Once you decide on combination therapy, what are the practical strategies—specifically, approved drug formulations, whether it be synthetic T3 (Cytomel) or DTE—that clinicians should consider at the front lines of care for hypothyroidism?
So you have a patient who has been on monotherapy, leave a thigh Roxon for a few months now and the patients are still asymptomatic and you identified that maybe they're not getting enough penetrates or they don't have enough circulating levels of T. Three. That's not being adequately monitored in the lab type, identify those patients. So you want to do that, you want to add T. Three. So how do you do it? Well, there's always in the conventional way that you'll see and certainly in the thyroid guidelines that are out there for anybody just to google. Is that your you can add a synthetic T. Three. They're generally short acting in leo thyroid nine which is side email and you can add that dose to your leaving Iraq. See I don't recommend that by the way in primary care it's a little dicey. You have to cut back, usually cut back your thigh, they leave out LT four dose by 25 micrograms. And then you can you start this other pill side of mail, you know, 2.5 to 7.5 mg. Usually requires multiple split doses during the day. Son of awkward, not a steady state, it's it's awkward to use. The other option is a synthetic combination, which is T four T three. In combination, it's synthetic. So you have living xeroxing and um almost like a thyroid together, it's combined. And that's leah tricks. And that's another option that's out there. And I've gotten other patients who've been on that. But there's one option that I would uh like deposit that's been around for a long time. That is also a combination thyroid T four T three medication that you may be familiar with. Certainly have heard about it and it's been around a long time. I'll tell you one thing, a lot of your patients have heard about it. In fact, there's been big names in the political crowd who Back about four years ago made news having been placed on a desiccated thyroid extracts. So people are talking about your patients are talking about, they're going to ask you about it. So I want to spend some time chatting about DT and I've been in this business a long time and a long time and I've used the T. E. In practice deliberate to patients. But you need to understand that Desiccated Thyroid x rays put around for about 130 years, probably longer than that. If you include china. It was first, I believe his first utilized in a patient in 1891 desiccated thyroid extract. It probably came from sheep back then. They used different animals. But then that patient was on it for 52 years, 52 years treated with desiccated thyroid extract. Now, that's all we had that was all available. And thank goodness we have that to help manage thyroid hormone replacement in the hypothyroidism placement. Otherwise a lot of people, it saved a lot of people from death and horrible morbidity is. So that was used for a long time. Understanding the way drugs and former therapy was in those days, the way the the drug is processed, it wasn't consistent in the The quality of the pale. There wasn't consistent doses of T 43 early on for a long long time. And people knew that was a problem. That's all they had. And I'm gonna tell you this helps understand a little bit of the biases and preferences biases. Pro and against use of DTs. And this is one of the biases against. There's people still remembering that you didn't have consistency of dozing in these products. It's not the case now. So, uh, synthetic. So we knew there was a problem with this. And so synthetics came out at about 1962. A surround I think is when they came out of the first synthetic. Leaving Iraq seen, uh, I didn't make a splash. People providers were comfortable in using DTs. I'm going to tell you there was a big push in the seventies. I'm just showing you how this is an amazing journey and why why we are and how we look and evaluate the use of DTs now. But in the 70s of big push remember headlines. Because I was working back then to get rid of all DTs, go to synthetic. That was the news in the headlines. But there was still uh resident hesitancy in actually using that by by providers and also by the patients. Then something happened in the 80s. That changed it all. And that is with the radio essay of TSH. Finally, there was a lab that was able to give you an indirect identification of the adequacy of circulating thyroid hormone. And with that and also measuring thyroid T. Four. And looking at the TSH, wow, that became really cool because I understand before that what we use with measuring basal metabolic rate and peptide binding ideas. Nothing was good. TSS was groundbreaking. So then we can actually essay circulating levels of T. four or indirectly. So you couldn't diagnose again with TSH. But you can certainly get a good idea of how those thyroid levels were managing. But that wasn't enough to push it over. The other thing was and this is key. And colleagues. This is what changed my mind and got me to prescribing synthetic at that point is because we knew that patients need T. Four and T. Three. We know that this combined in its T. three is the metabolically active hormone and desiccated thyroid hormone. It's important you understand This is the combination of T. four t. 3. We found out in the 80s that The majority of T. three comes from T. four. And that changed everything. So then we thought well oh you don't need to give somebody T. Three and T. Four. You can give them T. Four. And a lot of it will be uh in the needs of the body through feedback mechanisms. You're going to have production of T. Four. Now I mentioned that I take time mention that but this was huge. So you have the TSS we became now the gold standard for better or worse for 40 years. And then we looked at you could just use monotherapy. That was the start of it. That's what we thought about. And let let the body's own innate divine design work. Let T. Four predominantly come from T. Three come from T. Four. And then you can activate, inactivate it and do what we can with inactive forms of T. Three. So that's what change it. And finally what got the consumers on board safety, safety, safety. The drug was safely with Iraqi was safe, it was consistent blood levels of T. four hormones. It was long shelf life. That was a problem early on with DTs shelf life. Now that's not the problem anymore. But that was a problem back then. And the big thing was cost boy have things changed then. So cost came down consumers board and that became colleagues. Why we're looking at the age of LT for monotherapy. Now we're finding in the last 10 years people are willing to talk about not all patients are being treated being relieved of symptoms. Yeah, the labs are not is accurate for looking at, we can't see there's no biomarkers petition penetration of T. three. We know that symptoms aren't relieved in everybody. T leave out the rocks in His mono therapy is not the Holy grail for all patients. And remember, we need to treat symptoms and we have to alleviate and minimize comorbidities.