Drilldown: Medicines
Medicines > fda max 
:
4 g/d or
No fixed maximum; titrated to TSH target or
~200 mg elemental iron/d typical practical limit
:
4 g/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:Beta-lactam_antibiotics|β-lactam antibiotic]] (1) ·
[[:Category:Cephalosporins|Cephalosporin (first-generation)]] (1) ·
[[:Category:Hematinics|Hematinic]] (1) ·
[[:Category:Hormone_replacement|Hormone replacement]] (2) ·
[[:Category:Iron_supplements|Iron supplement]] (1) ·
[[:Category:Lipid-lowering_agents|Lipid-lowering agent]] (2) ·
[[:Category:Omega-3_fatty_acids|Omega-3 fatty acid]] (2) ·
[[: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) ·
'"`UNIQ--vote-0000004E-QINU`"' The EPA+DHA mix is biochemically and clinically distinct from icosapent ethyl'"`UNIQ--ref-0000004F-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-00000050-QINU`"' (1) ·
'"`UNIQ--vote-000004ED-QINU`"', '"`UNIQ--vote-000004EE-QINU`"', '"`UNIQ--vote-000004EF-QINU`"', '"`UNIQ--vote-000004F0-QINU`"', '"`UNIQ--vote-000004F1-QINU`"' (1) ·
'"`UNIQ--vote-0000059A-QINU`"', '"`UNIQ--vote-0000059B-QINU`"' (1) ·
'"`UNIQ--vote-000013CF-QINU`"', '"`UNIQ--vote-000013D0-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) ·
2 g PO BID with meals (4 g/d total) (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) ·
4 g PO daily (as 4 x 1 g capsules once daily, or 2 capsules BID) (1) ·
500 mg PO every 6 hours, or 250 mg every 6 hours for mild infections (1)
preparations:
0.5 g, 1 g capsules (1) ·
1 g soft gelatin capsules containing ~465 mg EPA + ~375 mg DHA as ethyl esters (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) ·
250 mg, 500 mg, 750 mg capsules; 250 mg/5 mL, 125 mg/5 mL suspension; tablets (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)
fda max: (Click arrow to add another value)
onset:
Hours (1) ·
Reticulocyte response at 7-10 days; hemoglobin rise of ~1 g/dL per 3 weeks (1) ·
Triglyceride lowering at 2-4 weeks; max at 8 weeks (1) ·
Triglyceride lowering at 4-8 weeks; CV benefit emerges over months (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) ·
Not well characterized; tissue incorporation over weeks'"`UNIQ--ref-00000051-QINU`"' (1) ·
T4 ~7 days; T3 ~1 day'"`UNIQ--ref-00000036-QINU`"' (1) ·
~1 hour'"`UNIQ--ref-000004F2-QINU`"' (1) ·
~7 days (euthyroid); longer in hypothyroidism (~9-10 days), shorter in hyperthyroidism'"`UNIQ--ref-00000036-QINU`"' (1) ·
~89 hours (EPA, the active metabolite)'"`UNIQ--ref-000013D1-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) ·
90% (oral; food delays but does not reduce absorption)'"`UNIQ--ref-000004F3-QINU`"' (1) ·
Improved with food'"`UNIQ--ref-00000052-QINU`"' (1) ·
Substantially improved with high-fat meal; take with food'"`UNIQ--ref-000013D2-QINU`"' (1) ·
Variable; reduced by food, calcium, iron, PPIs'"`UNIQ--ref-00000037-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; widely used.<sup class="pcp-cn" title="This claim needs a citation.">[[[Pharmacopedia:Citation needed|citation needed]]]</sup> (1) ·
Limited data.<sup class="pcp-cn" title="This claim needs a citation.">[[[Pharmacopedia:Citation needed|citation needed]]]</sup> (1) ·
Limited human data<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 6 results in range #1 to #6.