QUESTION:
I was recently diagnosed with diabetes after glucose was found in my urine and my blood sugar was 310 mg/dL. I have lost about 14 pounds. I was prescribed metformin three times daily and Diabetene each morning, but metformin makes me sick. I now feel spaced out and have a rapid heartbeat despite taking Talliton for blood pressure and heart-rate control. A second doctor reduced metformin to once daily and ordered a fasting test. My morning readings are 135–175 mg/dL, after breakfast 248–284 mg/dL, and at night 94–124 mg/dL. At 94 I feel sick, extremely hungry, and have tingling in my mouth and tongue. Without the medicines I feel better, but my glucose may reach 400. Why do I feel ill at 94, and should I return to the original dose?
Quick Answer
Do not return to the original dose or stop treatment on your own. A new diabetes diagnosis with weight loss, glucose of 310–400 mg/dL, feeling “spaced out,” and rapid heartbeat needs urgent medical reassessment. A reading of 94 mg/dL is not technically low, but symptoms can occur when glucose falls rapidly from chronically high levels. Another diabetes medicine may also be capable of causing true hypoglycemia, so the exact drug must be identified.
Answer by Dr. Albana Greca, MD, MMedSc
Hello Kerry,
Please contact the clinician managing your diabetes today. If you currently feel confused, faint, very weak, short of breath, severely dehydrated, or have persistent palpitations, go to an emergency department.
A glucose of 94 mg/dL is within the usual normal range. Hypoglycemia is generally defined as below 70 mg/dL. However, your body may have adapted to readings in the 200s or higher. A rapid fall toward normal can temporarily cause hunger, tingling, shaking, anxiety or a pounding heartbeat. This is sometimes called relative hypoglycemia.
Do not automatically treat every reading of 94 with large amounts of sugar. Sit down, wash and dry your hands, repeat the test, and follow your clinician’s instructions. If the repeat result is below 70 mg/dL, use the advised low-glucose treatment. Our guide to blood sugar between 45 and 69 mg/dL explains what to do.
Feeling well while off medicine does not make a reading of 400 safe. Severe hyperglycemia can cause dehydration, diabetic ketoacidosis or hyperosmolar hyperglycemic state. Because you are newly diagnosed and have unexplained weight loss, your doctor should also confirm whether you have type 2 diabetes, adult-onset autoimmune diabetes, or another form that may require insulin.
Read our safety guidance for blood sugar over 400 mg/dL. When glucose is 250 mg/dL or higher, especially with illness or new symptoms, ask whether you should test blood or urine ketones. Do not exercise when glucose is very high and ketones are present.
Nausea, diarrhea, stomach discomfort and poor appetite are common when metformin is started, especially if the dose rises quickly. Taking it with food, increasing it gradually, or using an extended-release version may help, but only the prescriber should make these changes.
Metformin alone rarely causes hypoglycemia. However, “Diabetene” cannot be identified reliably from the brand name. Some diabetes tablets stimulate insulin release and can cause true low glucose. Bring the package, strength and instructions to your doctor or pharmacist. Our metformin side-effects guide explains when nausea or diarrhea needs review.
Kidney function must be checked. Persistent vomiting, severe diarrhea or poor fluid intake may cause dehydration and can make continuing metformin unsafe until a clinician assesses you.
Palpitations may result from dehydration, a rapid glucose fall, anxiety, infection, anemia, thyroid disease, electrolyte disturbance, abnormal heart rhythm, uncontrolled blood pressure or medication effects. They should not be blamed on diabetes without examination.
Your clinician should check your pulse, blood pressure, ECG, oxygen level, kidney function and electrolytes. Bring every medicine and supplement. Do not change Talliton or any heart or blood-pressure medicine without medical advice.
Whole-wheat bread still contains carbohydrate. The high result may reflect the bread portion, an elevated fasting level, morning hormones, insufficient medicine effect or reduced insulin production. Vegetables are helpful, but the meal may need protein and a smaller individualized carbohydrate portion.
Record whether you tested one or two hours after the first bite. For many adults, a common target is below 180 mg/dL about one to two hours after starting a meal, although your target may differ. See blood sugar levels after eating.
Go for emergency care now if:
Glucose remains at or above 300 mg/dL with vomiting, abdominal pain, fruity-smelling breath, deep or difficult breathing, chest pain, fainting, confusion, severe weakness, inability to drink, moderate or large ketones, or a persistent rapid or irregular heartbeat.
The safe next step is not choosing between the first and second doses yourself. You need a coordinated plan that lowers glucose without causing intolerable side effects or an unsafe rapid fall.
This educational answer does not replace urgent medical assessment or individualized medication instructions.
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