Dr Alan McDaniel “hit a home run” with this excellent review of thyroid hormone physiology, diagnosis and treatment. After more than 20 years of specializing in thyroid treatment, having read dozens of books on thyroid and attended numerous lectures on thyroid, I still enjoy learning new “pearls” and this article best matches my approach to managing thyroid disorders. Dr Rollins.
Diagnose and Treat Hypothyroidism in 2021: New Endocrinology
by Alan McDaniel, MD. Originally printed in the Townsend Letter.
Pearls
– total T3 / rT3 ratio is arguably the best lab test to know thyroid status – at least initially we should always check these – ideal is 10-14, low is <8 – if low it typically means we need to lower T4 and/or add T3
– the “right” ratio of Rx T4 to T3 is somewhere between 70/30% and 100/0% – recall desiccated thyroid is 80/20% so will work for many folks – e.g. T4 75mcg with T3 25mcg would be 75/25% ratio
– we should dose all thyroid q12 hours with evening dose >4 hours before bedtime – e.g. 6am and 6pm
– he recommends labs mid-doses, at 6 hours – getting labs at 4 hours is ok, I might try 6 hours after am dose to get the “midrange” – probably 4-6 hours is still ok as we’re used to 4 hours
– we should always titrate up the dosage – with T4 by 25mcg, T3 by 5mcg, dessicated by 15mg – and increase weekly to just below target dose
– target dose is about 0.75mcg/lb for T4 and 1mg/lb for dessicated (this is lean body mass so take into account if the patient is overweight!)
– stop using methocel – i quit using quite a while ago due to variable absorption – i was pleased to see he agrees
– when low on thyroid, thyroid receptors upregulate so they are primed for thyroid – this is why we should titrate up the dosage
– also, some things can appear as too much thyroid when starting thyroid rx – e.g. caffeine, low E, low BG, low adrenals – when starting thyroid consider having patient wean off caffeine, and look for the other conditions
– we should always keep free T4 in the low normal range, actually down to about 0.8 is ok
