Humalog interactions: Alcohol, medications, and other factors

Humalog (insulin lispro) is a brand-name prescription drug used to treat diabetes. As with other medications, Humalog can interact with alcohol and certain other drugs. It can also interact with some supplements. An interaction occurs when one substance causes another substance to have a different effect than expected.

Humalog comes in different forms, and they have similar interactions. The forms are:

• Humalog (insulin lispro)
• Humalog Mix 50/50 (50% insulin lispro protamine and 50% insulin lispro)
• Humalog Mix 75/25 (75% insulin lispro protamine and 25% insulin lispro)

These drugs may have similar interactions, but there may also be some differences. Talk with your doctor to learn more about interactions of Humalog Mix 50/50 or Humalog Mix 75/25.

For details about Humalog’s interactions, keep reading. For additional information about Humalog, including details about its uses, see this article.

Some factors or conditions could prevent your doctor from prescribing Humalog due to the risk of harm. These are known as contraindications. The contraindications of Humalog include:

Having hypoglycemia

Humalog works to lower your blood sugar levels, which helps manage your diabetes. If you already have hypoglycemia (low blood sugar), taking Humalog can lower your blood sugar even further. This can be serious or even life threatening. Due to this risk, doctors typically will not prescribe Humalog to people with hypoglycemia.

Having had an allergic reaction to Humalog or any of its ingredients

If you have had an allergic reaction to Humalog or any of its ingredients, your doctor will likely not prescribe Humalog. Using the drug could cause another allergic reaction. You can ask them about other treatments that may be more suitable for you.

Note: Before you start treatment with Humalog, it’s important to tell your doctor if these contraindications apply to you. They can determine whether to prescribe Humalog.

Consuming alcohol while using Humalog may increase your risk of side effects from Humalog or decrease the effects of the drug.

Also, alcohol may make managing your blood sugar levels more difficult. In fact, alcohol can cause blood sugar levels to become too high or too low. So, if you already have diabetes, drinking alcohol may make your condition harder to manage.

If you’d like to drink alcohol during your diabetes treatment, talk with your doctor. They can help determine how much alcohol, if any, may be safe for you. In addition, they may recommend more frequent monitoring of your blood sugar levels when you are drinking alcohol.

Before you start treatment with Humalog, tell your doctor and pharmacist which prescription, over-the-counter, and other medications you take. By sharing this information with them, you may help prevent possible interactions. (To learn whether Humalog interacts with supplements, herbs, or vitamins, see the “Humalog and other interactions” section below.)

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Here’s a table of drugs that can interact with Humalog. Keep in mind that this table doesn’t include all drugs that may interact with Humalog. For more detailed descriptions of some of these interactions, see “Drug interactions in depth” below.

* For details about Humalog’s side effects, see this article.

Here’s a closer look at certain drug interactions of Humalog.

Other diabetes medications

Your doctor may recommend that you take other diabetes medications in addition to Humalog to help manage your diabetes.

Interaction result. Taking other diabetes medications and Humalog together may increase your risk of side effects from both drugs. This may include hypoglycemia (low blood sugar).

Interaction explained. If you take other diabetes drugs with Humalog, you can develop hypoglycemia. This is because both drugs work to decrease your blood sugar. And taking more than one drug to decrease your blood sugar levels may cause your blood sugar to become too low. This can be a serious and even life threatening condition.

Examples of other diabetes drugs. Here are some other diabetes medications that may interact with Humalog:

• pramlintide (Symlin)
• sitagliptin (Januvia)
• metformin (Fortamet)
• semaglutide (Ozempic)
• glipizide (Glucotrol)
• other forms of insulin, such as insulin detemir (Levemir)

Steps you or your doctor may take. Your doctor will recommend monitoring your blood sugar throughout your diabetes treatment. If you develop symptoms of hypoglycemia, such as sweating or dizziness, check your blood sugar. Your doctor can recommend the best way to increase your blood sugar if it becomes too low. This may include eating a hard candy or drinking some juice.

If you have questions about taking other diabetes drugs with Humalog, talk with your doctor.

Diuretics

It’s possible for diuretic drugs (also called “water pills”) to interact with Humalog. These medications can be used to get rid of excess fluid or to help manage blood pressure.

Interaction result. Taking a diuretic drug along with Humalog may make Humalog less effective.

Interaction explained. If you take Humalog with a diuretic drug, Humalog may not manage your blood sugar levels as well as it should. This may prevent Humalog from lowering your blood sugar.

