"配药量过多" can be translated into English as "excessive medication dosage" or "over-dispensing of medication".
"Excessive medication dosage" emphasizes that the amount of medication prescribed or administered is more than what is considered appropriate or necessary.
"Over-dispensing of medication" focuses more on the act of dispensing too much medication, which could be due to an error or oversight.
Both expressions are acceptable, and the choice between them may depend on the specific context and the emphasis you wish to place.