Drilldown: Medicines

Flecainide (1) · Guaifenesin (1) · Levothyroxine (1) · Metoprolol (1) · Moxifloxacin (1) · Thyroid (desiccated) (1)

Armour Thyroid, NP Thyroid, Nature-Throid, WP Thyroid (1) · Avelox (oral/IV brand discontinued US); Vigamox, Moxeza (ophthalmic) (1) · Lopressor (tartrate), Toprol XL (succinate) (1) · Mucinex, Robitussin, Tussin (1) · Synthroid, Levoxyl, Tirosint, Unithroid, Euthyrox (1) · Tambocor (US brand discontinued) (1)

Beta Blocker (1) · Cardioselective (β1) (1) · [[:Category:Antiarrhythmics|Antiarrhythmic (Vaughan-Williams class IC)]] (1) · [[:Category:Antibacterials|Antibacterial]] (1) · [[:Category:Expectorants|Expectorant]] (1) · [[:Category:Fluoroquinolones|Fluoroquinolone antibiotic]] (1) · [[:Category:Hormone_replacement|Hormone replacement]] (2) · [[:Category:Mucolytics|Mucolytic]] (1) · [[:Category:Thyroid_hormones|Thyroid hormone]] (2)

Cardioselective β1-adrenergic antagonist. Selectivity is dose-dependent and partially lost at higher doses. (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) · '"`UNIQ--vote-00000D7A-QINU`"' Substantial QT-interval prolongation — the most QT-prolonging fluoroquinolone — limits use in patients on other QT-prolonging agents or with electrolyte abnormalities'"`UNIQ--ref-00000D7B-QINU`"'. (1) · '"`UNIQ--vote-0000104D-QINU`"' Adequate hydration is at least as important as the drug in producing the expectorant effect clinically. Used in combination with dextromethorphan, decongestants, or antihistamines in many proprietary OTC cold preparations. (1) · '"`UNIQ--vote-0000113A-QINU`"' Concomitant β-blocker or CCB is required when used for AF to prevent 1:1 atrial flutter conduction (flecainide can slow atrial rate to a level where AV conduction allows dangerous ventricular rates). CYP2D6 substrate'"`UNIQ--ref-0000113B-QINU`"'. (1)

'"`UNIQ--vote-00000018-QINU`"', '"`UNIQ--vote-00000019-QINU`"' (1) · '"`UNIQ--vote-00000033-QINU`"', '"`UNIQ--vote-00000034-QINU`"', '"`UNIQ--vote-00000035-QINU`"' (1) · '"`UNIQ--vote-000004F5-QINU`"', '"`UNIQ--vote-000004F6-QINU`"', '"`UNIQ--vote-000004F7-QINU`"', '"`UNIQ--vote-000004F8-QINU`"', '"`UNIQ--vote-000004F9-QINU`"' (1) · '"`UNIQ--vote-00000D7C-QINU`"', '"`UNIQ--vote-00000D7D-QINU`"', '"`UNIQ--vote-00000D7E-QINU`"', '"`UNIQ--vote-00000D7F-QINU`"', '"`UNIQ--vote-00000D80-QINU`"', '"`UNIQ--vote-00000D81-QINU`"' (1) · '"`UNIQ--vote-0000104E-QINU`"', '"`UNIQ--vote-0000104F-QINU`"' (1) · '"`UNIQ--vote-0000113C-QINU`"', '"`UNIQ--vote-0000113D-QINU`"', '"`UNIQ--vote-0000113E-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) · 200-400 mg PO q4h (IR); 600-1200 mg PO q12h (Mucinex 12-Hour ER) (1) · 25–50 mg BID (tartrate); 25–100 mg daily (succinate); 12.5 mg daily in HFrEF (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) · 400 mg PO/IV once daily (1) · 50 mg PO BID; titrate to 100-200 mg BID; pill-in-pocket 200-300 mg PO single dose for AF conversion (1)

