Thyroid Augmentation

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Chrismander

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Can it be done in someone who is already on synthroid replacement for hypothyroidism? If so would you still use cytomel (monotherapy or added on to synthroid), and how would you even know how to dose it?
 
Any chance you've posted this in the wrong forum?
 
I don't think you'd add cytomel to synthroid.
 
Can it be done in someone who is already on synthroid replacement for hypothyroidism? If so would you still use cytomel (monotherapy or added on to synthroid), and how would you even know how to dose it?
Might actually check t3 and t4 levels first.

it's extremely likely that a pt already on thyroid supplementation from a pcp or endo is already having periodic labs drawn to monitor this. There is a significant chance that any labs we order would be a waste.

Given the above situation(a pt already being given synthroid by a pcp or endo), I would most definitely avoid that line of treatment. It's likely to be duplicative and just create an overall cluster****.
 
T3 added to a patient on T4 already isn't TERRIBLY uncommon and is considered one of the ways to address persistent clinically hypothyroid presentation in the setting of normalized TSH post replacement therapy.

It's pretty safe and not hard at all to monitor. I'd coordinate with the endocrinologist because you usually decrease T4 dose to accommodate.

If you keep up with the hypothyroid literature much, it's evident that anti-TPO antibodies are not uncommon in Hashimoto's, and there's at least some evidence that TPO function can be impaired even in other hypothyroid and even euthyroid patients. If T4 doesn't convert to T3 in the body it's not terribly effective which is probably why so many people have residual symptoms for years after their TSH has normalized.

In some ways T3 augmentation makes even more sense in the hypothyroid depressed population than the euthyroid depressed population since you'd be treating a medical cause of depression (Assuming that some of the depressive symptoms were secondary to an incomplete response to T4 therapy for hypothyroid). I actually lean TOWARD that option for this reason.

Course, I'm a third year resident and the above was directly retrieved rectally so what the hell.
 
T3 added to a patient on T4 already isn't TERRIBLY uncommon and is considered one of the ways to address persistent clinically hypothyroid presentation in the setting of normalized TSH post replacement therapy.

It's pretty safe and not hard at all to monitor. I'd coordinate with the endocrinologist because you usually decrease T4 dose to accommodate.l.

I won't comment on the science behind this either way......but from a logistical and practical standpoint(which trumps everything), this sort of thing is a likely cluster****.......most private practice endos see a ton of patients in an afternoon, and likely aren't interested in 'coordinating' care on a routine hypothyroid patient they don't remember with a psychiatrist who works in another system entirely.....
 
Why would this patient even be seeing an endo for thyroid replacement? Likely a PCP, and plenty of PCPs are interested in collaborating when a psychiatrist reaches out. The problem is more often that we don't try.
 
So to clarify:
Patient 1: Resistant MDD on his third or fourth antidepressant, no hx or sign of hypothyroid, TSH/Free T4 within normal limits. It's kosher to add in a low dose of cytomel for augmentation, as was done in Star*D.

Patient 2: Resistant MDD on his third or fourth antidepressant. Hx Hypothyroid, on a stable dose of synthroid, recent TSH, Free T4 within normal limits. Is it kosher to add cytomel to his existing regimen WITH NO EYE towards fixing "abnormal" thyroid lab studies, but purely as "augmentation" for mood? For instance, someone who's also diabetic and for whom abilify/seroquel wouldn't be so great. Pretend that coordination with PCP/endo is not an issue, I"m talking purely from a feasibility of treatment, and logicalness of a treatment, and side effects/tolerability/safety of treatment.

Thanks!
 
What I wrote was directly talking about Patient 2. Normal free T4 and normal TSH in a hypothyroid patient on T4 replacement can be found without resolution of clinical hypothyroidism. In other words, the lab studies can be completely normal after T4 replacement and they can still be clinically hypothyroid.

T3 is the 'active' form of hypothyroid; While T4 does have some activity it is far less than T3. Most Hashimoto's patients have a high degree of antibodies to Thyroid Peroxidase--the enzyme that converts T4 to T3. Which means even on T4 replacement, normal free T4, and normal TSH, that they aren't converting enough T4 to T3 to have truly normal thyroid function.

Thus, augmenting with T3 makes sense, even if by lab studies alone their hypothyroid appears to be adequately treated. You are not only engaging in an appropriate treatment for depression, but possibly treating a medical cause of depression. You need to coordinate with the prescriber of T4 because generally speaking you need to drop the T4 dose by 25-50mcg when adding T3 on to prevent iatrogenic hyperthyroidism.
 
What I wrote was directly talking about Patient 2. Normal free T4 and normal TSH in a hypothyroid patient on T4 replacement can be found without resolution of clinical hypothyroidism. In other words, the lab studies can be completely normal after T4 replacement and they can still be clinically hypothyroid.

T3 is the 'active' form of hypothyroid; While T4 does have some activity it is far less than T3. Most Hashimoto's patients have a high degree of antibodies to Thyroid Peroxidase--the enzyme that converts T4 to T3. Which means even on T4 replacement, normal free T4, and normal TSH, that they aren't converting enough T4 to T3 to have truly normal thyroid function.

Thus, augmenting with T3 makes sense, even if by lab studies alone their hypothyroid appears to be adequately treated. You are not only engaging in an appropriate treatment for depression, but possibly treating a medical cause of depression. You need to coordinate with the prescriber of T4 because generally speaking you need to drop the T4 dose by 25-50mcg when adding T3 on to prevent iatrogenic hyperthyroidism.

Is this thinking assuming they have a normal T3 value as well? If so I'm not following. If not shouldn't a T3 be drawn first?

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