Generic Drugs
New or brand name drugs are
protected in the United States by patent for 20 years. After the patent expires other companies can
market the drug. These generic drugs may
be identical chemically, and they may or may not be equivalent therapeutically
to the original drug. They will have
different binders, fillers, and dyes.
Sometimes when a brand goes off patent the company may withdraw the
original drug from the marketplace and begin making the same drug in a
different form. They may produce a
tablet instead of a capsule. Tablets and
capsules have different bioavailability to the body and many times one cannot
be substituted for the other. The body may
not absorb the drug/generic as well or a rapidly.
Many generic drugs are just as
effective as the proprietary (brand name) drug.
Biochemical individuality of the patient can cause a wide variance in
drug processing by the body. Doctors
write prescriptions for the generic drugs because they are generally
cheaper. Some insurance companies will
not pay for a brand name or proprietary drug if a generic is available. In these cases the doctor must specify that
the proprietary drug is a medical necessity, which is written as “dispense as
written” on the prescription.
The FDA rates generics as A – an
exact equivalent or B-if the bioavailability profile is different. Pharmacists are usually the only ones who
know the rating for a generic. When
switching from a brand drug to a generic, some patients may be able to tell a
difference. In most cases the body will
adjust to a generic drug with ease. For
serious diseases a patient may want to check with the doctor or pharmacist
before switching to a generic.