100, 200, 400 mg IR tablets; 600 mg, 1200 mg Mucinex ER tablets; many liquid formulations and combination products with dextromethorphan, pseudoephedrine, antihistamines (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) · 400 mg tablets; 400 mg/250 mL IV; 0.5% ophthalmic solution (1) · 50, 100, 150 mg tablets (1) · Tartrate: 25, 50, 100 mg tabs; 1 mg/mL IV. Succinate ER: 25, 50, 100, 200 mg. (1)

None · Indication-specific · 40 mg/d · 10 mg/d · 20 mg/d · 80 mg/d · 10 mg/d (adults) · 100 mg/d · 4 g/d · 400 mg/d · 40 mg/d typical; up to 240 mg/d for Zollinger-Ellison · 5 mg/d · 50 mg/d · 600 mg/d · No fixed ceiling; titrate to clinical effect and tolerability with CDC opioid prescribing guidance constraints on morphine-milligram-equivalent (MME) totals · No fixed maximum; titrated to TSH target · TID per eye · Titrated to glucose; no fixed ceiling · Titrated to glucose; no fixed maximum · '''20 mg/day in adults >60 years''' per FDA's 2011-2012 QT-prolongation warning; 40 mg/day in adults ≤60

Other values:

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IV (3) · Oral (6) · topical ophthalmic (1)

1–2 h (PO); immediate (IV) (1) · 30 minutes (1) · AF conversion within hours of single PO dose (1) · Hours (1) · TSH normalization 4-8 weeks (1) · TSH normalization 4-8 weeks; symptomatic improvement weeks to months (1)

12 hours (1) · 24 hours (1) · 4 hours (IR); 12 hours (ER) (1) · 6–12 h (tartrate); 24 h (succinate) (1) · Steady-state at 4-6 weeks (2)

3–7 h (1) · T4 ~7 days; T3 ~1 day'"`UNIQ--ref-0000001A-QINU`"' (1) · ~1 hour'"`UNIQ--ref-00001050-QINU`"' (1) · ~12 hours'"`UNIQ--ref-00000D82-QINU`"' (1) · ~14 hours (adults); longer in elderly and renal impairment'"`UNIQ--ref-0000113F-QINU`"' (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) · High (oral)'"`UNIQ--ref-00001051-QINU`"' (1) · Variable; reduced by food, calcium, iron, PPIs'"`UNIQ--ref-0000001B-QINU`"' (1) · ~50% (1) · ~90% (oral)'"`UNIQ--ref-00001140-QINU`"' (1) · ~90% (oral; not affected by food but reduced by divalent cations)'"`UNIQ--ref-00000D83-QINU`"' (1)

'''Avoid in pregnancy where alternatives exist''' (animal cartilage toxicity).<sup class="pcp-cn" title="This claim needs a citation.">&#91;[[Pharmacopedia:Citation needed|citation&nbsp;needed]]&#93;</sup> (1) · Category C (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 acceptable.<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.'"`UNIQ--ref-0000001C-QINU`"' (1) · Use in fetal SVT (transplacental antiarrhythmic therapy) is established; otherwise weigh against alternatives.<sup class="pcp-cn" title="This claim needs a citation.">&#91;[[Pharmacopedia:Citation needed|citation&nbsp;needed]]&#93;</sup> (1)

OTC in US (1) · Rx-only in US (1) · [[USLegal:Prescription only|Rx-only]] in US (2) · [[USLegal:Prescription only|Rx-only]] in US. '''Contraindicated in structural heart disease''' — CAST trial (1989) showed increased mortality from class IC agents in patients with prior MI; modern use is limited to structurally normal hearts'"`UNIQ--ref-00001141-QINU`"' (1) · [[USLegal:Prescription only|Rx-only]] in US. Carries the same fluoroquinolone-class '''Boxed Warnings''' as ciprofloxacin/levofloxacin'"`UNIQ--ref-00000D84-QINU`"' (1)