Intervention	Level of evidence*	Number of studies	Total number of patients studied	Dosage	Adverse events severity†	Magnitude of effect
Primidone (Mysoline)	A	12	218	Up to 750 mg per day	Mild to moderate (sedation, drowsiness, fatigue, nausea, giddiness, vomiting, ataxia, malaise, dizziness, unsteadiness, confusion, vertigo, acute toxic reaction)	50 percent mean improvement by CRS and accelerometry
Propranolol (Inderal)	A	32	533	60 to 800 mg per day	Mild to moderate (reduced arterial pressure, reduced pulse rate, tachycardia, bradycardia, impotence, drowsiness, exertional dyspnea, confusion, headache, dizziness)	50 percent mean improvement by CRS and accelerometry
Propranolol LA (Inderal LA)	A	2	33	80 to 320 mg per day	Mild (skin eruption, transient dizziness)	30 to 38 percent improvement by accelerometry
Alprazolam (Xanax)	B	2	46	0.125 to 3 mg per day	Mild (fatigue, sedation; potential for abuse)	25 to 34 percent mean improvement in CRS compared with baseline
Atenolol (Tenormin)	B	5	79	50 to 150 mg per day	Mild to moderate (lightheadedness, nausea, cough, dry mouth, sleepiness)	25 percent mean improvement by CRS and 37 percent mean improvement by accelerometry compared with baseline
Gabapentin (Neurontin) monotherapy	B	3	61	1,200 to 1,800 mg per day	Mild (lethargy, fatigue, decreased libido, dizziness, nervousness, shortness of breath)	77 percent improvement by accelerometry and 33 percent improvement by CRS compared with baseline
Sotalol (Betapace)	B	3	50	75 to 200 mg per day	Mild (decreased alertness)	28 percent mean improvement by CRS compared with baseline
Topiramate (Topamax)	B	5	335	Up to 400 mg per day	Mild (appetite suppression, weight loss, paresthesias, anorexia, concentration difficulties)	22 to 37 percent mean improvement in CRS compared with baseline
Clonazepam (Klonopin)	C	3	44	0.5 to 6 mg per day	Mild to moderate (drowsiness)	71 percent mean improvement by accelerometry and 26 to 57 percent improvement in CRS compared with baseline
Clozapine (Clozaril)	C	2	27	6 to 75 mg per day	Mild (sedation); severe (potential agranulocytosis)	45 percent mean improvement by accelerometry
Nadolol (Corgard)	C	1	10	120 to 240 mg per day	None	60 to 70 percent improvement by accelerometry in patients who had previously responded to propranolol
Nimodipine (Nimotop)	C	1	16	120 mg per day	Mild (headache, heartburn)	53 percent improvement by accelerometry and 45 percent improvement in CRS compared with baseline
Botulinum toxin type A (Botox; for hand tremor)	C	6	206	50 to 100 U per arm	Moderate (hand and finger weakness, reduced grip strength, pain at injection site, stiffness, cramping, hematoma, paresthesias)	20 percent improvement in CRS for low- and high-dose botulinum toxin type A for postural tremor at six, 12, and 16 weeks, and 27 percent improvement in kinetic tremor at six weeks (only significant scores listed)
Botulinum toxin type A (for head tremor)	C	3	53	40 to 400 U	Mild to moderate (neck weakness, postinjection pain)	67 percent improvement by accelerometry, moderate to marked improvement by CRS but did not differ from placebo
Botulinum toxin type A (for voice tremor)	C	3	25	0.6 to 15 U	Mild to moderate (breathiness, weak voice, difficulty swallowing)	22 percent improvement with unilateral injection, 30 percent with bilateral injection, 67 percent improvement in self-report