It's not as clear-cut as we'd like it to be. Many drugs on the market are generics to originator (branded) drugs. Do they differ? Can they be substituted? To simplify it, the answer is two fold.
Yes, because they are (bio) equivalent but no because sometimes they are metabolized differently and therefore the experience is that: they're not the "same"?!
Some pharmacists will tell you 'it's the same'! And quite rightly so, often when addressing patient fears, uncertainties and issues of treatment accuracy. It's a quick answer to calm the patient down. A generic drug contains the same active ingredient, at the same dose than it's original counterpart. Therefore in this light, they ARE the same!
However, when it comes to efficacy and side effect profile, generic drugs might differ. This is because formulations (processes of manufacturing the drug and excipients or other additives) can differ.
Potency may also differ, as drug concentrations, release rates and absorption into plasma rates also differ. The regulated ranges for plasma concentrations (AUC) usually fluctuate between 85-110% match. Meaning a generic drug can be less or more potent than the original drug even at the same dose. Generic drug bio-equivalence have to be the same by law, but bio-equivalence doesn't necessarily mean tolerance equivalence either.
Patients may often complain that one generic doesn't work for them, or that the generic "feels" different. Besides a strong possibility of them just being picky or playing mind games, there is a real rationale behind it. It might actually be that they metabolize the generic differently and hence experience (effect and side-effect of) the generic drug more or less than with the originator.
The other common patient phobia is with pricing. Many patients feel cheated if a drug is too cheap. They actually want to pay more as they think it will "work better". Again it often is a mind game associated with perceived value. But the truth is, big price difference are because of research setbacks.
The originator drug took time (including clinical trials) and lots money to develop, and so once it reaches the market for the first time, it benefits from patent exclusivity in sales. Usually 15-20 years. This is to recuperate the heavy research costs incurred and make profit for that manufacturing company.
After this period, the originator drug patent expires and is then made available to other manufacturers who can simply "copy" the 'recipe' for much less monetary investment and no research time. They therefore can slash the prices radically - hence cheaper generics.
At the end of the day, a generic drug will act in the same way as an original drug in effecting it's desired pharmacological effect. It may however feel different to a patient who experiences it differently due to a difference in overall metabolism.
Next time a patient asks you if "they're the same", what will you say?
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I fully agree. Concerta generic does really not work for me. I only found out now there is also a "clone" which I will try now. I have to take 2 of the generic 54mg to feel the difference as I used to with the original. And it influences my studies, my work, my life overall..I felt stupid when I thought maybe I am imagining it. But at 51 I know myself and tell you it is way different.....
ReplyDeleteThats very interesting to know and is congruent with the findings. Thank you for your reply.
DeleteThe clone has the best profile. It's a new formulation which improves absorption whether there is food in the stomach or not. I hope you've tried and adopted it. Take care xxx
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