Drilldown: Medicines
Medicines > fda max 
:
5 mg/d or
No fixed maximum; titrated to TSH target or
~200 mg elemental iron/d typical practical limit
:
5 mg/d or
No fixed maximum; titrated to TSH target or
~200 mg elemental iron/d typical practical limit Use the filters below to narrow your results.
generic:
brand:
classes:
[[:Category:5-alpha-reductase_inhibitors|5α-reductase inhibitor]] (1) ·
[[:Category:Androgen_modulators|Androgen modulator]] (1) ·
[[:Category:Antihyperglycemic_agents|Antihyperglycemic agent]] (1) ·
[[:Category:BPH_treatments|Benign prostatic hyperplasia treatment]] (1) ·
[[:Category:DPP-4_inhibitors|DPP-4 inhibitor]] (1) ·
[[:Category:Hematinics|Hematinic]] (1) ·
[[:Category:Hormone_replacement|Hormone replacement]] (2) ·
[[:Category:Incretin_modulators|Incretin pathway modulator]] (1) ·
[[:Category:Iron_supplements|Iron supplement]] (1) ·
[[:Category:Thyroid_hormones|Thyroid hormone]] (2)
mechanism:
None (3) ·
Synthetic T4 (thyroxine); peripherally deiodinated to T3 (triiodothyronine), the active hormone. '"`UNIQ--vote-00000031-QINU`"' Narrow therapeutic index; brand-to-generic switches can shift TSH and require re-titration'"`UNIQ--ref-00000032-QINU`"'. (1) ·
'"`UNIQ--vote-00000032-QINU`"' Brand-to-brand and lot-to-lot variability in T3:T4 ratio is greater than with synthetic levothyroxine, which is why endocrine guidelines prefer the synthetic'"`UNIQ--ref-00000033-QINU`"'. (1)
uses:
'"`UNIQ--vote-00000033-QINU`"', '"`UNIQ--vote-00000034-QINU`"', '"`UNIQ--vote-00000035-QINU`"' (1) ·
'"`UNIQ--vote-00000034-QINU`"', '"`UNIQ--vote-00000035-QINU`"' (1) ·
'"`UNIQ--vote-0000052E-QINU`"', '"`UNIQ--vote-0000052F-QINU`"', '"`UNIQ--vote-00000530-QINU`"' (1) ·
'"`UNIQ--vote-0000059A-QINU`"', '"`UNIQ--vote-0000059B-QINU`"' (1) ·
'"`UNIQ--vote-0000117B-QINU`"' (1)
starting dose:
1.6 mcg/kg/d in young healthy adults; 25-50 mcg/d in elderly or cardiac disease, titrated by TSH at 6-8 weeks (1) ·
30 mg PO daily (1/2 grain); titrate by TSH at 6-8 weeks; 60 mg desiccated thyroid is approximately equivalent to 88-100 mcg levothyroxine (1) ·
325 mg PO daily to TID (=65 mg elemental iron/tablet); alternate-day dosing is now favored by hepcidin physiology for better absorption with less GI burden (1) ·
5 mg PO daily for BPH; 1 mg PO daily for androgenetic alopecia (1) ·
5 mg PO once daily (no renal dose adjustment, unlike sitagliptin) (1)
preparations:
1 mg, 5 mg tablets (1) ·
15, 30, 60, 90, 120, 180, 240, 300 mg tablets (1/4 to 5 grains; 1 grain = 60 mg) (1) ·
25, 50, 75, 88, 100, 112, 125, 137, 150, 175, 200, 300 mcg tablets; oral capsule and IV/IM also available (1) ·
325 mg tablets (65 mg elemental Fe); 220 mg/5 mL liquid (44 mg elemental Fe/5 mL); 142 mg/mL drops; OTC and Rx (1) ·
5 mg tablets; combination with metformin (1)
fda max: (Click arrow to add another value)
onset:
BPH symptom improvement at 3-6 months; prostate volume reduction over 6-12 months; hair regrowth at 6-12 months (1) ·
Postprandial glucose effect within days; HbA1c by 12 weeks (1) ·
Reticulocyte response at 7-10 days; hemoglobin rise of ~1 g/dL per 3 weeks (1) ·
TSH normalization 4-8 weeks (1) ·
TSH normalization 4-8 weeks; symptomatic improvement weeks to months (1)
duration:
halflife:
N/A (incorporated into hemoglobin and tissue stores) (1) ·
T4 ~7 days; T3 ~1 day'"`UNIQ--ref-00000036-QINU`"' (1) ·
~12 hours (effective); terminal much longer'"`UNIQ--ref-0000117C-QINU`"' (1) ·
~5-6 hours in young men, ~8 hours in elderly'"`UNIQ--ref-00000531-QINU`"' (1) ·
~7 days (euthyroid); longer in hypothyroidism (~9-10 days), shorter in hyperthyroidism'"`UNIQ--ref-00000036-QINU`"' (1)
bioavailability:
10-20% (oral; reduced by food, calcium, antacids, PPIs, tea/coffee; enhanced by ascorbate) (1) ·
40-80% (oral); reduced by food, calcium, iron, PPIs, fiber; take fasting with water'"`UNIQ--ref-00000037-QINU`"' (1) ·
Variable; reduced by food, calcium, iron, PPIs'"`UNIQ--ref-00000037-QINU`"' (1) ·
~30% (oral)'"`UNIQ--ref-0000117D-QINU`"' (1) ·
~63% (oral)'"`UNIQ--ref-00000532-QINU`"' (1)
pregnancy:
'''Pregnant individuals should not handle crushed/broken tablets''' (skin absorption risk); can cause hypospadias in male fetus. Not used in pregnancy.<sup class="pcp-cn" title="This claim needs a citation.">[[[Pharmacopedia:Citation needed|citation needed]]]</sup> (1) ·
First-line in pregnancy; dose typically increased 25-30% due to estrogen-driven rise in TBG and fetal demand. Lactation safe at physiologic doses.<sup class="pcp-cn" title="This claim needs a citation.">[[[Pharmacopedia:Citation needed|citation needed]]]</sup> (1) ·
Limited data; switch to insulin where feasible.<sup class="pcp-cn" title="This claim needs a citation.">[[[Pharmacopedia:Citation needed|citation needed]]]</sup> (1) ·
Routinely used; iron requirements rise substantially in pregnancy and lactation.<sup class="pcp-cn" title="This claim needs a citation.">[[[Pharmacopedia:Citation needed|citation needed]]]</sup> (1) ·
Synthetic levothyroxine is the standard-of-care in pregnancy; desiccated thyroid use in pregnancy is not well studied<sup class="pcp-cn" title="This claim needs a citation.">[[[Pharmacopedia:Citation needed|citation needed]]]</sup> (1)
Showing below up to 5 results in range #1 to #5.