Do You REALLY Need Brand Synthroid?

You people are out there... spending $20 to $30 on brand Synthroid month after month: You're throwing your money away. It's your money to throw away, but you really don't need to do that! 

First a little history...

In 1986, Flint Laboratories, the then-manufacturer of Synthroid, contracted with a researcher at the University of California to conduct a study that they hoped would demonstrate that Synthroid was a better product than the major competitors' products. Unfortunately, when the study was completed in 1990, it clearly showed that all available brands of levothyroxine were, in fact, equal. 

In the intervening years, Flint Laboratories was sold to Boots Pharmaceuticals. When the researchers attempted to publish their results, Boots Pharmaceuticals exercised a clause in the contract that required their approval of the publication. The publication of the results of the study would have theoretically resulted in a switch to less expensive competitor products and a potential loss of the near monopoly Boots had on the thyroid replacement market. Boots Pharmaceuticals was sold to Knoll. Knoll persisted in their opposition to the publication of the study. 

Intervention on the part of the FDA finally broke the impasse. The manuscript was eventually published in 1997 in the Journal of the American Medical Association. With the publication came more than 60 class action suits alleging consumers had paid 2-3 times what they should have paid for levothyroxine as a result of the suppression of the University of California study from 1990 to 1997. Knoll eventually settled the case for $135 million.  LINK

So basically, the study says the generic IS just as effective as the brand.

Just recently, though, some researchers contend that it may be better to just switch to a natural thyroid product:

New Study Shows Natural Thyroid Better than Synthetic

Comparing Synthroid to Natural Thyroid: Their controlled study compared natural thyroid with Synthroid. What they found was that roughly half of the patients (48%) felt better on the natural thyroid, one-third had no preference, and one-fifth (18.6%) felt better on the Synthroid. Clearly the natural thyroid wins the comparison test (48.6% vs. 18.6%).


"At the end of the study, 34 patients (48.6%) preferred Desiccated (Natural Thyroid), 13 (18.6%) preferred Levothyroxine (T4), and 23 (32.9%) had no preference". LINK 

And yet, here's an ALTERNATIVE OPTION: 
All you really need to do is adjust the dose

Suppose for example, my high maintenance patient (let's call her Amy) has an open prescription for 88 mcg of Synthroid. Like a lot of my Goofmart Pharmacy patients, she insists on having brand Synthroid (despite the checkered past of the manufacturer). Amy's doctor wants to make her happy, so he prescribes it DISPENSE AS WRITTEN: Synthroid 88 mcg.

In case you didn't know, all the of the thyroid products come in different strengths. That's because thyroid medication has a "narrow therapeutic index." But what is a narrow therapeutic index?

A narrow Therapeutic Index is defined medically as the ratio between the average effective dose and the average lethal dose. It is an extremely close margin between an effective concentration of a therapeutic drug circulating in the blood and a fatal concentration. LINK

So a drug with a narrow therapeutic index has to be dosed carefully because it can go from being therapeutic to toxic very quickly depending on the patient and his/her needs.

In the past, patient Amy went to her doctor with symptoms of hypothyroidism. Her doctor ordered labs and the results indicated her thyroid function was low and suggested her getting a boost with thyroid medication. So the doctor put her on 88 mcg of Synthroid (based on her labs) and had her back in another 4-6 weeks to check the labs again. It's trial and error... with the error being on the low side of optimal to prevent toxicity. Doctors always start low and gradually increase... better to give too little than too much. We want therapeutic, not toxic.

But does Amy really need to have BRAND Synthroid? Given the history of trouble with the company, is that warranted? Given the suppressed study which shows that the generic is just as effective as the brand, why pay more? Given that the recent study of natural thyroid replacement (or as we call it in the pharmacy.. pig-throid) suggests the natural replacement is more effective, is brand (or generic) still warranted? That's something Amy needs to talk over with her doctor and her kitties.

And yet there is still a another option

Until there are more follow-up studies on natural (pig-throid) versus synthetic levothyroxine (brand Synthroid or generic levothyroxine), there will be those who insist on having BRAND Synthroid and doctors who will continue to prescribe it for them. But... really... is brand medically necessary?

Let's suppose that generic levothyroxine is not as potent as the brand Synthroid. That's not really true, but there's a lot of people who swear by it. Some people think the excipients affect absorption. Other people think the generic is less potent. I've heard all the stories.

Ok... let's pretend it is true... now what?

So let's say, for this example, that generic levothyroxine labeled as "100 mcg" is "therapeutically equivalent" to "88 mcg" of "the real stuff" -- brand Synthroid. (Let's further avoid the philosophical debate as to how a synthetic thyroid product, i.e. SYNTHroid manages to get called "the real stuff" -- that's another blog post entirely). 

Therefore, if 100 mcg of generic levothyroxine is equivalent to 88 mcg of Synthroid:

JUST GIVE THE PATIENT 100 mcg OF GENERIC LEVOTHYROXINE and SAVE THE PATIENT $240 A YEAR!


Run the labs! If the patient does well on 100 mcg of generic levothyroxine there would be no need to prescribe brand! Instead of focusing on brand versus generic, the prescriber should be concerned with how the patient is doing. TREAT THE PATIENT, NOT THE NUMBERS YOU WEASEL. It doesn't matter if the patient is on brand or generic if you're talking about potency. All that is needed is an adjustment in dose based on the labs of the patient. Meow, meow, meow!