7 Insulin Interactions You Should Know About
Key takeaways:
Insulin is a common medication used to treat diabetes. While there are several different types of insulin available, they all have similar interactions with other medications.
Combining insulin with medications like beta blockers, certain antibiotics, and other diabetes medications can increase the risk of low blood glucose. Beta blockers can even hide symptoms of low blood glucose, making the combination more dangerous.
Other medications –– like thiazide diuretics, atypical antipsychotics, and corticosteroids –– can weaken insulin’s effects by raising blood glucose levels.
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Table of contents
Insulin is a life-saving medication. Approximately 6 million people in the U.S. take it on a daily basis to manage diabetes.
If this includes you or a loved one, you know that several types of insulin are available to choose from. They differ from one another in how fast they start working and how long their effects last. The type of insulin that’s recommended for you depends on certain factors, like your blood glucose (sugar) levels, lifestyle habits, and the type of diabetes you have.
While differences between insulins can be complex, they share at least one common feature: interactions with other medications. Often, the result of these interactions is that they lower your blood sugar too much. Sometimes this may just require caution, but other medications should be avoided altogether if you’re using insulin. Below, we’ll discuss seven of the most notable insulin interactions and how you might manage them.
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But keep in mind: This list doesn’t include every possible interaction. Always provide a complete medication list to your healthcare provider and pharmacist so they can check for other possible interactions.
1. Rosiglitazone
Rosiglitazone (Avandia) is an oral medication used to treat Type 2 diabetes. But it has been linked to heart problems in the past, so it’s rarely used in the U.S.
Rosiglitazone and its sister medication, pioglitazone (Actos), work by helping your body respond to insulin better. Pairing either of them with insulin increases the risk for low blood glucose (hypoglycemia). But you might still see pioglitazone taken with insulin as long as you closely track your blood glucose.
This isn’t the case with rosiglitazone and insulin. This combination is not recommended because it can worsen rosiglitazone’s side effects. Specifically, it can worsen edema (how much fluid your body holds on to) and heart failure.
2. Other diabetes medications
It’s important to be cautious when taking insulin with other injectable or oral diabetes medications. Even if these medications work in different ways, they have the same goal — to lower blood glucose. When they’re combined, the effects may be too strong.
Taking insulin with any of the following medications can raise the risk of hypoglycemia:
Sulfonylureas like glipizide (Glucotrol XL)
Amylin analogues like pramlintide (Symlin)
GLP-1 agonists like liraglutide (Victoza) and dulaglutide (Trulicity)
SGLT2 inhibitors like empagliflozin (Jardiance) and canagliflozin (Invokana)
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It’s common to take one or more of these medications with insulin if you have Type 2 diabetes. The combination may help you reach your blood glucose and A1C goals. Your A1C is an average reading of your blood glucose control over the last 2 to 3 months.
Still, it’s important to remember that there’s a higher risk of hypoglycemia compared to taking these medications alone. The best way to handle this concern is to check your blood glucose routinely and keep your healthcare provider in the loop. Also be aware of possible symptoms of hypoglycemia, such as hunger, a fast heartbeat, and feeling shaky.
3. Beta blockers
Beta blockers are medications used to treat certain heart conditions, migraines, and tremors. Some examples include atenolol (Tenormin), carvedilol (Coreg), and propranolol. When taken with insulin, beta blockers can sometimes weaken insulin’s effects. In other cases, they can make its effects too strong — this can lead to hypoglycemia.
Beta blockers can also hide (mask) symptoms of low blood glucose, like fast heart beat, tremors, and irritability. This makes it harder to know if your blood glucose levels are lower than they should be.
If you take both insulin and a beta blocker, it’s important to check your blood glucose regularly, especially since classic hypoglycemia symptoms may be harder to recognize. Make sure you’re able to recognize low blood glucose readings on your glucometer and also when you feel hungry or sweaty. Beta blockers don’t mask these two hypoglycemia symptoms.
4. Certain antibiotics
Fluoroquinolone antibiotics, such as ciprofloxacin (Cipro) and levofloxacin, can cause low blood glucose in their own right. When they’re combined with insulin, the risk of hypoglycemia is even higher. This risk is also greater for older adults with kidney problems who are prescribed the combination.
Sulfa antibiotics, such as Bactrim (sulfamethoxazole/trimethoprim), can also cause low blood glucose when taken with insulin.
If you’re planning to take one or more of these antibiotics while taking insulin, talk to your healthcare provider first. If they’re combined, you may need to track your blood glucose more closely or change your insulin dose.
5. Thiazide diuretics
Thiazide diuretics, like hydrochlorothiazide (Microzide), are used to treat high blood pressure and edema. They’re also known as “water pills.”
These diuretics can affect how your body reacts to insulin. They can weaken its effects. When taken together, the combination can raise your blood glucose and lead to worse diabetes control.
If you’re taking a thiazide diuretic with insulin, make sure to check in with your healthcare provider. They may need to increase your insulin dose depending on how high or low your blood glucose levels are.
6. Medications that raise your blood glucose levels
In addition to thiazide diuretics, many other medications can raise your blood glucose. Atypical antipsychotics and corticosteroids are top examples. These medications can make insulin less effective by making it harder to do its job.
Atypical antipsychotics –– like clozapine (Clozaril) and olanzapine (Zyprexa) –– can change your metabolism and make your body more resistant to insulin. In some cases, this may require a higher insulin dose than normal. You may also see larger amounts of weight gain when insulin and these medications are taken together since they can both cause this side effect.
Similarly, oral corticosteroids like prednisone and dexamethasone can compete with how well insulin works. They can raise your blood glucose, even with short-term use, and cause weight gain with longer use.
When combined with other medications that can raise your blood glucose levels, your healthcare provider may need to watch your blood glucose more closely and adjust your insulin doses as needed.
7. Alcohol
Drinking alcohol can affect your diabetes management. If you have diabetes, drinking any amount of alcohol raises the risk of low blood glucose. That’s because when you drink, your liver is focused on breaking down the alcohol rather than making glucose.
Taking insulin and alcohol together further worsens this risk. Because of this, it’s best to avoid alcohol when taking insulin.
However, since alcohol is a common staple of social gatherings, this isn’t always feasible. If you decide to drink alcohol, make sure to talk to your healthcare provider first. They can suggest tips on ways to drink moderate amounts of alcohol in a safe manner.
The bottom line
Insulin interacts with several medications. These include other diabetes medications, blood pressure medications, and atypical antipsychotics. Corticosteroids, certain antibiotics, and even alcohol can also pose issues. These interactions often cause low blood glucose. But some of them weaken the effects of insulin, which causes high blood glucose.
Proper diabetes management is key to a healthy life. If you’re taking insulin, check with your pharmacist or healthcare provider about any possible interactions that need to be addressed. In most cases, these interactions can be managed by adjusting your insulin dose.
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References
American Diabetes Association. (2015). Fast facts: Data and statistics about diabetes.
Dayabandara, M., et al. (2017). Antipsychotic-associated weight gain: management strategies and impact on treatment adherence. Neuropsychiatric Disease and Treatment.
GlaxoSmithKline plc. (2020). Avandia [package insert].
RemedyRepack Inc. (2022). Insulin aspart [package insert].
Vue, M. H., et al. (2011). Drug-induced glucose alterations part 1: Drug-induced hypoglycemia. Diabetes Spectrum.
Wallach, J. D., et al. (2020). Updating insights into rosiglitazone and cardiovascular risk through shared data: Individual patient and summary level meta-analyses. The British Medical Journal.
