Pharmaceutical Shenanigans

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One of the things that gets my dander up as a allergist is to see the repackaging of older medications which are then marketed as new and improved.  Companies try this tactic to gain new patents and extend the profitability of medications.  I’ve got nothing against companies making money and I’m fully aware that crass profit motives have driven some great discoveries in medicine.  These examples, however, are not great discoveries.

If you haven’t had much chemistry, a bit of background is helpful here.  Drug molecules often exist as stereoisomers.  This means that they have two different molecular structures which are mirror images of each other, just like your right and left hand.  In the body, only one of these molecules will bind to the target receptor and be active.  Imagine you just had one right handed glove.  Your right hand would fit easily, but your left hand would fit awkwardly or not at all.

Most drugs on the market exist as this mixture of right- and left-handed forms.  Now, companies have figured out how to isolate the active form.  This allows them to market the molecule as a brand new drug.  In reality, people had been taking the drug all along,  There’s generally nothing new or exciting about these single-isomer drugs except their branding campaigns.  Examples of this practice include, Clarinex(Claritin), Xyzal(Zyrtec), Xopenex(albuterol), and Nexium(Prilosec).  Note that all of these medications except albuterol are available OTC for significantly less than their prescription counterparts.

Other tactics include changing the delivery vehicle in a nasal spray (Astelin to Astepro) or gaining a new indication, say for once-daily dosing(Patanol to Pataday).

Generally, these new drugs are significantly more expensive than their older counterparts and their pharmacy co-pays are much higher.  To counteract this, the pharmaceutical companies often offer coupons for rebates and try to enlist us physicians in passing them out.  This tactic, in particular, irks me.  When doctors prescribe more expensive medications, we all pay indirectly.

Part of the job of being a physician is being a responsible steward of the medical dollar.  Because of this, I’m often quite blunt with my reps that if their drug offers no significant clinical benefit over older, cheaper medications, then I am very unlikely to prescribe it.

Dr. O

2 Comments

  1. I am currently taking Allegra generic. I have two questions.

    The first is whether the generic wears off sooner than it should because I find a sharp increase in my symptoms after about 12 hours. Certain times of the year, it is really a lot worse at night. I take the Allegra in the morning.

    My second question is whether Allegra is related to what used to be called Seldane. I could not take Seldane because it altered my mood over time. Someone told me that Allegra and Seldane are similar in that way.

    Thank you for having this place to ask questions!

    • In my experience, branded Allegra and its generic, fexofenadine, are effectively equivalent. The joke in allergy circles is that Allegra has always been a great 20 hour drug, but not a great 24 hour drug. Wearing off after 12 hours sounds more like worsening allergies as opposed to less effective medication. Also, allergies tend to flare at night, especially in peak seasons. One thing that will lower serum concentrations of fexofenadine is drinking lots of fruit juice, especially grapefruit juice.

      Seldane, or terfenadine, is a pro-drug. After it is absorbed, the liver converts most of it to fexofenadine, which is the active molecule. So if you took terfenadine, you effectively took fexofenadine as well. However, the molecular structure of fexofenadine is such that very little actually crosses the blood-brain barrier to enter the central nervous system. This is why it has essentially zero risk of sedation. Because it does not penetrate into the CNS, it should not have effects on mood. Of course, your mileage may vary.

      Hope this helps

      Dr. O

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