Lantus (insulin glargine) is a brand-name prescription drug used to treat diabetes. As with other medications, Lantus can interact with alcohol and certain other drugs.

An interaction occurs when one substance causes another substance to have a different effect than expected. Most substances that interact with Lantus do so by affecting your blood sugar level, rather than by directly affecting Lantus.

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

In some cases, factors or conditions could prevent your doctor from prescribing Lantus due to the risk of harm. These are known as contraindications. The contraindications of Lantus include:

Current episode of hypoglycemia

You should not take a dose* of Lantus if you currently have hypoglycemia (low blood sugar). Lantus works to lower your blood sugar level, which means it can worsen hypoglycemia if you already have it.

Before you start treatment with Lantus, your doctor may discuss a diabetes care plan with you. Your doctor will likely advise you to check your blood sugar before each dose of Lantus.

If you have hypoglycemia, your doctor can advise you how to treat it. Do not take a dose of Lantus if you currently have hypoglycemia.

If you have hypoglycemia when your Lantus dose is scheduled, your doctor will likely recommend treating the hypoglycemia first. Wait until your blood sugar has returned to its typical level before administering your dose of Lantus.

* Lantus is self-administered as a subcutaneous injection. To learn about Lantus dosages and how it’s used, see this article.

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

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

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

Alcohol can interact with Lantus. It does this by affecting your blood sugar level, rather than by directly interacting with Lantus.

Here are some things to consider if you drink alcohol and are using Lantus:

  • Lantus lowers your blood sugar. Drinking alcohol can also lower your blood sugar, sometimes several hours after drinking. So, drinking alcohol with Lantus can increase your risk of hypoglycemia (low blood sugar). This is especially the case if you drink on an empty stomach.
  • Some of the symptoms of hypoglycemia are similar to those of drinking too much alcohol. For example, both can cause slurred speech, confusion, sleepiness, and trouble with coordination and walking. So, if you drink alcohol with Lantus, it may be hard to know whether you’re experiencing hypoglycemia or have had too much alcohol.
  • If you regularly have more than three alcoholic drinks per day, it can increase your blood sugar. It can also increase your A1C level (a measure of your average blood sugar over the past 3 months). This can make your blood sugar harder to manage. Your doctor may need to increase your dosage of Lantus* or another diabetes medication.

If you drink alcohol, talk with your doctor about the effect that alcohol may have on your blood sugar and your diabetes treatment. Your doctor can recommend whether it’s safe for you to drink alcohol with Lantus. If so, talk with them about how much is safe to drink and when it’s safe to drink.

If you’d like to drink alcohol, the American Diabetes Association recommends doing so only in moderation and with food.

* To learn about Lantus dosages, see this article.

Before you start treatment with Lantus, 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 Lantus interacts with supplements, herbs, or vitamins, see the “Lantus 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 Lantus. Keep in mind that this table doesn’t include all drugs that may interact with Lantus. Some of these interactions are described in detail just below in “Drug interactions in depth.” Most drugs that interact with Lantus do so by affecting your blood sugar level, rather than by directly affecting Lantus.

Drug class or drug nameDrug examplesInteraction result with Lantus
other types of insulin• insulin lispro (Admelog, Humalog)
• insulin aspart (Fiasp, NovoLog)
insulin regular (human) (Humulin R, Novolin R)
can increase the risk of hypoglycemia (low blood sugar) with Lantus*
thiazolidinediones• pioglitazone (Actos)
• rosiglitazone (Avandia)
can increase the risk of certain side effects of both drugs*
other diabetes medicationsdapagliflozin (Farxiga)
glipizide (Glucotrol XL)
• liraglutide (Victoza)
• saxagliptin (Onglyza)
can increase the risk of hypoglycemia with Lantus*
angiotensin-converting enzyme inhibitorsbenazepril (Lotensin)
enalapril (Vasotec)
lisinopril (Zestril)
can increase the risk of hypoglycemia with Lantus*
angiotensin II receptor blockerscandesartan (Atacand)
losartan (Cozaar)
valsartan (Diovan)
can increase the risk of hypoglycemia with Lantus*
beta-blockersatenolol (Tenormin)
nadolol (Corgard)
propranolol (Inderal, Innopran XL)
can increase the risk of hypoglycemia with Lantus*
fibratesfenofibrate (Antara, Lipofen, others)
gemfibrozil (Lopid)
can increase the risk of hypoglycemia with Lantus*
monoamine oxidase inhibitors• isocarboxazid (Marplan)
• phenelzine (Nardil)
• tranylcypromine (Parnate)
can increase the risk of hypoglycemia with Lantus*
salicylates• aspirincan increase the risk of hypoglycemia with Lantus*
HIV protease inhibitors• atazanavir (Reyataz)
• ritonavir (Norvir)
can make Lantus less effective
corticosteroidsdexamethasone
methylprednisolone (Medrol)
prednisone (Rayos)
can make Lantus less effective
atypical antipsychoticsolanzapine (Zyprexa)
quetiapine (Seroquel)
• clozapine (Clozaril)
can make Lantus less effective
sympathomimetics• amphetamine/
dextroamphetamine (Adderall)
methylphenidate (Ritalin)
• phenylephrine
• pseudoephedrine
can make Lantus less effective
disopyramide (Norpace)can increase the risk of hypoglycemia with Lantus*
fluoxetine (Prozac)can increase the risk of hypoglycemia with Lantus*
lithium (Lithobid)can increase the risk of hypoglycemia with Lantus* or make Lantus less effective

