"No medication is specifically designed to treat ET. However, for approximately 60 percent of patients, there are a number of medications that might be of benefit, singularly or in combination, in the treatment of its symptoms."
The following information on medications has been reviewed by Rodger Elble, MD, Southern Illinois University School of Medicine, Springfield, IL, IETF Medical Advisory Board Member
This information is not intended as medical advice.
Please discuss this information with your physician.
The most common medications:
Propranolol (Inderal®) - Propranolol is the only medication approved by the Food and Drug Administration (FDA) for the treatment of limb and head ET, and is available in immediate and long-acting formulations. Propranolol is a beta-blocker, which is a drug used primarily for treating high blood pressure. Side effects of propranolol are usually mild and are more frequent at higher doses. The main side effects are decreased pulse rate and blood pressure. If you have heart failure, diabetes, or asthma, talk with your doctor before taking propranolol. Other beta-blockers such as atenolol, metoprolol, and nadolol can also be beneficial for treating ET.
Primidone (Mysoline®)- Primidone, an anti-seizure medicine, can reduce tremor with a daily dosage. Although it might have initial side effects, such as nausea, poor balance, dizziness, fatigue, drowsiness, and flu-like symptoms, there are few long-term problems. To reduce the possibility of side effects, it is recommended to start with a small dose at bedtime (12.5 mg or one-quarter of one tablet) and gradually increase the dose until tremor is suppressed. Please consult with your physician regarding medication and dosage.
Clonazepam (Klonopin®), diazepam (Valium®), lorazepam (Ativan®), and alprazolam
These anti-anxiety medications may be useful in patients who do not respond to other medications or who have associated anxiety. Side effects include sleepiness, dizziness, depression, fatigue, loss of coordination, memory loss, and confusion. These drugs are usually less effective than propranolol and primidone, and they can be addictive. There is also risk of withdrawal symptoms if the drugs are suddenly stopped.
Gabapentin (Neurontin®) - Gabapentin is a generally well tolerated anticonvulsant that has a modest benefit in ET. It is tried by patients whose tremor is unmanageable by other medications. Side effects include fatigue, slurred speech, drowsiness, impaired balance, and nausea especially when beginning drug therapy. Gabapentin requires multiple doses a day.
Topiramate (Topamax®) - Topiramate is an anticonvulsant that has been shown to be effective in controlling tremor in some patients. Side effects include numbness or tingling, memory loss, and weight loss.
Mirtazapine (Remeron®) - Mirtazapine is an antidepressant. Due to its lack of effectiveness for the majority of patients and its significant side effects, mirtazapine is not recommended for the routine treatment of ET. Adverse effects include confusion, dry mouth, weight gain, frequent urination, balance and gait difficulty, nausea, and blurred vision.
Botulinum Toxin Injections (BOTOX®, Myobloc®) - If medications fail, you may consider therapy that involves injecting botulinum toxin into muscles. Botulinum toxin injections have been useful in the treatment of some patients with head and voice tremor and sometimes hand tremor. The toxin must be placed into target muscles by a trained specialist and repeat injections will be needed approximately every three months. Transient weakness of the injection site is a potential side effect. This treatment can be expensive, so be sure to check with your insurance provider about coverage.
Alcohol- Adults with ET often notice that responsibly drinking alcohol - having one or two drinks before social events for example - reduces tremor for one to two hours. One must consider, though, that a more severe rebound tremor can occur after the effects of alcohol have worn off, especially with excessive alcohol use.
Investigational Medications for ET
Medications currently prescribed for ET provide adequate treatment for only a percentage of people. Several new medications are being tested for effectiveness and safety in the treatment of ET, but information about these drugs is limited. These medications include 1-octanol, sodium oxybate, T2000 and carisbamate.
1-Octanol - Alcohol was found to have a beneficial effect on tremor in a majority of ET patients during the late 1940s. Since then tremor reduction after drinking alcohol often has been used to help confirm a diagnosis of ET, but limitations for its use as an on-going treatment of tremor are apparent.