Examples of diuretic drugs. Here are some diuretics that may interact with Humalog:

• hydrochlorothiazide
• spironolactone (Aldactone)
• furosemide (Lasix)

Steps you or your doctor may take. If you’re currently taking a diuretic, tell your doctor before taking Humalog. They may recommend monitoring your blood sugar more often to be sure that Humalog is working for you. Sometimes, they may recommend adjusting your Humalog dose to ensure the drug is working to manage your diabetes. (For details about Humalog’s dosage, see this article.)

For more information about taking diuretics with Humalog, talk with your doctor.

Thiazolidinediones

Thiazolidinediones (TZDs) can interact with Humalog. Similarly to Humalog, TZDs help manage blood sugar levels in people with diabetes.

Interaction result. Taking a TZD with Humalog may increase the risk of heart failure occurring. This drug combination may also increase the risk of low blood sugar. This is a side effect of both TZDs and Humalog.

Interaction explained. The combination of TZDs with Humalog can cause heart failure or worsen existing heart failure. This is because, when used with insulin, TZDs, such as Humalog, may increase your risk of swelling. This can cause heart failure or make your heart failure worse. Also, similar to Humalog, TZDs are used to lower blood sugar. So, taking both drugs together could lower your blood sugar too much. This could be a serious side effect.

Examples of TZD drugs. TZDs that may interact with Humalog include pioglitazone (Actos) and rosiglitazone (Avandia).*

Steps you or your doctor may take. If you have heart failure, your doctor will likely monitor you more often for worsening symptoms while you take Humalog and a TZD. Worsening symptoms of heart failure may include trouble breathing or sudden weight gain. Sometimes, your doctor may recommend adjusting your dose of TZD or Humalog or stopping one medication. They may also recommend a different treatment plan for you. (For details about Humalog’s dosage, see this article.)

If you are concerned about taking TZDs with Humalog, talk with your doctor.

* The drug manufacturer of Avandia does not recommend using Avandia with insulin, such as Humalog.

Humalog may have other interactions, such as with supplements or foods. It’s not known to interact with vaccines or lab tests. You’ll find details below. Keep in mind that the following information does not include all other possible interactions with Humalog.

Humalog interactions with supplements

Before you start treatment with Humalog, tell your doctor and pharmacist which supplements, herbs, and vitamins you take. By sharing this information with them, you may help prevent possible interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Humalog interactions with herbs

Tell your doctor about any herbal supplements that you take before starting Humalog. Certain herbs, such as garlic supplements, may affect your blood sugar level. For example, garlic supplements may lower your blood sugar. This can increase your risk of having hypoglycemia (low blood sugar) while taking Humalog.

Your doctor can help determine if Humalog is safe to take with herbal supplements.

Humalog interactions with vitamins

It’s possible for Humalog to interact with certain vitamins, such as vitamin B3 (also called niacin). Vitamin B3 may cause hyperglycemia (high blood sugar). Taking this vitamin with Humalog may make it harder for you to manage your diabetes.

Talk with your doctor before taking any vitamins during Humalog treatment. They can help make sure that the combination is safe.

Humalog interactions with food

Green tea can affect your blood sugar levels. Specifically, green tea can lower your blood sugar, which can increase the risk of hypoglycemia occurring. Humalog can also increase the risk of hypoglycemia. So, this combination may increase the risk further.

If you’d like to drink green tea while taking Humalog, talk with your doctor to see how much, if any, may be safe for you.

Humalog and vaccines

Humalog isn’t known to interact with any vaccines. You can stay up-to-date on your vaccines by talking with your doctor or pharmacist.

Humalog and lab tests

Humalog isn’t known to interact with lab tests. If you need a lab test done, tell your doctor about any medications you take.

HUMALOG AND CANNABIS OR CBD

Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have not been specifically reported to interact with Humalog. However, as with any drug or supplement, talk with your doctor before using cannabis in combination with Humalog. The impact of cannabis may affect how well you stick to your Humalog treatment plan.

Note: Cannabis is illegal at a federal level but is legal in many U.S. states to varying degrees.

Certain medical conditions and other factors may increase the risk of interactions with Humalog. Before you take this drug, be sure to talk with your doctor about your health history. Humalog may not be the right treatment option if you have certain medical conditions or other factors affecting your health.

