PeskyPeater
Member
@haidut Requesting an increase of t4 in the formula (T4/T3) to 3:1 or at least 2.3:1 please, so it is more brain favorable and also to compensate for coffee use and calcium supplements.
Also I don't understand the origin of practice used for the logic of 3:1 ratio. Is this based on taking say cynoplus in a fasted state or with food? It seems tablets with t4 in them have a lowered absorption rate that results in an effective ratio of 2:1. Unless it is taken in a fasted state, then 3:1 would also be favorable in this liquid form at least to compensate for some losses that i'm describing below..
Looking at the bio-availability of T3 from tablets 95% is absorbed when taken with food, no problemo. And thyroid in liquid form is better absorbed than in tablet form:
But it seems T4 has a somewhat lesser bio-availability when taken with calcium carbonate, 25.8% less [10], study referenced in Absorption of Levothyroxine When Coadministered with Various Calcium Formulations
And it seems liquid T4 has lesser bio-availability when taken with coffee, average of 32.5% less. See attached study below.
Taken with a meal with coffee or in fasted state the absorption of liquid T4 is similar:
But taken with coffee, less is absorbed:
Also I don't understand the origin of practice used for the logic of 3:1 ratio. Is this based on taking say cynoplus in a fasted state or with food? It seems tablets with t4 in them have a lowered absorption rate that results in an effective ratio of 2:1. Unless it is taken in a fasted state, then 3:1 would also be favorable in this liquid form at least to compensate for some losses that i'm describing below..
Looking at the bio-availability of T3 from tablets 95% is absorbed when taken with food, no problemo. And thyroid in liquid form is better absorbed than in tablet form:
*... Among 102 patients, dissatisfied with their therapy with L-T4 tablets (in a mean dose of 88 ± 34.7 µg), taken before the meal, 66.6% reported improvement in the quality of life and better adherence after switching to liquid L-T4 ingested with breakfast [45]. Treatment with liquid l L-T4 formulation can be considered also in patients who are willing to keep their daily habits [46].
But it seems T4 has a somewhat lesser bio-availability when taken with calcium carbonate, 25.8% less [10], study referenced in Absorption of Levothyroxine When Coadministered with Various Calcium Formulations
In a previous cohort study performed by Singh et al. (8), subjects received 1200 mg of elemental calcium as calcium carbonate taken as a single 3000 mg daily dose with their levothyroxine for a period of 3 months. This resulted in a modest but significant decrease in mean serum free T4 and total T4 levels as well as an increase in serum TSH (the mean serum TSH increased from 1.6 to 2.7 mIU/L). A follow-up single-dose pharmacokinetic study was performed with 2000 mg of elemental calcium (5000 mg of calcium carbonate) given simultaneously with 1 mg of levothyroxine and similarly showed a reduction in the expected rise of serum total T4, free T4, and total triiodothyronine levels (10).
And it seems liquid T4 has lesser bio-availability when taken with coffee, average of 32.5% less. See attached study below.
2.4. Impact of Food
Intake on Pharmacokinetics and Pharmacodynamics of Levothyroxine L-T4 absorption and bioavailability, with regard to the food, depend on the drug formulation (tablets, an oral liquid form, or soft gel capsules). In some countries tablets are the only available L-T4 formulation
Taken with a meal with coffee or in fasted state the absorption of liquid T4 is similar:
2.4.2. Liquid Form
In vitro studies proved the stability of liquid L-T4 formulation in beverages such as milk, tea, coffee, coffee with milk, and orange juice [39]. The liquid form has also a faster onset of absorption, compared to tablets (AUC0-2h (ng*h/mL): 99.1 ± 22.7 vs. 68.4 ± 32.8; tmax (h): 1.96 ± 1.07 vs. 2.25 ± 0.99). Greater early exposure and faster time to maximal concentration can minimize the risk of drug-food interactions [15].
Marina et al. [40] examined fT4 levels in 14 patients taking 200 µg of oral liquid L-T4; seven of them administered L-T4 while fasting, and seven with breakfast consisting of six cookies (132 kcal, 9.1% fat, 76.9% carbohydrate, 7.7% protein, 3.8% fiber) and one cup of espresso or cappuccino, both with 5 g of sucrose. The results were comparable in both groups.
In another study on 59 hypothyroid patients, Morelli et al. [41] found no significant differences in the TSH level when administering liquid L-T4 with breakfast, or 10 and 30 min before (1.52 ± 0.73 mU/L, 1.46 ± 0.81 mU/L, and 1.25 ± 0.7 mU/L respectively).
Cappelli et al. [42] conducted a randomized, double-blind, placebo-controlled trial on 77 hypothyroid patients. They assessed whether the patient’s usual breakfast (mixed with tea, coffee, milk, cappuccino, orange juice, etc.) may influence liquid L-T4 absorption. Pharmaceuticals 2021, 14, 206 5 of 20 Serum TSH, fT4, and fT3 levels were comparable in patients administering liquid L-T4 formulation (in a median dose of 75 µg) with breakfast, and 30 min before. The authors concluded that liquid L-T4 can be ingested directly with the meal.
Pirola et al. [43] got similar results for the same median dose of L-T4 (75 µg), on an extensive set of 761 patients. A possibility to administer liquid L-T4 with food may have a positive influence on patient compliance and well-being [44].
...*
But taken with coffee, less is absorbed:
2.8. Levothyroxine–Coffee Interaction
Several studies on patients with hypothyroidism revealed that coffee could decrease the efficacy and safety of L-T4 treatment. The proposed mechanism for this interaction was the sequestration of L-T4 by coffee and in consequence, altered intestinal absorption of the drug [60]. Benvenga et al. [61] investigated the influence of espresso (without milk or sugar) when co-administered with L-T4. Six hypothyroid and nine healthy women were administered two 100 µg L-T4 tablets swallowed with (1) coffee, (2) water, or (3) water followed by coffee 60 min later. Th authors measured average and peak incremental rise of serum T4 concentrations and time to reach maximal serum level. Compared to water, coffee significantly lowered the incremental rise of serum T4 level, both average (by 36% in thyroid patients and 29% in volunteers) and peak (by 30% and 19%, respectively). It also significantly delayed time to reach maximal serum level (by 38 and 43 min). As no significant difference was found between groups (2) and (3), it was suggested that 1h break between coffee and L-T4 is enough to prevent the interaction.
Attachments
Last edited: