A patient asks a nurse to explain what drug tolerance means. The nurse responds by telling the patient that when tolerance occurs, it means the patient:

A. An abstinence or withdrawal syndrome occurs with physical dependence, which develops when the body adapts to the presence of a drug and exhibits withdrawal symptoms if the drug is stopped abruptly. Tolerance and dependence are related but separate concepts; tolerance does not automatically imply withdrawal. B. Tolerance involves a decreased response to a drug over time, meaning the patient becomes less sensitive, not more sensitive, to the drug’s effects. Increased sensitivity to side effects is not a feature of tolerance—it may indicate toxicity or other drug interactions instead. C. Psychologic dependence is a behavioral or emotional need to continue taking a drug, often associated with craving, compulsion, or habitual use. Tolerance is a physiologic adaptation in which the body adjusts to the drug, reducing its effectiveness, and does not necessarily involve psychological dependence. D. Tolerance occurs when the patient’s body adapts to repeated drug exposure, resulting in reduced therapeutic effects. To achieve the same clinical benefit, the patient may need higher doses or more frequent administration. This is commonly observed with medications such as opioids, benzodiazepines, certain antihypertensives, and some antiepileptics. Importantly, tolerance can develop to desired effects (like pain relief or sedation) as well as side effects, but it does not inherently indicate addiction or misuse.