Reduction of tremor is generally limited to less than one hour after a drink. Consumption of larger amounts of alcohol may eventually be needed to suppress tremor. Ingestion of larger amounts of alcohol may result in a more severe tremor, called rebound tremor, after the effects of the alcohol have passed, and alcoholism may result.
1-Octanol, another type of alcohol, has been shown in research studies to provide tremor reduction while avoiding intoxication. It is currently approved by the United States Food and Drug Administration (FDA) as a food additive and occurs naturally in citrus oils.
In a double-blind, placebo-controlled study of 12 ET patients, the effects of a single dose of 1 mg/kg of 1-octanol caused significant reduction in tremor amplitude compared to placebo for up to 120 minutes, and with no signs of intoxication. The most common side-effect was headache in two 1-octanol subjects, which lasted only a couple of hours.
In a second study, 21 ET patients were given varying single dosages of 1-octanol ranging from 1 mg/kg to 64 mg/kg. Two hours after ingestion, maximum improvement in drawing spirals, handwriting and tremor occurred at all dosage levels, but the higher dosage had a more lasting effect. No outward signs of intoxication were present. Side-effects reported included mild, transient weakness; headache; unpleasant taste; dry mouth; and urinary tract infection. In addition, two of the three subjects in the 64 mg/kg group reported feeling lethargic for several hours. Studies examining multiple daily doses of 1-octanol and different formulations of the drug are currently ongoing at the National Institutes of Health (www.clinicaltrials.gov).
Sodium Oxybate- Sodium oxybate is a central nervous system depressant, and is currently approved by the FDA for excessive daytime sleepiness and cataplexy associated with narcolepsy. Sodium oxybate has a high potential for abuse so in the United States a registry of use monitors the distribution and use of the drug. In other countries it has been used for alcohol withdrawal symptoms and to help maintain abstinence.
Given sodium oxybate’s potential to treat alcohol withdrawal symptoms while discouraging further ingestion, a small pilot study of five patients with various movement disorders was conducted. Two ET patients were included. Sodium oxybate was given twice daily. A tremor reduction of 79% and 48% was observed in the two ET patients while taking 1.5g of sodium oxybate. Mild headache and dizziness were reported by one subject and higher doses led to sedation.
In a study of nine ET patients taking varying dosages, the anti-tremor effects of sodium oxybate were found to be most effective at 1.5g three times a day. An action tremor improvement of 43% and a postural tremor improvement of 54% were reported. The lowest dose maintained for ET subjects was 0.5g three times daily and the highest was 2.5g three times daily.
For most subjects, the effect of the medication was observed 40 to 60 minutes after ingestion and was maintained from four to five hours. Side-effects reported included dizziness, headache, emotionality, nausea, sedation and lack of coordination. Seventy percent of the subjects chose to remain on the medication after the study.
Preliminary findings suggest that sodium oxybate may be an effective treatment for ET. However, further research is necessary. Larger, double-blind, placebo-controlled trials of sodium oxybate are planned to confirm the anti-tremor effect of sodium oxybate. If confirmed, the potential for abuse needs to be addressed.
T2000 (1, 3–dimethoxymethyl-5, 5-diphenyl-barbituric acid) - T2000, a barbiturate, has been investigated as a treatment for ET in two studies. In the first study of 12 ET subjects, T2000 led to a significant reduction in tremor. One subject withdrew because of rash and respiratory infection, but no other side-effects were reported. Similarly in a second study of 22 people, T2000 was found to significantly reduce tremor. However, there was also a significant placebo response. Again, one T2000 subject developed a rash. Preliminary results suggest that there may be some benefit of T2000 for ET. Further research is ongoing (www.clinicaltrials.gov).
Carisbamate - Carisbamate is a new anticonvulsant being investigated as a treatment for ET (www.clinicaltrials.gov). How the drug works is not clear, but results from safety studies in seizure patients have shown that carisbamate is safe and well tolerated. The most common side effects have been dizziness and drowsiness.