How is an intention tremor treated?

Nothing or meds: If it's thought to be due to parkinson's or something similar medications such as sinemet (carbidopa and levodopa) are trialed. There are a few different causes of tremor and not all are responsive to medications.

ET medications: Intention tremor is usually associated with essential tremor. There are a few medicines that can help with this. The most potent are probably primidone, Propranolol (and other beta blockers), and topiramate. You can also try non-medicinal techniques such as using heavier objects (i.e. Bigger pen when writing), and bracing your elbow. See a movement disorders neurologist.