Dozens of medications can cause hypoglycemia, and they fall into two broad categories: diabetes drugs designed to lower blood sugar, and non-diabetes drugs that do so as an unintended side effect. Blood sugar below 70 mg/dL is generally considered low, though symptoms like shakiness, sweating, and confusion typically don’t appear until levels drop below 55 mg/dL.
Diabetes Medications With the Highest Risk
Not all diabetes drugs carry equal hypoglycemia risk. The two classes most likely to cause dangerously low blood sugar are insulin and sulfonylureas, because both raise insulin levels regardless of how much glucose is in your blood at the time.
Insulin, whether injected or delivered by a pump, is the most common culprit. Eating less than expected, exercising more, or mistiming a dose can all tip the balance. Sulfonylureas (glimepiride, gliclazide, glipizide, glyburide) work by stimulating the pancreas to release more insulin, which lowers blood sugar but can overshoot, especially between meals or overnight. Meglitinides (repaglinide, nateglinide) work similarly but act faster and wear off sooner, so the risk window is shorter.
Other diabetes medications like metformin, DPP-4 inhibitors, GLP-1 receptor agonists, and SGLT2 inhibitors rarely cause hypoglycemia on their own. They become a concern mainly when combined with insulin or sulfonylureas, or when kidney function declines and the drugs aren’t cleared from the body as quickly. Research shows that roughly 30% of metformin prescriptions and up to 40% of DPP-4 inhibitor prescriptions in people with chronic kidney disease are not adjusted for reduced kidney function, which raises the risk of hypoglycemia and other serious complications.
Antibiotics That Affect Blood Sugar
Fluoroquinolone antibiotics are the most notable infection-fighting drugs linked to hypoglycemia. The FDA issued a safety communication after identifying 56 reports of hypoglycemic coma associated with fluoroquinolones over a roughly 30-year period, plus additional cases in the medical literature. Levofloxacin accounted for the majority of reports (44 cases), followed by ciprofloxacin (12) and moxifloxacin (9). Gatifloxacin was particularly problematic and has been removed from the U.S. market.
Other anti-infective drugs with known hypoglycemia risk include pentamidine (used for certain parasitic and fungal infections), quinine (used for malaria), and trimethoprim-sulfamethoxazole, a widely prescribed antibiotic. If you take any diabetes medication, it’s worth knowing that these antibiotics can amplify the blood sugar-lowering effect.
Heart and Blood Pressure Medications
Beta-blockers like atenolol and propranolol pose a double problem. They can directly contribute to low blood sugar, particularly in overdose, but more importantly, they mask the early warning signs your body uses to alert you that glucose is dropping. Normally, your body releases adrenaline when blood sugar falls, producing noticeable symptoms: a racing heart, trembling, and sweating. Beta-blockers blunt that adrenaline response, so you may not feel anything wrong until blood sugar is dangerously low. Nonselective beta-blockers are of greater concern because they block a wider range of adrenaline receptors, which can also interfere with your body’s ability to recover from a low blood sugar episode on its own.
ACE inhibitors, commonly prescribed for high blood pressure and heart failure, can improve insulin sensitivity by three- to four-fold in people with diabetes. They appear to do this by raising levels of certain signaling molecules (kinins) that increase glucose uptake by muscle tissue and reduce glucose production in the liver. This effect is generally beneficial for blood sugar control, but it can tip into hypoglycemia, especially when combined with sulfonylureas or insulin. Case reports have documented severe, recurrent hypoglycemia from ACE inhibitors even in people without diabetes.
Two heart rhythm medications, cibenzoline and quinidine, are also associated with low blood sugar, though they are used far less commonly today.
Pain Relievers and Anti-Inflammatory Drugs
Indomethacin, a nonsteroidal anti-inflammatory drug used for gout and certain types of arthritis, is listed among medications that can cause hypoglycemia. High-dose aspirin has a more complex relationship with blood sugar. At the doses most people take for pain or heart protection (under 1 gram per day), the effect on glucose is minimal. But at very high doses, around 6 to 7 grams per day in clinical studies, aspirin significantly lowers blood sugar. In one study of people with type 2 diabetes, high-dose aspirin reduced glucose production by the liver by 25% and decreased post-meal blood sugar levels by about 21%. These doses are far beyond what most people take, but they illustrate how salicylates at toxic levels can drive blood sugar dangerously low.
Alcohol’s Role in Medication-Related Hypoglycemia
Alcohol is not a medication, but it is the most common substance that interacts with drugs to cause severe hypoglycemia. When your liver processes alcohol, it shifts its biochemical resources away from producing new glucose, a process called gluconeogenesis. Laboratory research shows ethanol can inhibit this process by up to 66% under experimental conditions. Your liver is the primary organ responsible for maintaining blood sugar between meals and overnight, so when alcohol shuts down that production line while a medication is simultaneously pushing blood sugar lower, the combination can be dangerous.
This risk is highest if you drink on an empty stomach, skip meals, or drink heavily while taking insulin or sulfonylureas. The hypoglycemia can also be delayed, sometimes occurring hours after drinking, which makes it easy to mistake for intoxication rather than a medical emergency.
Who Faces the Greatest Risk
Certain factors make medication-induced hypoglycemia more likely and more dangerous. Reduced kidney function tops the list. Your kidneys clear many drugs from the body, and when they aren’t working at full capacity, medications accumulate to higher-than-intended levels. This is especially relevant for older adults, who often have some degree of kidney decline that may not be obvious without blood tests.
Other risk factors include liver disease (since the liver both metabolizes drugs and produces glucose), irregular eating patterns, increased physical activity without adjusting medication, and taking multiple drugs that each nudge blood sugar downward. A person on insulin who also takes a beta-blocker and an ACE inhibitor, for example, faces compounding risks from three different directions.
Recognizing the Symptoms
The classic pattern of hypoglycemia starts with what are called adrenergic symptoms: shakiness, sweating, a pounding heart, hunger, and anxiety. These are your body’s early alarm system. If blood sugar continues to drop, neuroglycopenic symptoms set in as the brain runs short on fuel: confusion, difficulty speaking, blurred vision, poor coordination, and eventually loss of consciousness or seizures.
Since 1938, clinicians have used a simple framework called Whipple’s triad to confirm hypoglycemia: symptoms consistent with low blood sugar, a measured blood glucose that is low, and relief of those symptoms once blood sugar is corrected. If you take any of the medications discussed above and experience these symptoms, checking your blood sugar (if you have a monitor) and consuming fast-acting carbohydrates like juice or glucose tablets is the standard first response.