Do not change the dose today based on these two readings alone.

If glucose is <70 mg/dL or symptoms occur such as sweating, shaking, severe hunger, palpitations, confusion, or dizziness: take 15 g of fast sugar, for example 3 teaspoons sugar dissolved in water or 3 to 4 glucose tablets, then recheck in 15 minutes. Seek urgent care for confusion, fainting, seizure, or inability to swallow.

A caveat: “Diapride M1” usually contains glimepiride plus metformin, and glimepiride is the medicine here most likely to lower glucose. Sulfonylureas can cause hypoglycemia, especially with missed meals, unusual exercise, alcohol, kidney disease, or in older adults. Linagliptin by itself has low hypoglycemia risk, but the usual adult linagliptin dose is 5 mg once daily; please verify why 2.5 mg nightly was prescribed, since it may be part of a specific combination or individualized regimen. See the official linagliptin label.

For a medication adjustment, contact the prescribing clinician with a 3 to 7 day log: fasting glucose, glucose 2 hours after the start of the main meal, medication timing, meals, and any low-glucose symptoms. A single reading of 90 does not justify reducing or stopping a diabetes medicine without that review.

Tonight: If the patient is feeling well, eating dinner normally, and the prescription is linagliptin 2.5 mg at night, give the usual prescribed 2.5 mg dose. Do not give any extra diabetes medicine. A reading of 90 mg/dL at noon does not require withholding linagliptin.

Tomorrow morning: Do not reduce Diapride M1 on your own after one fasting value of 120 and one post-meal value of 90. Give it with breakfast as prescribed, provided the patient will eat a full breakfast and has not had a true low glucose or symptoms.

Hold the morning Diapride M1 and contact the prescriber urgently before giving it if:

If glucose is <70 mg/dL, treat immediately with 15 g fast-acting carbohydrate, recheck in 15 minutes, and seek emergency help if drowsy, confused, unconscious, having a seizure, or unable to swallow.

The medication most likely to cause a low is the glimepiride component of Diapride M1. It should be taken only with a meal; delayed or skipped meals increase the risk. Do not make a permanent dose change until the prescribing clinician reviews repeated readings, HbA1c, age, kidney function, diet, and any low-sugar episodes.

On the data given, I would not reduce either drug today.

If you are considering de-intensification because there are recurrent documented values <70 mg/dL, symptomatic lows, frailty, reduced intake, CKD, or HbA1c below the individualized target, the agent to reduce is the glimepiride, not linagliptin. Sulfonylureas are the hypoglycemia-producing component, whereas linagliptin has very low intrinsic hypoglycemia risk. The ADA 2026 hypoglycemia guidance supports deintensifying insulin secretagogues when hypoglycemia risk is high.

However, switching Diapride M1 to glimepiride 0.5 mg + metformin 500 mg also cuts metformin, which is not needed for prevention of a sulfonylurea-related low. If clinically indicated, the cleaner approach is:

Also confirm the exact nighttime product. Linagliptin monotherapy is ordinarily 5 mg once daily and does not need renal dose adjustment. A 2.5 mg dose generally makes sense when it is part of a fixed-dose linagliptin-metformin combination dosed twice daily, rather than standalone linagliptin. Linagliptin prescribing information supports 5 mg once daily for the single-ingredient formulation.

My practical choice for this patient tonight/tomorrow, from the values provided: continue both as currently prescribed, obtain fasting and standardized 2-hour post-breakfast/post-dinner values for several days, and review HbA1c, eGFR, meal pattern, age/frailty, and any symptomatic or nocturnal lows. If genuine low readings emerge, reduce the glimepiride exposure first, while preserving metformin rather than empirically reducing linagliptin.