If a person needs more of a drug to achieve the same effect, this is called what?

If a person needs more of a drug to achieve the same effect, this is called what?

• A. Tolerance
• B. Withdrawal
• C. Dependence
• D. Craving

Answer: (A)

When the body becomes less responsive to a drug after repeated use, requiring a larger amount to achieve the same effect, that is tolerance. The brain and body adapt to continued exposure by changing how they respond to the drug—receptors may become less sensitive or fewer receptors may be available (pharmacodynamic tolerance), and enzymes that break down the drug can increase in activity (pharmacokinetic tolerance). This means you need more of the drug to get the same level of effect. This is different from withdrawal, which are the unpleasant symptoms that appear when the drug is stopped; dependence, which can involve needing the drug to avoid withdrawal and other adaptive changes; and craving, which is a strong desire or urge to use the drug rather than a change in how much drug is needed for effect. For example, someone regularly taking a painkiller may find that over time the same dose relieves less pain, so they take a higher dose to achieve the prior effect.

When the body becomes less responsive to a drug after repeated use, requiring a larger amount to achieve the same effect, that is tolerance. The brain and body adapt to continued exposure by changing how they respond to the drug—receptors may become less sensitive or fewer receptors may be available (pharmacodynamic tolerance), and enzymes that break down the drug can increase in activity (pharmacokinetic tolerance). This means you need more of the drug to get the same level of effect.

This is different from withdrawal, which are the unpleasant symptoms that appear when the drug is stopped; dependence, which can involve needing the drug to avoid withdrawal and other adaptive changes; and craving, which is a strong desire or urge to use the drug rather than a change in how much drug is needed for effect. For example, someone regularly taking a painkiller may find that over time the same dose relieves less pain, so they take a higher dose to achieve the prior effect.