition refers to a drop in a kind of white blood cells known as neutrophils that are important in the defense against bacteria and fungus. Thus, the patient becomes more likely to get a bacterial or fungal infection.

Side effects

Nausea and vomiting, diarrhea, hair loss (alopecia), and changes in the composition of the white blood cells, such as neutropenia, are among the most common side effects.

Interactions

Levamisole often interacts with alcohol in the same way that the drug disulfiram, which is used to discouragealcohol consumption in alcoholics (alcohol deterrent), does. The reaction is extremely unpleasant, and alcohol use is best avoided when levamisole is being taken.

The drug also interacts with warfarin, which is often given to heart patients to reduce the chance of blood clots forming. Levamisole can interfere with the action of warfarin, allowing blood clots to form; therefore, adjustments in the amount of warfarin heart patients take may be necessary if they are also taking levamisole.

Diane M. Calabrese

Adjuvant therapy

—Addition of a drug to another course of drug therapy to increase or enhance the immune response of a patient.

Macrophage

—Large cell-eating cell.

Monocyte

—A specialized type of white blood cell that attacks other cells, and acts as a phagocyte.

Neutrophil

—A specialized type of white blood cell that attacks other cells, and acts as a phagocyte.

Parasite

—An organism that lives by taking its nourishment from another organism.

Phagocyte

—Cell-eating cell.

T cell

—A cell in the lymphatic system that contributes to immunity by attacking foreign bodies, such as bacteria and viruses, directly.