Nicotine's effect on alprazolam can lead to reduced efficacy because it increases metabolism.

• A. Nicotine decreases benzodiazepine metabolism, increasing effectiveness.
• B. Nicotine has no effect on metabolism.
• C. Nicotine increases benzodiazepine metabolism, which makes alprazolam less effective.
• D. Nicotine increases benzodiazepine potency.

Answer: (C)

Nicotine can induce hepatic enzymes, which speeds up the metabolism of drugs processed by those enzymes. When a benzodiazepine like alprazolam is metabolized more quickly, its levels in the blood drop and the duration of its effect shortens. That means the same dose may produce a weaker anxiolytic and sedative effect, so the overall efficacy appears reduced. The idea being tested is that nicotine increases benzodiazepine metabolism, leading to lower alprazolam exposure and diminished effectiveness. The other options describe scenarios that would either increase the drug’s effect, show no change, or increase potency, none of which explain a decrease in efficacy. In clinical terms, patients who smoke and take alprazolam might need dose adjustments under supervision to maintain the desired effect.