D2 receptor occupancy of 85-94% is observed at doses greater than which amount?

D2 receptor occupancy of 85-94% is observed at doses greater than which amount?

• A. 50 mg
• B. 100 mg
• C. 125 mg
• D. 150 mg

Answer: (D)

High D2 receptor occupancy rises with dose, and reaching the 85–94% range requires pushing the dose beyond a certain threshold. In this context, that threshold is about 150 mg, so doses greater than 150 mg tend to produce D2 occupancy in the 85–94% range. This high occupancy helps explain both strong antipsychotic effects at these higher doses and the increased risk of extrapyramidal symptoms. At lower doses, occupancy stays below this high range, offering safer tolerability but often less potent receptor blockade.

High D2 receptor occupancy rises with dose, and reaching the 85–94% range requires pushing the dose beyond a certain threshold. In this context, that threshold is about 150 mg, so doses greater than 150 mg tend to produce D2 occupancy in the 85–94% range. This high occupancy helps explain both strong antipsychotic effects at these higher doses and the increased risk of extrapyramidal symptoms. At lower doses, occupancy stays below this high range, offering safer tolerability but often less potent receptor blockade.