Final answer:
The most appropriate medication intervention would be to adjust the metformin dosage.
Step-by-step explanation:
The most appropriate medication intervention for this patient would be to adjust the metformin dosage. The patient's symptoms of increasing confusion, fever, and memory loss may be indicative of metformin-associated lactic acidosis, a rare but serious side effect of metformin. The dosage of metformin needs to be adjusted or discontinued in such cases.