Health conditions or factors that might interact with Humalog include:

• Liver problems. If you have liver problems, tell your doctor before taking Humalog. Liver problems may increase your risk of developing hypoglycemia. And taking Humalog may increase your risk of this even further. Your doctor can help determine if Humalog is a safe treatment option for you.
• Low blood potassium levels. It’s possible for Humalog to cause low blood potassium levels. If you already have low potassium levels, taking Humalog may lower them further. Your doctor may recommend correcting your potassium levels before taking Humalog. They may also recommend monitoring your blood potassium levels throughout your treatment with Humalog.
• Kidney problems. Tell your doctor about any kidney problems that you have before taking Humalog. If you have kidney problems, you may have an increased risk of hypoglycemia. Taking Humalog can also cause hypoglycemia. So, if you have kidney problems, your doctor can help determine if Humalog is safe for you.
• Heart problems. Before starting Humalog, tell your doctor if you’re taking another diabetes drug called a thiazolidinedione. If you have heart problems, such as heart failure, this drug combination may worsen your heart condition. In this case, your doctor may monitor you more often for symptoms of worsening heart failure. Symptoms may include shortness of breath or swelling of the legs or feet. Your doctor can determine if this combination of medications is safe for you if you have heart failure.
• Pregnancy. At this time, it is unknown whether it’s safe to take Humalog during pregnancy. There currently haven’t been enough clinical trials on pregnant people to determine if the drug may be safe. Animal studies did not show an increased risk of congenital anomalies (commonly known as birth defects) when pregnant animals were given the drug. However, animal studies don’t always indicate what may happen in humans. If you’re pregnant or planning to become pregnant, talk with your doctor about the best treatment plan for you.
• Breastfeeding. It’s not known if it’s safe to take Humalog while breastfeeding. It is unknown whether the drug passes into breast milk or what effects it may have on a breastfed child. If you’re breastfeeding, talk with your doctor before taking Humalog.
• Allergic reaction. If you’ve had an allergic reaction to Humalog or any of its ingredients, your doctor will likely not prescribe Humalog. Using the drug could cause another allergic reaction. You can ask them about other treatments that may be more suitable for you.

Here are some frequently asked questions about Humalog and possible interactions.

Is it safe for me to take Humalog along with long-acting insulin products?

Yes, it’s usually safe for you to take Humalog along with a long-acting insulin. This type of insulin helps manage blood sugar levels throughout the day.

For people with diabetes, doctors will often recommend using a rapid-acting insulin, such as Humalog, along with a long-acting insulin. (Rapid-acting insulin helps manage your blood sugar after having a meal.) This combination of insulin can help manage your blood sugar throughout the day.

Examples of long-acting insulins that your doctor may recommend taking with Humalog include:

• insulin glargine (Lantus, Basaglar, Toujeo)
• insulin detemir (Levemir)
• insulin degludec (Tresiba)

However, using a long-acting insulin along with Humalog may increase your risk of hypoglycemia (low blood sugar) occurring. So, if you take a combination of insulin medications, your doctor may recommend more frequent monitoring of your blood sugar.

If you have additional questions about taking Humalog along with long-acting insulin products, talk with your doctor or pharmacist.

Are Humalog and NovoLog interchangeable?

No, Humalog and NovoLog are not interchangeable. Both Humalog and NovoLog are rapid-acting insulins. These medications help manage blood sugar levels that may increase after a meal.

However, Humalog and NovoLog contain two different active drugs. Humalog contains the active ingredient insulin lispro, while NovoLog contains insulin aspart. So, although these medications may work in similar ways, they are not interchangeable. To learn more about how these drugs compare, see this article.

If you’re taking either NovoLog or Humalog and you’re having side effects or a reaction from the drug, talk with your doctor. They may recommend switching from NovoLog to Humalog or vice versa. Since these drugs aren’t exactly the same, your body may respond differently to either medication.

You can take certain steps to help prevent interactions with Humalog. Your doctor and pharmacist are key resources, so reach out to them before starting treatment. For example, you should plan to do the following:

• Let them know if you drink alcohol or use cannabis.
• Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
• Create a medication list, which your doctor and pharmacist can help you fill out.

It’s also important to read the Humalog label and other paperwork that may come with the drug. The label may have colored stickers that mention an interaction. And the paperwork, sometimes called the medication guide or patient package insert, may contain details about interactions. (If Humalog doesn’t come with paperwork, you can ask your pharmacist to print a copy.) If you need help reading or understanding this information, ask your doctor or pharmacist.

You can also help prevent interactions with Humalog by using it exactly as your doctor prescribes.

Besides learning about interactions, you may want to find out more about Humalog. These resources might help:

• Overview of Humalog. For a general overview of Humalog, you can see this article.
• Side effects. If you’re interested in the side effects of Humalog, see this article. Another option is to refer to the prescribing information of Humalog, Humalog Mix 50/50, and Humalog Mix 75/25.
• Dosage specifics. To learn about the dosage of Humalog, see this article.
• Drug comparison. Learn about how Humalog compares with Humulin N and NovoLog.
• Facts about diabetes. For information about type 1 or type 2 diabetes, see our diabetes hub. You can also refer to our list of diabetes articles.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.