Drilldown: Medicines

Levothyroxine (1) · Magnesium (oxide, citrate, sulfate, hydroxide, gluconate, chloride salts) (1)

Mag-Ox, Slow-Mag, MagCitrate, Milk of Magnesia (hydroxide); IV sulfate generic (1) · Synthroid, Levoxyl, Tirosint, Unithroid, Euthyrox (1)

hydroxide)]] (1) · torsades)]] (1) · [[:Category:Antacids|Antacid (hydroxide)]] (1) · [[:Category:Antiarrhythmics|Antiarrhythmic (IV sulfate (1) · [[:Category:Electrolyte_replacements|Electrolyte replacement]] (1) · [[:Category:Hormone_replacement|Hormone replacement]] (1) · [[:Category:Osmotic_laxatives|Osmotic laxative (citrate (1) · [[:Category:Thyroid_hormones|Thyroid hormone]] (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-00001302-QINU`"' Renally cleared; accumulation in advanced CKD can produce neuromuscular and cardiac depression. Hypomagnesemia frequently co-exists with hypokalemia and is often the reason refractory potassium loss does not correct until magnesium is repleted. (1)

'"`UNIQ--vote-00000033-QINU`"', '"`UNIQ--vote-00000034-QINU`"', '"`UNIQ--vote-00000035-QINU`"' (1) · '"`UNIQ--vote-00001303-QINU`"', '"`UNIQ--vote-00001304-QINU`"', '"`UNIQ--vote-00001305-QINU`"', '"`UNIQ--vote-00001306-QINU`"', '"`UNIQ--vote-00001307-QINU`"', '"`UNIQ--vote-00001308-QINU`"', '"`UNIQ--vote-00001309-QINU`"' (1)

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) · Replacement oxide 400-800 mg/d in divided doses (high diarrhea rate); citrate 200-400 mg/d (better tolerated, better absorbed); IV sulfate 1-2 g over 5-60 minutes for hypomagnesemia or torsades; eclampsia 4-6 g IV loading then 1-2 g/h (1)

25, 50, 75, 88, 100, 112, 125, 137, 150, 175, 200, 300 mcg tablets; oral capsule and IV/IM also available (1) · Oxide 400, 500 mg tablets (240, 300 mg elemental); citrate 100, 150, 200 mg tablets; hydroxide oral suspension 400 mg/5 mL; sulfate IV 500 mg/mL ampules (1)

Indication-specific; renal clearance limits tolerable cumulative dosing (1) · No fixed maximum; titrated to TSH target (1)

None · Oral · IV · topical · IM · intranasal · rectal · Subcutaneous · Topical ophthalmic · ophthalmic · intramuscular · intravenous · transdermal · vaginal · Subcutaneous (abdomen · sublingual · thigh · Inhaled · SC · intra-articular

Other values:

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Oral: hours; IV: minutes (1) · TSH normalization 4-8 weeks; symptomatic improvement weeks to months (1)

None · 24 hours · 4-6 hours · 12 hours · 6-8 hours · Daily dosing · 8-12 hours · 12-24 hours · Hours · Hours per application · 24 hours (HS dosing) · 24 hours (once-daily dosing) · 24 h · N/A · N/A (replacement) · Variable · ~7-8 hours · 3-5 hours · 4-6 hours (IR); 24 hours (ER) · 6-12 hours

Other values:

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Not meaningfully described (electrolyte; renally cleared) (1) · ~7 days (euthyroid); longer in hypothyroidism (~9-10 days), shorter in hyperthyroidism'"`UNIQ--ref-00000036-QINU`"' (1)

40-80% (oral); reduced by food, calcium, iron, PPIs, fiber; take fasting with water'"`UNIQ--ref-00000037-QINU`"' (1) · Highly salt-dependent: citrate ~25-30%; oxide ~4% (limited and causes osmotic diarrhea); chloride ~12% (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.">&#91;[[Pharmacopedia:Citation needed|citation&nbsp;needed]]&#93;</sup> (1) · IV sulfate is the cornerstone of eclampsia/preeclampsia management; oral replacement also safe.<sup class="pcp-cn" title="This claim needs a citation.">&#91;[[Pharmacopedia:Citation needed|citation&nbsp;needed]]&#93;</sup> (1)

OTC (oral salts) and [[USLegal:Prescription only|Rx-only]] (IV) in US (1) · [[USLegal:Prescription only|Rx-only]] in US (1)