Most antiparkinsonian drugs have two names – a generic name (matching the international nonproprietary name) and a brand name. But is there a difference between them?
What are brand-name drugs?
A pharmaceutical company that owns a specific drug creates a brand (and trade name) for the drug. Two globally known brand names for the drug levodopa are Sinemet (production Merck Sharp и Dohme Limited) и Madopar (production Roche Products Limited).
If the company has a patent on this specific drug, they are the only ones who can sell it under that name after obtaining the drug license.
What are non-patented drugs?
After the patent expires (usually several years), other pharmaceutical companies are allowed to produce the same medication under its generic name (INN).
The chemical composition of the drug will be exactly the same as that of the branded drug because it contains the same active ingredient and is used in the same dose. For example, Madopar Roche available on the Russian market under the generic names levodopa/benserazide and benziel. A Sinemet available with us under the names Nakom, Tidomet Forte, Syndopa, Levodopa-Carbidopa. But only Roche has the license to sell as Madopar, и только Merck Sharp и Dohme Limited are licensed to sell Sinemet.
Generic drugs are tested to ensure they work the same and meet the same quality and safety standards as the brand-name version.
Patients often have to use a generic drug because they are as effective as the branded version but cost less. They are cheaper because the manufacturing company no longer spends on developing the active formula.
So, is there a difference?
Brand-name and generic drugs contain the same active ingredient. Sometimes inactive ingredients (known as “excipients”) may differ from those used in brand-name medications. These include sugar, flavorings, and colorings.
This means that a generic drug may look or feel different in shape, color, size, and texture compared to its branded equivalent. These differences will not affect how the medication works in your body—they are still the same because the active ingredient is what gives the drug its therapeutic effect.
However, the rate at which tablets or capsules dissolve and are absorbed into the bloodstream can sometimes vary between different brands. This can affect the concentration of the medication in the body – a very important point.
There is a concept called “therapeutic index” – it is the difference between the concentration level in the blood at which a drug has the intended effect and the level that is either too high (causes side effects or is toxic) or too low (ineffective).
The therapeutic index of certain medications may change as the disease progresses. Doses may become less effective or have more side effects. This can happen with both generic and brand-name drugs.
Thus, this is why it can be found that a specific medication suits a particular patient better than another. But predicting this in advance is almost impossible.
What to do if there is no suitable medication?
It is possible to substitute medications from one brand for another within the same international nonproprietary name. Be sure to maintain equivalent single and daily doses. Pay attention to any changes in symptoms and report them to your healthcare provider.
Good health to you!
Neurologist specializing in Parkinson’s disease at the V.S. Buzaev International Medical Centre, PhD, Gulnara Nailevna Akhmadeeva.
Doctor - Obstetrician-Gynecologist, Ultrasound Diagnostics Doctor