* To learn about this side effect of Lantus, see this article.

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

Thiazolidinediones

Thiazolidinediones are a type of diabetes medication. If you have type 2 diabetes, your doctor may sometimes prescribe Lantus with a thiazolidinedione.

Interaction result. Using Lantus with a thiazolidinedione can increase your risk of hypoglycemia (low blood sugar). It can also increase your risk of heart failure.

Interaction explained. Lantus and thiazolidinediones both lower your blood sugar level. Taking these medications in combination may lower your blood sugar level too much, which could cause hypoglycemia.

Lantus and thiazolidinediones can both also cause fluid buildup. Taking them in combination may cause too much fluid buildup. This could cause heart failure or worsen heart failure if you already have it.

Examples of thiazolidinedione drugs. Here are some thiazolidinedione drugs that may interact with Lantus:

Steps you or your doctor may take. If you are prescribed Lantus with a thiazolidinedione drug, your doctor may recommend monitoring your blood sugar more often. Talk with your doctor if you have episodes of hypoglycemia while taking these medications. Your doctor may need to adjust your dosage of one or both medications to lower your risk of hypoglycemia. (To learn about Lantus dosages, see this article.)

Your doctor will also likely monitor you for new or worsening symptoms of heart failure. These can include shortness of breath; swelling of your legs, ankles, or feet; and sudden weight gain. Talk with your doctor if you develop any of these symptoms.

If you develop new or worsening heart failure while taking both drugs, your doctor will likely reduce your dosage of the thiazolidinedione. Or they may have you stop taking the thiazolidinedione altogether.

Beta-blockers

Beta-blockers are used to treat high blood pressure, angina (chest pain), and arrhythmia (irregular heartbeat). Some are also used to help reduce symptoms of anxiety or an overactive thyroid. Some beta-blockers are also prescribed to treat heart failure.

Interaction result. Using Lantus with a beta-blocker can hide some of the symptoms you may have with an episode of hypoglycemia.

Plus, using Lantus while taking certain beta-blockers may increase your risk of hypoglycemia. It could also increase the time it takes to recover from a hypoglycemia episode.

Interaction explained. Lantus can sometimes cause hypoglycemia. Symptoms you may have with an episode of hypoglycemia include tremors, fast heart rate, and heart palpitations. Beta-blockers help reduce these symptoms. So, if your blood sugar drops too low while you’re taking a beta-blocker, you may be less aware of it. This could increase your risk of severe hypoglycemia.

Some beta-blockers, such as propranolol, can increase the ability of insulin to lower blood sugar. This can increase your risk of hypoglycemia. It can also increase how long it takes to recover from an episode of hypoglycemia.

Examples of beta-blocker drugs. Here are some beta-blockers that may interact with Lantus:

Steps you or your doctor may take. If you use Lantus and take a beta-blocker, your doctor may recommend that you check your blood sugar more often. If needed, your doctor may reduce your dosage of Lantus to lower your risk of hypoglycemia. (To learn about Lantus dosages, see this article.)

However, beta-blockers don’t hide all the possible symptoms of hypoglycemia. For example, you may still have symptoms such as headache, dizziness, nervousness, irritability, or hunger if your blood sugar drops too low. If you have symptoms that might be caused by low blood sugar, check your blood sugar right away.

Corticosteroids

Corticosteroids (sometimes called steroids*) are drugs that reduce inflammation. They’re used to treat many different conditions, including asthma and arthritis.

Interaction result. Using Lantus while taking a corticosteroid could make Lantus less effective.

Interaction explained. Corticosteroids can increase your blood sugar. So, if you use Lantus while taking a corticosteroid, you may need a higher dosage of Lantus than you typically would to manage your blood sugar. (To learn about Lantus dosages, see this article.)

Examples of corticosteroid drugs. Here are some corticosteroids that may interact with Lantus:

Steps you or your doctor may take. If you use Lantus and take a corticosteroid, your doctor will likely recommend that you check your blood sugar more often. If needed, your doctor may increase your Lantus dosage to help manage your blood sugar.

