Drilldown: Medicines

Famotidine (1) · Hydrochlorothiazide (1) · Levothyroxine (1) · Thyroid (desiccated) (1)

Armour Thyroid, NP Thyroid, Nature-Throid, WP Thyroid (1) · Microzide; mostly prescribed generically (1) · Pepcid, Pepcid AC, Pepcid Complete (1) · Synthroid, Levoxyl, Tirosint, Unithroid, Euthyrox (1)

[[:Category:Antihypertensives|Antihypertensive]] (1) · [[:Category:Antisecretory_agents|Gastric acid suppressant]] (1) · [[:Category:H2_receptor_antagonists|Histamine H2 receptor antagonist]] (1) · [[:Category:Hormone_replacement|Hormone replacement]] (2) · [[:Category:Thiazide_diuretics|Thiazide diuretic]] (1) · [[:Category:Thyroid_hormones|Thyroid hormone]] (2)

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-00000138-QINU`"' Decreases urinary calcium (used in stone prevention); raises serum uric acid, glucose, and lipids modestly; non-anion-gap hypokalemic metabolic alkalosis is the characteristic electrolyte pattern'"`UNIQ--ref-00000139-QINU`"'. (1) · '"`UNIQ--vote-00000255-QINU`"' Less potent and shorter-acting than PPIs but with faster on-effect; suitable for on-demand acid suppression. Largely renally cleared; dose-adjust in renal impairment to avoid CNS effects (confusion in elderly)'"`UNIQ--ref-00000256-QINU`"'. (1)

'"`UNIQ--vote-00000033-QINU`"', '"`UNIQ--vote-00000034-QINU`"', '"`UNIQ--vote-00000035-QINU`"' (1) · '"`UNIQ--vote-00000034-QINU`"', '"`UNIQ--vote-00000035-QINU`"' (1) · '"`UNIQ--vote-0000013A-QINU`"', '"`UNIQ--vote-0000013B-QINU`"', '"`UNIQ--vote-0000013C-QINU`"', '"`UNIQ--vote-0000013D-QINU`"' (1) · '"`UNIQ--vote-00000257-QINU`"', '"`UNIQ--vote-00000258-QINU`"', '"`UNIQ--vote-00000259-QINU`"', '"`UNIQ--vote-0000025A-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) · 12.5-25 mg PO once daily (1) · 20 mg PO twice daily, or 40 mg at bedtime (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)

10 mg, 20 mg, 40 mg tablets; chewables; 40 mg/5 mL oral suspension; 10 mg/mL IV (1) · 12.5 mg capsules; 12.5, 25, 50 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)

160 mg/d (Zollinger-Ellison); 80 mg/d for routine indications (1) · 50 mg/d (hypertension); up to 200 mg/d (edema) (1) · No fixed maximum; titrated to TSH target (2)

IV (2) · Oral (4)

1 hour PO; minutes IV (1) · Diuresis at 2 hours; antihypertensive effect within days, max at 3-4 weeks (1) · TSH normalization 4-8 weeks (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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2.5-3.5 hours; longer in renal impairment'"`UNIQ--ref-0000025B-QINU`"' (1) · 6-15 hours'"`UNIQ--ref-0000013E-QINU`"' (1) · T4 ~7 days; T3 ~1 day'"`UNIQ--ref-00000036-QINU`"' (1) · ~7 days (euthyroid); longer in hypothyroidism (~9-10 days), shorter in hyperthyroidism'"`UNIQ--ref-00000036-QINU`"' (1)

40-45% (oral; not significantly affected by food)'"`UNIQ--ref-0000025C-QINU`"' (1) · 40-80% (oral); reduced by food, calcium, iron, PPIs, fiber; take fasting with water'"`UNIQ--ref-00000037-QINU`"' (1) · 65-75% (oral)'"`UNIQ--ref-0000013F-QINU`"' (1) · Variable; reduced by food, calcium, iron, PPIs'"`UNIQ--ref-00000037-QINU`"' (1)

None (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) · Generally considered safe; widely used. Cleared in lactation at low levels.<sup class="pcp-cn" title="This claim needs a citation.">&#91;[[Pharmacopedia:Citation needed|citation&nbsp;needed]]&#93;</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.">&#91;[[Pharmacopedia:Citation needed|citation&nbsp;needed]]&#93;</sup> (1)

OTC (10-20 mg) and [[USLegal:Prescription only|Rx-only]] (higher doses) in US (1) · [[USLegal:Prescription only|Rx-only]] in US (3)