Ellen Campbell -Grizzle - PHARMACY TODAY THE DEBATE surrounding brand name and generic drugs is raging. People want to know if a generic drug, usually 30 per cent to 50 per cent less expensive than the brand, is as good and as safe. The answer lies in understanding the similarities and differences between them.
Most drugs have three names - a chemical name, a generic name and a brand name. For example, we recognise the brand name Valium, the generic name diazepam but few persons know the chemical name 7-chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one. The chemical names are usually too long and complicated so manufacturers give a standard generic name and identify their own version by a brand name. Some manufacturers of brand name drugs also manufacture generics.
When a new chemical entity is developed, the innovator company applies for a patent that usually lasts for about 17 years. Ten years may be taken up with tests and clinical trials before the drug may be approved for sale. During the rest of the patent life, the manufacturer will attempt to recover the hundreds of millions of dollars invested as well as make a profit. Once the patent expires, generic manufacturers copy the formula without the cost of research and development. This means that generic drugs are usually less expensive.
Generic drugs contain the same active ingredient, strength and dosage form as the brand name drug. They may differ in colour and other non-active ingredients such as fillers, binders and dyes that give the product its appearance or mask its taste. These differences can change the bioavailability of the drug (that is, the rate and extent at which the body absorbs the drug).
Regulatory agencies require that bioavailability falls within plus or minus 30 per cent. This means that your generic medication may be absorbed by your body up to 30 per cent faster or slower than the brand name drug. In some cases this variation can affect the outcome of
therapy.
BRAND NAME
Therefore, there are times when your doctor will insist on a brand name drug, for example, if the drug has a Narrow Therapeutic Index (NTI), the slightest variation in bioavailability can cause serious side effects or loss of effectiveness. Also, individual patient factors can affect this choice. In such cases, in Jamaica, the physician must write on the prescription "Do not substitute".
There are several generic versions being sold and you should know that switching generics has draw backs. One week you can take a generic that is absorbed 20 per cent faster, and the next week one that is absorbed 20 per cent slower. The end result may be a bioavailability variation of up to 40 per cent. For this reason, your pharmacy should provide you with the same generic medication on refills.
Also, where the physician does not insist on a brand name drug, the pharmacist is required by law to offer you the option of a less expensive generic drug that is bioequivalent (with acceptable bioavailability when compared to the brand name drug).
There is no doubt that generics offer a wallet saving choice. Brand name drugs are important because they are the result of constant innovation in the search for better medicines to treat illnesses. These new drugs provide the templates for the generic manufacturers to copy. Generics are not always identical twins of their brand name counterpart and not all brand name drugs have generic equivalents. It's up to you, your physician and pharmacist to make sure that you get the most effective drug at the best price. If you have any doubts at all, ask your pharmacist, you have the right to know!
Ellen Campbell Grizzle, President,
The Caribbean Association of Pharmacists; Director, Information & Research at the National Council on Drug Abuse,
Kingston, Jamaica.
