Tremor is one of the most prevalent and disabling symptoms of MS and is a sign of advanced disease. MS patients also have a variety of speech issues, including those related to voice quality. Some of the speech problems are linked to tremor. Moreover, MS patients have an increased risk of heart disease.
How Inderal works
Propranolol, the active ingredient of Inderal belongs to a class of medications called beta-blockers. It binds to so-called beta-adrenergic receptors and blocks their activity. Adrenaline normally binds to these receptors and increases heart rate and blood pressure, as well as tremors and migraines. So it is thought that by blocking the receptors, Inderal reduces tremors and associated problems in MS patients.
Inderal in clinical trials
Although Inderal has not been tested in clinical trials specifically in patients with MS, its effect on tremors has been tested in other patient groups.
For example, a two-week, double-blind, placebo-controlled study of nine patients with essential or familiar tremor showed that 40-80 mg of Inderal per day reduced tremor severity compared to placebo.
A randomized, double-blind, placebo-controlled crossover study in 14 patients with essential tremor showed that propranolol treatment decreased tremor intensity significantly.
Although propranolol is generally well-tolerated, it should be administered with caution in view of contraindications, which include asthma, congestive heart failure, diabetes mellitus, and atrioventricular block, a type of heart block.
The most common side effects of propranolol are lightheadedness, low blood pressure, fatigue, erectile dysfunction, drowsiness, and headaches.