Experts in endocrinology share their insights into the clinical practicalities of the different types and formulations of levothyroxine treatment in patients with hypothyroidism.
Antonio Bianco, MD, PhD: In practical terms, I have patients where I’ll look at their TSH [thyrotropin levels], let’s say TSH is 3.5, and I’ll tell them that once per week, they should take a half tablet more. If on Sunday, they decide to take a half tablet more, it’s only a minor change in the total dose that the patient is taking. It will bring their TSH down slightly, and some patients will feel better, and some will not. But I know there’s a possible placebo effect, even though I also know there are studies showing that minor changes in the dose of levothyroxine should not affect clinical outcomes, but anecdotally, that’s what we see in the office; minor adjustments in the dose sometimes do make a difference with the patients. I believe that we should be aware of this minor change, and if this is something we can control, it’s something we should do for our patients.
James Hennessey, MD, FACP: Also in the study [conducted by Juan Pablo Brito Campana, MBBS], they had a subgroup of study participants that was taking more than 100 mcg a day—about364 mcg—and interestingly, they were able to maintain a normal TSH on the same insistent brand about 71% of the time. That indicates that there’s some variability in TSH outcomes that we’ll see at baseline throughout our practice. The interesting thing here was, if the patients were switched to another generic, they would maintain a normal TSH 76.6% of the time. Why would switching be an improvement? We can move on from there. What you were saying before about switching from brand names to generics is completely valid, because Juan Pablo was very clear in stating that the study did not address any changes from brand names to generics. It referred specifically to the 3 generics that had been referenced to that particular thyroxine product.
Transcript edited for clarity