O

off-label use Taking a DRUGfor a purpose other
than that for which it has received regulatory
approval. In the United States the Food and Drug
Administration (FDA) requires pharmaceutical
manufacturers to demonstrate the safety and effi-
cacy of a drug before approving it for use. Once a
drug receives FDA approval, however, doctors
may legally prescribe it for uses that are consistent
with current standards of care. The FDA does not
regulate how doctors prescribe or individuals take
approved drugs.
Additional beneficial effects of a drug often
emerge after the drug has been in use for some
time and doctors begin to notice those effects. For
some of these drugs the additional effects are so
significant that prescribing the drug for them sub-
sequently becomes an approved use. In other situ-
ations the drug becomes widely known for its
additional effects but the manufacturer does not
conduct further studies or seek FDA approval for
them.
Off-label use is most common when treating
conditions for which conventional therapies are
limited or unsuccessful, especially when the con-
dition is progressive or chronic such as MULTIPLE
SCLEROSIS, PARKINSON’S DISEASE, CANCER, and CHRONIC
PAINsyndromes. Doctors may also turn to off-label
use when prescribing medications for children
because many drugs receive approval without
having been tested for safety and EFFICACYin chil-
dren. A doctor’s decision to prescribe a drug off-
label draws from available clinical study results,
clinical observations, and best practices standards.
It is important for a person considering off-label
use of a drug to fully understand the potential
benefits and risks of such use as well as the drug’s
possible side effects and adverse reactions.

See also ADVERSE DRUG REACTION; INVESTIGATIONAL

NEW DRUG(IND); SIDE EFFECT.

Orange Book, TheA document the US Food and

Drug Administration (FDA) maintains that lists all

the drugs, prescription and over-the-counter, that

have FDA approval for use in the United States.

As of 2005 The Orange Book is available only as

an electronic document (www.fda.gov/cder/ob)

on the FDA’s Web site (print editions are no longer

obtainable). An individual may download the doc-

ument in a printable format to produce a paper

copy, if desired.

The FDA updates The Orange Bookdaily. These

updates provide, among other kinds of informa-

tion, the most current information about newly

approved generic products. The Orange Booklists

drugs by proprietary (trade or brand) name, active

ingredient, and patent holder. Listings identify the

INNOVATOR DRUG(first drug that received approval)

and any GENERIC DRUG also approved for use as

well as provide information about the status of the

product’s patent.

See alsoFORMULARY; INVESTIGATIONAL NEW DRUG.

orphan drug A DRUGto treat a rare condition.

The US Orphan Drug Act of 1983 (ODA) estab-

lished criteria in the United States to encourage

pharmaceutical manufacturers to investigate new

drugs and continue to produce approved drugs to

treat conditions, such as HUNTINGTON’S DISEASEand

some forms of MUSCULAR DYSTROPHY, that affect

fewer than 200,000 people. The underlying prem-

ise of an orphan drug is that its sales will not gen-

erate enough revenue for its manufacturer to

recover the costs of its development and testing, a

circumstance that makes research and production

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