Used primarily as a ganglionic blocker to treat severe hypertension when other antihypertensive drugs are ineffective. It works by blocking nicotinic acetylcholine receptors in the autonomic ganglia, reducing sympathetic tone and lowering blood pressure. Due to its significant side effect profile, it is reserved for resistant cases and rarely used as a first-line agent. Has also been investigated in research settings for potential use in substance use disorders, particularly nicotine and stimulant dependence, owing to its action on nicotinic receptors.