Which medications are effective for salivation in ALS?

Excessive salivation (sialorrhea) is caused by a swallowing disorder (dysphagia). In ALS, there is no overproduction of saliva, so the excess saliva in the mouth and throat is caused by the reduced swallowing of saliva (which otherwise occurs unnoticed and continuously). The flow of saliva can be reduced by various medications, which lead to reduced secretion due to their pharmacological effect.

The salivary glands are stimulated by the autonomic nervous system (also known as the “autonomic nervous system”) and the neurotransmitter acetylcholine it contains. Drugs that can inhibit the messenger substance acetylcholine (at the connection between the autonomic nerves and the salivary glands) (“anticholinergic” drugs) can be used to reduce the flow of saliva. Commonly used drugs are amitriptyline, atropine, pirenzepine and ipratropium bromide. These drugs were originally used to treat other illnesses and have the side effect of reducing saliva production. This “side effect” is “exploited” in the treatment of excess salivation. As a result, the former side effect (in other diseases) becomes a main effect in ALS.

A particularly effective medication for reducing salivation is botulinum toxin, which can be injected into the parotid gland (Latin: glandula parotis) or oral salivary gland (Latin: glandula submandibularis) using a fine injection needle under ultrasound guidance. Botulinum toxin is a highly effective preparation for blocking acetylcholine and the saliva formation stimulated by acetylcholine. The effect lasts for two to four months. In most cases, a few days after injection of the medication (and infiltration of the substance into the salivary gland), a significant reduction in saliva formation (and thus excess salivation) can be achieved. The disadvantages are the time-consuming application (injection under ultrasound control, usually by experienced specialists in neurology or ENT medicine) and a diminishing effect, which requires re-injection every two to four months. Due to the disadvantages mentioned, treatment with oral medication is preferable.