Sherry,
The clinical trials of Tykerb used that combination and the FDA will only grant approvals based on that particular trial.
But, now that it is approved by the FDA, any oncologist can prescribe it as he sees fit through a process called "off label". I found this on the internet:
"Off-label use is the practice of prescribing
drugs for a purpose outside the scope of the drug's approved label, most often concerning the drug's
indication. In the
United States, the
Food and Drug Administration (FDA) requires numerous clinical trials to prove a drug's safety and efficacy in treating a given disease or condition. If satisfied that the drug is safe and effective, the drug's manufacturer and the FDA agree on specific language describing dosage, route and other information to be included on the drug's label. More detail is included in the drug's package insert. However, once the FDA approves a drug for prescription use, they do not attempt to regulate the practice of medicine, and so the
physician makes decisions based on her or his best judgment. It is entirely legal in the United States and in many other countries to use drugs off-label. Exceptions to this are certain
controlled substances, such as
opiates, which cannot be legally prescribed except for approved purposes (at least in the U.S.). In
Australia,
amphetamines are included in these drugs which cannot be prescribed off-label.
Some drugs are used more frequently off-label than for their original, FDA-approved
indications. A
1991 study by the U.S.
General Accounting Office found that one-third of all drug administrations to
cancer patients were off label and more than half of cancer patients received at least one drug for an off-label indication<SUP class="noprint Template-Fact">
[citation needed]</SUP>. Frequently the standard of care for a particular type or stage of cancer involves the off-label use of one or more drugs. An example is the use of
tricyclic antidepressants to treat
neuropathic pain. This old class of
antidepressants is now rarely used for
clinical depression due to
side effects, but the tricyclics are often effective for treating pain."
Hugs
Christine