True or false: The lower the selectivity of a drug, the more likely it is to cause side effects.

The statement is true because a drug's selectivity relates to how specifically it binds to its target receptors compared to others in the body. When a drug has lower selectivity, it means it interacts with multiple receptor types rather than a specific one. This broader interaction can lead to a greater likelihood of side effects, as the drug can inadvertently affect various physiological systems and processes.

For example, an anticholinergic medication that does not selectively block only the target muscarinic receptors may also interact with nicotinic receptors or other pathways, resulting in unwanted effects like dry mouth, blurred vision, or urinary retention. Thus, a drug's lack of selectivity significantly increases the potential for adverse effects, making the statement accurate.