Natural Products as Drugs - Biotechnology and Your Health: Pharmaceutical Applications - page 26

FDA Approval of New Drugs
In many countries, including the United States, drugs are only available if a govern-
ment agency has determined that they are safe and effective. In the United States,
the Food and Drug Administration ( FDA ) is responsible for approving drugs for sale.
The FDA decides whether to approve a drug based on a large amount of information
from laboratory, animal, and human studies. Laboratory studies with cells, as well as
animal studies, provide clues as to the drug's potential usefulness and possible toxic
effects. Human studies, sometimes called clinical trials, may begin only after the
FDA has reviewed all the laboratory and animal studies. Clinical trials are done in
three phases. Studies in Phase 1, generally performed on a small number of healthy
volunteers, are designed to show how the body takes up and eliminates the drug, and
to find out what toxic effects the drug might have in humans. In Phase 1, the drug
is given in increasing doses, starting with a very low dose identified to be very
unlikely to be toxic in humans from the results of the animal safety studies. Phase
2 studies, performed with a small number of people who have the condition the drug
is intended to treat, compare the new drug to a standard drug for the condition or, if
there is no approved drug for this condition, to a placebo —an inert substance such
as a sugar pill. Phase 2 trials, which are the first human tests of whether the drug
will benefit patients, are often double-blind tests , meaning that neither the subjects
nor the physician researchers measuring the drug's effects know who is getting the
new drug and who is getting the control drug, whether approved drug or placebo.
Phase 3 trials, also blind and controlled, are generally larger and performed at
several different medical centers. The results of all the clinical trials are analyzed
using mathematical methods to see if the studies support the usefulness of the drug.
During the entire clinical testing period, data are collected on any harmful effects
and these results must be reported to the FDA. The pharmaceutical company must
also demonstrate that it can manufacture the drug at a consistently high level of
purity and that the drug can be stored without breaking down. FDA scientists,
sometimes with advice from outside medical experts, review all the information and,
based upon these reviews, the FDA decides whether the results support the safety
and efficacy of the new drug. Only if the results are positive may a company offer
the drug for sale. Information on any harmful effects of the drug will continue to be
collected by the company and reported to the FDA. If necessary, this information will
be provided to physicians to help them prescribe the drug safely. Severely harmful
effects that outweigh the potential benefit of the drug may eventually cause the drug
to be withdrawn from the market.