What was the first group of drugs used to decrease tremors before levodopa and dopamine antagonists?

The first group of drugs used to decrease tremors, particularly in conditions such as Parkinson's disease, is anticholinergics. This class of medications works by blocking the action of acetylcholine, a neurotransmitter that can contribute to excessive tremors and muscle rigidity when in imbalance with dopamine levels in the brain.

In Parkinson's disease, the loss of dopaminergic neurons leads to an increase in cholinergic activity. Anticholinergics help to restore this balance, effectively reducing tremor severity and improving mobility in affected individuals. They were widely used before the introduction of levodopa and dopamine agonists, which target the dopaminergic pathways more directly.

While other classes of medications such as beta-blockers might be used to treat tremors, especially in essential tremor, they do not specifically address the underlying neurological mechanisms as effectively as anticholinergics do in the context of Parkinson's disease. Similarly, antidepressants and anticonvulsants do not primarily target the tremor symptoms in the same way that anticholinergics do.