* Note that these drugs are not anabolic steroids.

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

Lantus and supplements

It’s possible for drugs to interact with supplements such as vitamins and herbs.

Lantus and herbs

There are no specific reports of herbs interacting with Lantus. However, that doesn’t mean herbal interactions won’t occur or be recognized in the future. Because of this, it’s important to check with your doctor or pharmacist before taking any of these products during Lantus treatment.

Lantus and vitamins

There are no specific reports of vitamins interacting with Lantus. However, that doesn’t mean vitamin interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist before taking any vitamin product with Lantus.

Lantus and food

There were no reports of food interactions with Lantus. If you’d like to learn more about eating certain foods during treatment with Lantus, talk with your doctor.

Lantus and vaccines

There are no specific reports of vaccines interacting with Lantus. However, that doesn’t mean vaccine interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist before getting any vaccines while using Lantus.

Lantus and lab tests

There are no specific reports of Lantus interacting with lab tests. However, that doesn’t mean lab test interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist if you need to have any lab tests while using Lantus.

LANTUS AND CANNABIS OR CBD

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

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

Certain medical conditions and other factors may increase the risk of interactions with Lantus. Before you use this drug, be sure to talk with your doctor about your health history. Lantus 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 Lantus include:

  • Low potassium level. Lantus can sometimes lower the potassium level in your blood. If this level is already low, Lantus could lower it even further. If you have low potassium or an increased risk of this condition, your doctor may monitor your potassium while you’re using Lantus.
  • Pregnancy. There aren’t enough clinical trials of Lantus in pregnant people to know for sure how safe it is to use during pregnancy. However, doctors typically recommend using insulin to treat diabetes during pregnancy. This includes type 1 and type 2 diabetes, as well as gestational diabetes (diabetes that develops during pregnancy). Lantus is a type of insulin. If you need treatment for diabetes during pregnancy, talk with your doctor about whether Lantus is the right type of insulin for you. If you were using Lantus before becoming pregnant, your doctor may need to adjust your dosage* during your pregnancy.
  • Breastfeeding. Doctors typically consider Lantus to be safe during breastfeeding. The drug may pass into breast milk. However, it’s not known to cause side effects in a child who’s breastfed. Insulin is a natural component of breast milk. So, insulin such as Lantus isn’t likely to cause harm during breastfeeding. If you use Lantus while breastfeeding, your doctor may need to adjust your dosage.
  • Allergic reaction. If you’ve had an allergic reaction† to Lantus or any of its ingredients, your doctor will likely not prescribe Lantus. Using the drug could cause another allergic reaction. You can ask your doctor about other treatment options that may be better for you.
  • Current episode of hypoglycemia. If you’re having an episode of hypoglycemia† when your Lantus dose is scheduled, do not administer your dose of Lantus.* First, treat the hypoglycemia according to the diabetes care plan recommended by your doctor. Wait until your blood sugar has returned to its typical level before administering your dose of Lantus.

* To learn about Lantus dosages, see this article.
† For more details about this interaction, see the “When to avoid Lantus” section above.

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

Can I take pain relievers with Lantus?

Yes, it’s generally safe to take certain pain relievers with Lantus. These include acetaminophen (Tylenol) and ibuprofen (Advil, Motrin).

However, be sure to ask your doctor or pharmacist to recommend a product that’s right for you. Some pain relievers contain several ingredients. Some ingredients may affect your blood sugar level and could interact with Lantus.

For example, aspirin may increase your risk of having low blood sugar with Lantus. On the other hand, decongestant drugs, such as phenylephrine or pseudoephedrine, may increase your blood sugar. This could make Lantus less effective.

If you have questions about taking pain relievers with Lantus, talk with your doctor or pharmacist.

If I take another medication by injection, is it still safe for me to use Lantus?

Yes, it’s generally safe to use Lantus with other injectable medications if your doctor recommends it.

That said, you should avoid injecting more than one medication into the same spot. For example, if you need to inject Lantus and another medication, you should use a different injection site for each dose. So, if you inject Lantus into your left thigh, choose a part of your body other than your left thigh to inject your other medication. This decreases your risk of injection site reactions,* including lipodystrophy (skin thickening near the injection site).

If you need to administer Lantus and another injectable medication, talk with your doctor or pharmacist to learn more about how to safely give your injections.

* To learn more about this side effect of Lantus, see this article.

You can take certain steps to help prevent interactions with Lantus. 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, take cannabis, or use CBD.
  • 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 Lantus label and other paperwork that may come with the drug. The label may have colored stickers that mention an interaction. The paperwork, sometimes called the medication guide or patient package insert, may contain details about interactions. (If Lantus 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 Lantus by using it exactly as your doctor prescribes.

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

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.