Ask A Pharmacist: Help With Signs And Symptoms of Low Blood Sugar

Hi, I have diabetes, but recently I am not experiencing any symptoms of low blood sugar levels, even though my blood sugar test results suggest that I am. Can you explain what may have caused my lack of symptoms, what are usual signs and symptoms of low blood sugar, what causes low blood sugar, and what is considered a low blood sugar reading?

Background information: Patient is a 38 years old male who has type 2, or non-insulin-dependant, diabetes for the past 5 years. He is on Metformin 500mg three times daily and Glyburide 2.5mg twice daily with meal(s), and according to his doctor, the treatment is currently maintaining his blood sugar levels quite well. He has been just prescribed Propranolol 10mg for stage fright, taken 30 minutes prior to his music recital. He has taken this medication for 3 consecutive nights now.

What may have caused my lack of low blood sugar symptoms?

From the information that you have provided, the main culprit that is masking the symptoms of low blood sugar is propranolol. Propranolol is a beta-blocker that is used to help with stage fright, by reducing symptoms of trembling and fast heart beat. When people have a drop in blood sugar levels, the body compensates by producing more epinephrine and glucagon in order to stimulate the production of blood sugars. It is epinephrine that produces symptoms of sweating, tremors, and racing heart or fast heartbeat, which signals that you are currently experiencing low blood sugar levels. The problem is that when you take propranolol, such signs and symptoms are blocked off or masked. The only symptom that is not masked is sweating. Therefore, if you are to continue with propranolol, and suddenly experience sweating, this may be the only indication that you have low blood sugar levels. You can also use your blood sugar meter to confirm the diagnosis and treat as needed. You should always have a source of sugar on hand at all times, in case you experience low blood sugar levels.

What are usual signs and symptoms of low blood sugar?

Mild signs and symptoms of low blood sugar levels include sweating, trembling, racing heart or fast heartbeat, hunger, sensation of weakness, anxiety and tingling. When your body is severely deprived of sugar, then you may experience confusion, fatigue, disorientation, loss of consciousness and seizures.

Treatment for low blood sugar

The common treatment for low blood sugar is to take 15g of a sugar source (glucose or sucrose), wait for 15 minutes and then retest blood sugar levels. You may need to repeat ingestion of sugar source if still your blood sugar level remains below 70 mg/dL or 4 mmol/L. Some common sugar sources include 3/4 cup of orange or apple juice or non-diet soda, 5-6 pieces of lifesavers, 15 mL of table sugar dissolved in water, 15 mL of honey, or 15g of glucose tablets. For those on Acarbose, you can only use pure glucose sugar source such as 4 Dex4 glucose tablets (each tablet contains 4g of glucose) or 15 mL of honey.
You can buy Dex4 glucose tablets from drugstore.com, Amazon.com or at your local pharmacy.

For those who are unconscious, a treatment of IV glucose or glucagon may be necessary. Treatment of glucagon may not be effective in a malnourished individual.

What causes low blood sugar levels?

(1) Taking too much blood sugar lowering medications such as Insulin, Sulfonylureas (Glyburide and Gliclazide etc) and Meglitnides (such as Repaglinide)
(2) Missing or delaying a meal or snack but having taken blood sugar lowering medications
(3) Alcohol (can lead to low or high blood sugar)
(4) Exercise, more than usual
(5) Antibiotics such as quinolones (ciprofloxacin, norfloxacin, levofloxacin, moxifloxacin etc),
(6) Salicylates (eg: Aspirin) may lower blood sugar especially with Sulfonylurea (Glyburide, Gliclazide etc)
(7) Drug interactions:
Medications that increase levels of Sulfonylureas (gliclazide, glimepiride, glyburide)
Acid Reducer (Cimetidine, Ranitidine, Omeprazole)
Macrolide Antibiotics (clarithromycin, erythromycin)
Antifungal agents (ketoconazole, fluconazole)
MAO inhibitors (phenelzine, tranylcypromine)
Sulfonamides (sulfamethoxazole)
(8) Weight loss may increase insulin sensitivity (body improved response to insulin)

What is considered a low blood sugar level?

In general, low blood sugar is considered below 70 mg/dL or 4 mmol/L (but may varies with individual)

For more information, ask a pharmacist at consultpharmacist.com!

This material is provided as INFORMATIONAL PURPOSES ONLY, and should not be used as a substitute for medical advice, diagnosis or treatment provided by your health care providers such as your physician(s) and/or pharmacist(s).