Double-Blind Study

New drugs undergo double-blind testing to determine whether they are effective. The test is called double-blind because neither the doctor who is administering the medication nor the patient who is taking it knows whether the patient is getting the experimental drug or a neutral substitute, called a placebo.

Getting a new drug approved is a long, complex process in order to ensure the drug is safe and effective and does what the manufacturer says it will do. The testing is done to satisfy the United States Food and Drug Administration (FDA), the government bureau that administers laws affecting the purity and safety of food and drugs.

A new medication first undergoes testing to insure that it is safe for humans to consume, that is, nontoxic. The drug then is tested to make certain it is effective against a specific disease in humans. Early testing must have shown it was effective against a bacterium or virus in the test tube (in vitro testing), but conditions are different in the human body. After passing toxicity and efficacy testing, the drug is placed in a double-blind study to compare it to other drugs used for similar purposes.

Thousands of patients in medical centers throughout the nation are assigned to the experimental group, which receives the new drug, or the control group, which receives the placebo or other older medication. Neither the patient nor his or her doctor know which group the patient is in.

The patient receives medication as stipulated by the doctor. The placebos are made to resemble the new drug's appearance and taste to make it difficult to tell the difference. These studies may take years to complete, so that a sufficient number of patients can be analyzed.

A safety committee oversees the study and determines which group each patient is in. If they notice that many patients become ill with the new drug, they can stop the test. If the new drug is proving exceptionally effective, they can stop the test to allow the drug to be given to all patients.