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. 2020 Summer;26(3):157–165. doi: 10.46292/sci2603-157

Table 4.

Oral antispasticity medications2426

Medication Dosea Side Effects
Baclofen Initial: 5 mg tid Somnolence, dizziness, asthenia, constipation, nausea, poor muscle tone
GABA-B agonist (Level 1a) 1st line in SCI Max daily dose: 80 mg divided into 3 to 4 doses
Precaution: Dose adjustments in renal disease
Increase: 5 mg/dose every 3 days Avoid abrupt discontinuation
Tizanidineb Alpha-2 adrenergic agonist (Level 1a) Initial dose: 2 mg daily Somnolence, dry mouth, asthenia, dizziness, hypotension
Max daily dose: 36 mg in three divided doses Precaution: Hepatotoxicity; monitor LFTs
Increase: 2–4 mg over 2 to 4 weeks
Discontinuation: decrease dose by 2–4 mg per day
Gabapentin GABA analog (Level 1b) Initial dose: 300 mg tid Dizziness, somnolence, dry mouth, edema, constipation
Max daily dose: 3600 mg in three divided doses Precaution: Dose adjustment in renal impairment
Avoid abrupt discontinuation
Dantroleneb Peripheral calcium inhibitor (Level 1b) 1st line if SCI + cognitive dysfunction, otherwise 2nd line Initial: 25 mg daily × 7 days Muscle weakness (peripheral and respiratory)
Max dose: 100 mg qid Sedation
Increase: 25 mg tid × 7 days Nausea, diarrhea
50 mg tid × 7 days Precaution: Blackbox warning: Hepatotoxicity, symptomatic hepatitis; monitor LFTs
100 mg tid × 7 days
May cause more weakness in patients with marginal strength
Clonidine Alpha-2 adrenergic agonist (Level 1b) Initial: 0.05 mg bid to 0.1 mg bid Orthostasis, bradycardia, dry mouth, constipation, drowsiness
Max daily dose: 0.4 mg in two divided doses Precaution: Abrupt discontinuation may lead to withdrawal symptoms (e.g., rebound hypertension, headache, agitation)
Dose adjustment in renal impairment
Diazepam GABA-A agonist Initial dose: 2 mg tid Drowsiness, impaired memory, decreased attention
Max daily dose: 10 mg qid Precaution: Tolerance, dependency; risk for withdrawal syndrome
Caution in elderly
Avoid in alcohol

Note: bid = twice daily; qid = four times a day; tid = three times a day.

aUpon discontinuation, gradual dose reduction for all medications is recommended. Risk of withdrawal is seen with abrupt discontinuation of baclofen, diazepam, clonidine, and gabapentin. For gabapentin, do gradual dose reduction, discontinuation, or substitution over a minimum of 1 week.

bMonitor liver function tests (LFTs) periodically with dantrolene and tizanidine at baseline, 1 month, 3 months, and 6 months.