Names and pronunciation
(ti-za′nih-deen) Zanaflex
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Individual generic drug information
Extracted information for tiZANidine only.
(ti-za′nih-deen) Zanaflex
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Func. class.: Skeletal muscle relax- ant, α2-adrenergic agonist
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Chem. class.: Imidazoline
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Do not confuse: tiZANidine/tiaGABine
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ACTION: Increases presynaptic inhibition of motor neurons and reduces spasticity by α2-adrenergic agonism
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USES: Acute/intermittent management of increased muscle tone associated with spasticity, symptoms of MS
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Unlabeled uses: Muscle spasm, MS pain
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Extracted information for tiZANidine only.
CONTRAINDICATIONS: Hyper- sensitivity Precautions: Pregnancy, breastfeeding, children, geriatric patients, hypotension, renal/hepatic disease
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SIDE EFFECTS CNS: Somnolence, dizziness, speech dis- order, dyskinesia, nervousness, halluci- nation, psychosis CV: Hypotension, bradycardia, HF, CAD, MI GI: Dry mouth, vomiting, increased ALT, abnormal LFTs, constipation OTHER: Blurred vision, urinary fre- quency, pharyngitis, rhinitis, tremors, rash, muscle weakness, UTI
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INTERACTIONS Increase: CNS depression—alcohol, other CNS depressants, opioids; do not use together unless absolutely needed Increase: tiZANidine levels—other CYP1A2 inhibitors (acyclovir, amiodarone, famotidine, mexiletine, enoxacin, norflox- acin, propafenone, tacrine, verapamil, zileuton, oral contraceptives, ciprofloxa- cin), fluvoxaMINE; avoid concurrent use Increase: hypotension—ACE inhibitors Increase: effect of rasagiline Increase: rebound hypertension risk—beta-blockers Drug/Herb Increase: CNS depression—kava, St. John’s wort Drug/Lab Test Increase: alk phos, AST, ALT
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Extracted information for tiZANidine only.
DOSAGE AND ROUTES • Adult: PO initial 2mg every 6-8 hours, up to 3 doses in 24 hours; increase by 2-4mg per dose at 1-4 day intervals, max 36mg/day Renal dose • Adult: PO CCr <25 mL/min, start with lower dose
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Available forms: Tabs 2, 4 mg; caps 2, 4, 6 mg Administer • Consistently either with/without food; food may affect absorption • Titrate doses carefully • Avoid use with other CNS depressants • Caps, tabs are equivalent if used on empty stomach
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Extracted information for tiZANidine only.
Assess: • Muscle spasticity at baseline and throughout treatment • Hypotension: gradual dosage in- crease should lessen hypotensive ef- fects; have patient rise slowly from su- pine to upright; watch those patients receiving antihypertensives for in- creased effects • CNS: Increased sedation, dizziness, hallucinations, psychosis; product may need to be discontinued • Vision by ophthalmic exam; corneal opacities may occur • Hepatic studies: baseline, at 1 mo af- ter therapeutic dose is achieved and if clinically indicated during treatment and periodically thereafter • Pregnancy/breastfeeding: use only if benefits outweigh fetal risk; no well- controlled studies; cautious use in breastfeeding, excretion unknown • Beers: avoid in older men; may cause urinary retention
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Evaluate: • Therapeutic response: decreased mus- cle spasticity
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • To rise slowly from lying or sitting to upright position to prevent orthostatic hypotension • To ask for assistance if dizziness, seda- tion occur; to avoid drinking alcohol; to avoid operating machinery, driving until effects known • To discontinue gradually • To avoid hazardous activities until re- action is known • Not to use other products unless ap- proved by prescriber; to avoid use with other CNS depressants, opioids; to get medical assistance if adverse reaction oc- curs • To use gum, lozenges for dry mouth • To report vision changes, hallucina- tions immediately to prescriber • To always take consistently either with food or without food; effects may be al- tered by taking differently
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Extracted information for tiZANidine only.
PHARMACOKINETICS Completely absorbed, widely distrib- uted, peak 1-2 hr, duration 3-6 hr, half-life 2.5 hr, protein binding 30%, metabolized by liver; excreted in urine, feces
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Filter the extracted dose blocks for this individual drug.
• Adult: PO initial 2mg every 6-8 hours, up to 3 doses in 24 hours; increase by 2-4mg per dose at 1-4 day intervals, max 36mg/day Renal dose
Candidate age grouping · source page 1302
• Adult: PO CCr <25 mL/min, start with lower dose
Candidate age grouping · source page 1302