Drilldown: Medicines

Cetirizine (1) · Levocetirizine (1) · Tizanidine (1)

Xyzal, Xyzal Allergy 24HR (OTC) (1) · Zanaflex (1) · Zyrtec, Zyrtec-D (1)

[[:Category:Alpha-2 adrenergic agonists|Alpha-2 adrenergic agonist]] (1) · [[:Category:Antihistamines|Antihistamine]] (2) · [[:Category:Antispastics|Antispastic]] (1) · [[:Category:H1_receptor_antagonists|Histamine H1 receptor antagonist (second-generation)]] (2) · [[:Category:Skeletal muscle relaxants|Skeletal muscle relaxant (centrally-acting)]] (1)

None (1) · '"`UNIQ--vote-00000391-QINU`"' Minimal CYP metabolism; mostly renally cleared unchanged. Cetirizine is the active racemate; levocetirizine is the active R-enantiomer marketed separately'"`UNIQ--ref-00000392-QINU`"'. (1) · '"`UNIQ--vote-00000950-QINU`"' Mostly renally cleared unchanged; dose-reduce in renal impairment. Like cetirizine, retains slightly more sedation than fexofenadine in some users'"`UNIQ--ref-00000951-QINU`"'. (1)

'"`UNIQ--vote-00000019-QINU`"', '"`UNIQ--vote-0000001A-QINU`"', '"`UNIQ--vote-0000001B-QINU`"', '"`UNIQ--vote-0000001C-QINU`"' (1) · '"`UNIQ--vote-00000393-QINU`"', '"`UNIQ--vote-00000394-QINU`"', '"`UNIQ--vote-00000395-QINU`"' (1) · '"`UNIQ--vote-00000952-QINU`"', '"`UNIQ--vote-00000953-QINU`"' (1)

10 mg PO once daily (5 mg in older adults or if sedation occurs) (1) · 2 mg PO every 6-8 hours; titrate by 2-4 mg per dose every 1-4 days; maximum single dose 16 mg, maximum daily dose 36 mg (1) · 5 mg PO once daily in the evening (1)

5 mg tablets; 2.5 mg/5 mL oral solution; OTC (1) · 5 mg, 10 mg tablets; 5 mg, 10 mg chewables; 1 mg/mL oral syrup; OTC (1) · Tablets 2, 4 mg; capsules 2, 4, 6 mg ('''capsules and tablets are not bioequivalent''': capsules slower with food; tablets faster on empty stomach) (1)

10 mg/d (adults) (1) · 36 mg/day in three divided doses; single dose maximum 16 mg (1) · 5 mg/d (adults) (1)

Oral (3)

None · Hours · 30-60 minutes · 1-2 hours · ~30 min · LDL lowering at 2 weeks, max by 4 weeks · ~1 hour · 15-30 minutes · 15–30 min · 1–2 h · 30–60 min · Antidepressant effect emerges over 1-2 weeks · BP and symptomatic LUTS improvement within 1-2 weeks · BP effect within 1-2 weeks · Clinical improvement within 24-72 hours · Days · Motor improvement over days at therapeutic dose · Over weeks · Postprandial glucose effect within days; HbA1c by 12 weeks · Sleep effect from first dose; antidepressant effect over 1-4 weeks

Other values:

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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 hours (short, requires TID-QID dosing)'"`UNIQ--ref-0000001D-QINU`"' (1) · 8-10 hours (longer in elderly and renal impairment)'"`UNIQ--ref-00000396-QINU`"' (1) · ~8 hours (longer in elderly and renal impairment)'"`UNIQ--ref-00000954-QINU`"' (1)

High (oral); not significantly affected by food'"`UNIQ--ref-00000397-QINU`"' (1) · ~40% (oral); food and formulation substantially alter the absorption profile'"`UNIQ--ref-0000001E-QINU`"' (1) · ~85-90% (oral; not significantly affected by food)'"`UNIQ--ref-00000955-QINU`"' (1)

Generally considered safe; widely used. Cetirizine and loratadine remain the more-studied alternatives.<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. Levocetirizine (the R-enantiomer) is an alternative with similar safety.<sup class="pcp-cn" title="This claim needs a citation.">&#91;[[Pharmacopedia:Citation needed|citation&nbsp;needed]]&#93;</sup> (1) · Limited human data.<sup class="pcp-cn" title="This claim needs a citation.">&#91;[[Pharmacopedia:Citation needed|citation&nbsp;needed]]&#93;</sup> (1)

OTC in US (2) · [[USLegal:Prescription only|Rx-only]] in US. Not a controlled substance, distinguishing it from carisoprodol among muscle-spasm options'"`UNIQ--ref-0000001F-QINU`"' (1)