Drilldown: Medicines
Medicines > fda max 
:
4 g/d (rarely tolerated due to GI effects) or
No fixed maximum; titrated to TSH target
& routes:
oral
:
4 g/d (rarely tolerated due to GI effects) or
No fixed maximum; titrated to TSH target
& routes:
oral Use the filters below to narrow your results.
generic:
brand:
classes:
mechanism:
None (1) ·
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-00000016-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-00000017-QINU`"'. (1)
uses:
'"`UNIQ--vote-00000018-QINU`"', '"`UNIQ--vote-00000019-QINU`"' (1) ·
'"`UNIQ--vote-00000033-QINU`"', '"`UNIQ--vote-00000034-QINU`"', '"`UNIQ--vote-00000035-QINU`"' (1) ·
'"`UNIQ--vote-00000D38-QINU`"', '"`UNIQ--vote-00000D39-QINU`"', '"`UNIQ--vote-00000D3A-QINU`"', '"`UNIQ--vote-00000D3B-QINU`"', '"`UNIQ--vote-00000D3C-QINU`"', '"`UNIQ--vote-00000D3D-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) ·
250-500 mg PO QID; 7.5-12.5 mg/kg IV q6h; topical and ophthalmic per formulation (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)
preparations:
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) ·
250, 500 mg base or stearate tablets; ER tablets; ethyl succinate 200 mg/5 mL suspension; 500 mg, 1 g IV (lactobionate); 2% topical solution/gel; 0.5% ophthalmic ointment (1)
fda max: (Click arrow to add another value)
routes: (Click arrow to add another value)
onset:
duration:
halflife:
bioavailability:
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-0000001B-QINU`"' (1) ·
~30-65% (oral; acid-labile, hence enteric-coated formulations; food affects absorption variably)'"`UNIQ--ref-00000D3F-QINU`"' (1)
pregnancy:
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) ·
Generally considered safe; commonly used in pregnancy.<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.'"`UNIQ--ref-0000001C-QINU`"' (1)
Showing below up to 3 results in range #1 to #3.