When essential tremor (ET) is early and mild, symptoms generally don’t interfere with daily tasks. If symptoms worsen, medication may be prescribed to reduce the speed (frequency) and amplitude (size) of motion. One type of drug used to control ET is called a beta blocker.
As the name suggests, the action of the drug blocks the effect of adrenaline on specific receptors. There are different types of beta blockers. One type is used after a heart attack to reduce risk of another attack. Others are used to regulate abnormal heart rhythm (arrhythmia) or lower blood pressure. A type that opens up blood vessels may help lessen migraine headaches.
One particular beta blocker, propranolol, is used to control ET and is usually the first choice for younger patients. It is thought that propranolol blocks tiny sense organs called spindles, which sense the stretch of a muscle as well as its speed, but the exact mechanism is unknown. It appears to be most effective with tremor of the hands and arms, less so with head tremors.
Propranolol side effects
Propranolol has five commonly reported side effects:
- A slower heart rate –People who exercise vigorously may not be able to achieve their target heart rate. While they still get cardiovascular benefits from exercise, they should talk to their doctors to adjust their target heart rate so they don’t push themselves to the point of fatigue. Certain conditions such as unstable congestive heart failure, asthma or some types of blockage in the heart should not take propranolol due to this effect.
- Fatigue – This is a result of a lower heart rate, and can create a sensation of apathy (lack of interest) regarding normal daily activities.
- Depression – A sense of depression may occur both due to lower blood pressure and fatigue.
- Dizziness, lightheadedness, fainting spells – With a slower heart rate and lower blood pressure, the brain may get less oxygen, leading to a dizziness or feeling lightheaded. Fainting is nature’s way of making a person suddenly lie down. Getting the head on the same horizontal level as the body means that the pumping heart does not have to compete with gravity, so blood flow suddenly increases to the brain and the person quickly regains consciousness.
- Erectile dysfunction – For male ET patients, lower blood pressure plus slowed heartbeats means that not enough blood is available during sexual arousal to achieve and maintain a full erection.
Patients become discouraged
For roughly half of ET patients, propranolol and other medications simply don’t work. For the other half who do experience a reduction in tremors, side effects may increase as the dosage is upped in response to tremor progression. According to Associate Professor of Neurology Peter Hedera, MD (Vanderbilt University), “Many patients prefer subtherapeutic levels of their drug because its side effects are so troublesome. Overall, the data for medications used to treat essential tremor are ‘humbling’ because they show that neurologists are unable to serve about half of patients effectively ‘without sometimes making treatment worse than the disease.’”i
Drug-free ET treatment alternative
When ET reaches a stage in which it no longer responds to medication and is creating impaired function, the Sperling Medical Group offers a drug-free alternative to surgical interventions such as Deep Brain Stimulation (DBS) or radiofrequency thalamotomy. Our noninvasive procedure called MRI-guided Focused Ultrasound (MRgFUS) can deaden the very tiny area in the brain that is not functioning properly. This outpatient procedure is immediately effective in greatly reducing hand tremor in the dominant hand. Although it is not guaranteed effective for all patients, the majority experience durable relief and enhanced quality of life. For more information, contact the Sperling Medical Group.
iVanderbilt University School of Medicine’s 38th Annual Contemporary Clinical Neurology Symposium. What Is the Best Treatment for Essential Tremor? Reported in Neurology Reviews. 2015 November;23(11):12-15.