Hypoglycemia, or low blood sugar, occurs when the glucose level in the blood drops below the necessary threshold, typically defined as below 70 milligrams per deciliter (mg/dL). Glucose is the body’s primary source of energy, and its regulation involves a delicate balance between the hormone insulin and the liver’s ability to release stored sugar. Certain medications can disrupt this balance by directly increasing insulin in the bloodstream or by interfering with the body’s natural glucose-regulating mechanisms. Understanding which drugs carry this risk is necessary for anyone managing their health, whether they have diabetes or not.
High-Risk Diabetes Treatments
The highest risk for medication-induced hypoglycemia comes from treatments specifically designed to lower blood sugar in people with diabetes. These medications can cause blood glucose levels to fall too low because their action is often independent of the body’s current glucose needs. Insulin and sulfonylureas are identified as the two classes with the highest standalone risk for causing hypoglycemia.
Insulin therapy involves injecting the hormone directly to help glucose move from the bloodstream into the body’s cells for energy. Hypoglycemia can occur if the dose is too high for the amount of carbohydrate consumed, if a meal is missed, or if there is more physical activity than planned. Errors in matching the dose to food intake and activity levels can quickly lead to low blood sugar.
Sulfonylureas and meglitinides are two classes of oral medications that work by stimulating the pancreas to release more insulin. The danger lies in their mechanism, as they prompt insulin secretion regardless of whether the current blood sugar level warrants it. This forced insulin release can drive blood glucose down, especially if the person delays a meal or exercises more than usual.
Newer Diabetes Medications
This mechanism is distinct from newer diabetes drugs, such as SGLT2 inhibitors or GLP-1 agonists, which generally have a much lower risk of causing hypoglycemia when used alone. The potent and constant insulin-releasing effect of sulfonylureas and meglitinides carries a persistent risk of low glucose episodes.
Medications Prescribed for Other Conditions
Hypoglycemia can also occur as an unintended side effect of drugs prescribed for conditions other than diabetes, or through drug-drug interactions. These instances are often less frequent than those caused by primary diabetes treatments, but they pose a risk to the general public. The risk is particularly elevated for individuals with underlying health issues or who are taking multiple medications.
Certain antibiotics, notably fluoroquinolones (like ciprofloxacin or levofloxacin) and sulfonamides, have been associated with unexpected drops in blood sugar. Fluoroquinolones are thought to induce hypoglycemia by enhancing insulin secretion from the pancreatic beta cells, similar to sulfonylureas. This can occur even in people who are not taking diabetes medication, but the risk is compounded when taken with insulin secretagogues.
Cardiovascular medications, particularly beta-blockers, present a dual concern regarding glucose regulation. Beta-blockers can sometimes lead to lower blood sugar, potentially by interfering with glucose metabolism. A more serious concern is their ability to mask the common warning signs of hypoglycemia, such as a rapid heart rate and tremors.
Beta-blockers achieve this masking effect by blocking the action of adrenaline, which is normally released during a low blood sugar event to trigger these symptoms. As a result, a person may not recognize they are becoming hypoglycemic until the episode is severe, leaving only signs like sweating unmasked. Alcohol consumption is another factor that interferes with glucose regulation, as it impairs the liver’s ability to release stored glucose into the bloodstream, increasing the risk of low blood sugar, especially when drinking without eating.
Recognizing and Responding to Low Blood Sugar
Recognizing the symptoms of hypoglycemia is the first step in effective management. Mild-to-moderate low blood sugar can present with a variety of physical and mental changes. Common early signs include shaking, sweating, nervousness, hunger, and a rapid heart rate. As the condition worsens, symptoms can progress to confusion, difficulty concentrating, slurred speech, or even loss of consciousness.
If symptoms are present and blood sugar is confirmed to be below 70 mg/dL, the standard immediate treatment is the “15-15 Rule”. This involves consuming 15 grams of fast-acting carbohydrate, such as four ounces of fruit juice, regular soda, or three to four glucose tablets. Fast-acting carbohydrates are preferred because they are quickly absorbed into the bloodstream to raise the glucose level.
After consuming the carbohydrate, the person should wait 15 minutes and then recheck their blood sugar. If the level remains below 70 mg/dL, the 15-gram carbohydrate dose should be repeated until the glucose level is back in the target range. To minimize the risk of a low blood sugar episode, individuals on high-risk medications should avoid skipping meals and coordinate their medication timing with their food intake. Wearing medical identification can also be a helpful precaution in case a severe hypoglycemic event occurs.