Thalidomide

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Thalidomide, drug introduced in 1953, initially prescribed for its sedative properties and widely used by women to alleviate the nausea and vomiting common in the early stages of pregnancy. Thalidomide gained notoriety in 1961 when it was found to cause severe malformations in the growing fetus such as stunted development or the complete absence of limbs. More than 10,000 children were born with these disabling abnormalities before the drug was taken off the market. This disaster triggered more rigorous government regulations for drug testing. Today thalidomide is used in the treatment of leprosy, and experimentally in bone-marrow transplant patients and certain immune system disorders.

HISTORY

While its commercial distribution was halted, thalidomide continued to be used in experimental studies for a variety of diseases. A series of studies beginning in the mid-1960s showed that thalidomide was effective in treating a leprosy-related disorder, erythema nodosum leprosum (ENL). A serious skin disorder, ENL usually develops in leprosy patients after they begin taking antibiotics to combat the leprosy-causing bacterium Mycobacterium leprae. ENL is believed to be caused by an abnormal immune reaction to the killed bacteria.

The FDA approved thalidomide for the treatment of ENL in July 1998, at the same time placing unprecedented restrictions on the drug’s use. Under these restrictions, thalidomide can only be obtained from selected doctors and pharmacies that have agreed to follow a strict protocol designed to prevent birth defects from the drug. Both men and women taking the drug must use birth control during sexual intercourse, and women must also agree to undergo periodic pregnancy tests.

Thalidomide’s success in treating ENL, although not fully understood, triggered extensive studies into the drug’s effects on the immune system. Some studies suggest that thalidomide reduces the production of tumor necrosis factor-alpha (TNF-a), a protein made by immune cells that may cause problems such as wasting, or chronic weight loss, when produced in excessive amounts. Thalidomide has also been proven to heal painful canker sores in the mouth of patients with acquired immunodeficiency syndrome (AIDS) or other patients with impaired immune systems. Canker sores in these patients do not heal as readily as in people with normal immune systems, and the sores make eating difficult.

Early evidence suggests that thalidomide effectively suppresses the body’s rejection of donor bone marrow that sometimes occurs in bone-marrow transplant patients. Thalidomide is also being studied as a possible treatment for various cancers and other diseases because of its ability to inhibit growth of new blood vessels. This inhibition could slow or completely prevent growth of cancerous tumors that require new blood vessels in order to thrive.


RECENT USES

While its commercial distribution was halted, thalidomide continued to be used in experimental studies for a variety of diseases. A series of studies beginning in the mid-1960s showed that thalidomide was effective in treating a leprosy-related disorder, erythema nodosum leprosum (ENL). A serious skin disorder, ENL usually develops in leprosy patients after they begin taking antibiotics to combat the leprosy-causing bacterium Mycobacterium leprae. ENL is believed to be caused by an abnormal immune reaction to the killed bacteria.

The FDA approved thalidomide for the treatment of ENL in July 1998, at the same time placing unprecedented restrictions on the drug’s use. Under these restrictions, thalidomide can only be obtained from selected doctors and pharmacies that have agreed to follow a strict protocol designed to prevent birth defects from the drug. Both men and women taking the drug must use birth control during sexual intercourse, and women must also agree to undergo periodic pregnancy tests.

Thalidomide’s success in treating ENL, although not fully understood, triggered extensive studies into the drug’s effects on the immune system. Some studies suggest that thalidomide reduces the production of tumor necrosis factor-alpha (TNF-a), a protein made by immune cells that may cause problems such as wasting, or chronic weight loss, when produced in excessive amounts. Thalidomide has also been proven to heal painful canker sores in the mouth of patients with acquired immunodeficiency syndrome (AIDS) or other patients with impaired immune systems. Canker sores in these patients do not heal as readily as in people with normal immune systems, and the sores make eating difficult.

Early evidence suggests that thalidomide effectively suppresses the body’s rejection of donor bone marrow that sometimes occurs in bone-marrow transplant patients. Thalidomide is also being studied as a possible treatment for various cancers and other diseases because of its ability to inhibit growth of new blood vessels. This inhibition could slow or completely prevent growth of cancerous tumors that require new blood vessels in order to thrive.

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