clinical trial is a specific kind of research
study that involves careful examination of the effects
of a drug (or other
treatment) administered to humans. Usually, some participants
are given the test drug while others are given an alternative
drug or a placebo;
no participant knows which kind of treatment he or she is
receiving. The researcher then determines whether the benefits
of the test drug are significantly greater than the alternative
drug or placebo.
For example, if a company has developed
a new compound which it feels will prevent migraines better
than an existing drug, or do just as well with fewer side
effects, it may organize a clinical trial of the new compound.
A group of migraine sufferers are recruited to participate,
and they may be paid for their time. Each participant is asked
to take a series of pills over a period of time -- without
knowing whether they have been given is the test compound
or the existing drug. During the study, each participant reports
when and if they experience migraine. If the participants
using the test compound report infrequent and mild headaches
while the participants using the existing drug complain about
frequent, severe migraines, then the researchers would conclude
that the test compound is effective and should be made available
for general medical use to treat and prevent migraines.
The goal of clinical trials is to determine
both the efficacy of the drug and also whether it has side
effects, toxicity and/or adverse interactions with other drugs.
The U.S. government has very strict standards for these studies,
and for how the results are to be evaluated, before a drug
is approved for use in the United States. Every year, many
compounds that are developed by pharmaceutical companies fail
clinical trials, meaning that they do not pass the high standards
for efficacy and safety, and never reach the market.
Article : "THE
Article : "ESTROGEN
Article : "PUTTING
GINGKO TO THE TEST"
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain