MYTHS ABOUT GENERIC DRUG USE

[Guest guest]

In an article reprinted in the World Health Organization's Essential Drugs

Monitor in 1988, the FDA rebuts what it calls " 10 charges or myths

currently being raised, under the guise of independent dialogue, aimed at

discouraging health professionals from prescribing or dispensing generic

drugs " :

Myth 1: The 1984 action by Congress has eliminated safety and effectiveness

testing requirements for generic drugs and has thus reduced the confidence

that physicians and patients can have in the safety and effectiveness of

generic drugs.

Fact 1: What the law in fact does is eliminate the unnecessary requirement

for duplicative testing to redemonstrate the safety and effectiveness of

active drug ingredients that have already been shown to be safe and

effective by adequate and well-controlled studies and that have been widely

used and accepted by the medical community for many years.

Myth 2: FDA requires pioneer drug manufacturers to study their drugs in

thousands of patients, but it requires generic firms to test their drug

products in 20 or 30 healthy volunteers.

Fact 2: This statement is misleading. Testing in a large number of patients

is required for the pioneer drug in order to establish the safety and

effectiveness of the new active drug ingredient. Once this has been

established, the FDA need ensure only that others wanting to market a copy

of the innovator's product make their product correctly and that similar

amounts of the drug enter the bloodstream.

Myth 3: Plasma level studies (measuring the amount of a drug in the blood)

do not show how a drug acts at the site of action and therefore are not

indicative of how well a drug will perform.

Fact 3: Once the active ingredient is shown to enter the bloodstream at the

same rate and extent as the same active ingredient from another similar

drug product, there is no currently recognized scientific basis to allege

that the therapeutic effects or adverse effects of the two drugs will differ.

Myth 4: Bioequivalence studies (which measures the absorption of a drug

into the blood (drug products made by different companies having the same

absorption characteristics are called bioequivalent) are performed in

healthy volunteers, who are usually in their twenties. However, many of the

drugs are used primarily in elderly patients. These elderly patients can be

expected to absorb and metabolize the drug differently than do the healthy

volunteers. Therefore bioequivalence testing is not an indicator of how the

drug will perform in patients.

Fact 4: The testing in healthy volunteers, which shows an equivalent blood

level between the generic and the brand name product, is a strong indicator

that the two tested dosage forms will behave the same under the same

conditions. No one has demonstrated that two products found by conventional

tests to be bioequivalent perform in equivalently in different patients. It

is also preferable to subject healthy people, rather than already weakened

or disabled patients, to the blood sampling and other discomforts of

bioequivalence testing.

Myth 5: The FDA applies lower standards for generic approval compared to

those required for the brand name products.

Fact 5: The lesser standard that is usually implied in such a statement

relates to the safety and efficacy testing mentioned earlier. FDA in fact

requires that the manufacturers in both instances follow good manufacturing

practice, that they show that their drug is stable, that it is

bioequivalent, and that it meets the same standards of identity, strength,

quality and purity.

Myth 6: The FDA has no written rules or criteria for how it determines

bioequivalence.

Fact 6: The FDA has required generic drugs to be bioequivalent to brand

name products since the mid-1970s, and it published final regulations on

bioequivalence in January 1977.

Myth 7: Because the FDA allows a variation of + 20 or 30% in the blood

levels between the brand name and the generic products, generics may differ

by as much as 60% from each other.

Fact 7: The test that the FDA employs and the standard that is applied is a

statistical one. It is virtually impossible for a generic product to pass

if it in fact differs in its average plasma level by 20% from the standard

product. Deviations of more than 10% between generic and brand name

products are rare; usually the differences are much less than 10%.

Myth 8: Brand-name drugs are made in modern facilities, while generics are

often made in substandard facilities. Thus generics are of generally

inferior quality.

Fact 8: No one has been able to demonstrate that the quality of generic

drugs differs from that of the brand name counterparts. The rates of

defects found by the FDA in both brand name and generic products are

extremely low and speak well of the pharmaceutical industry's care in

producing prescription drugs. In fact, the innovator drug firms themselves

account for an estimated 70-80% of the generic drug market. Thus, to

believe generics are inferior, one would have to accept the premise that

the research-oriented drug firms can't adequately manufacture products

other than the ones they pioneered. It is also true that many innovator

drug firms distribute products made by smaller generic firms. It is

unlikely they would continue such arrangements if they really doubted the

ability of generic firms to manufacture quality products.

Myth 9: In calling drugs bioequivalent, the FDA overlooks documented cases

of bioinequivalence.

Fact 9: While there have been a few well-known, documented cases of

bioinequivalence, they are either examples from many years ago that have

long since been corrected or problems resulting from drugs which had never

gone through FDA's approval system. The FDA is not aware of a single

documented bioinequivalence involving any generic drug product that has

been approved by FDA as bioequivalent.

Myth 10: Patients using generic products are more likely to suffer adverse

reactions than those taking the brand name drug.

Fact 10: There is no evidence of a different rate of adverse drug reactions

(ADRs) between brand name products and their generic equivalents. There

have been some efforts recently by several brand name firms to stimulate

reporting to FDA's voluntary ADR system of adverse reactions to the

products of their generic competitors. The FDA has vigorously opposed any

such attempts.

The FDA has a public obligation to investigate thoroughly all allegations

of drug product defects or failures. The agency has not found any of the

allegations raised thus far in the brand name versus generic drug

controversy to be valid. FDA also has an obligation to make known to health

care professionals and to the public its conclusions that false or

misleading reports are being generated.

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