Final answer:
Xerostomia is typically a side effect of anticholinergic drugs, which block muscarinic acetylcholine receptors and decrease saliva production.
Step-by-step explanation:
Xerostomia, or dry mouth, is more commonly a side effect of anticholinergic drugs rather than adrenergic drugs. Anticholinergic drugs work by blocking the muscarinic acetylcholine receptors, which can lead to a reduction in saliva production, hence causing xerostomia. On the other hand, drugs affecting the sympathetic system, called sympathomimetic drugs, mimic the actions of adrenergic molecules like norepinephrine and epinephrine but do not typically cause dry mouth as a primary side effect. This leads to a decrease in saliva production and the sensation of dry mouth.