Lantus (insulin glargine)
Lantus Vial
Insulin Glargine
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Prescription Required.

Product of Canada.

Shipped from Canada.

Prescription Required.Product of Canada.Shipped from Canada.

Lantus (insulin glargine)

What is Lantus (insulin glargine)?

Lantus (insulin glargine), available in its vial form, is a long-acting insulin that is used once daily to assist patients in managing their type 1 diabetes (in those who are adults or children ages six years and older) or type 2 diabetes (in adults only). This medication may be used alongside short-acting insulins as a part of a patient’s insulin regimen, but it should not be used for the treatment of diabetic ketoacidosis.

How is Lantus Used?

Just as with other types of insulin, Lantus must be administered via subcutaneous injection, meaning that the medication will need to be injected underneath the patient’s skin. As a long-acting form of insulin, this medication may be used alongside other fast-acting insulin to help manage a patient’s blood glucose levels throughout the day.

Typically, Lantus is injected once per day, and the dosage is determined by the patient’s prescribing physician based on a variety of health-related factors.


Any unopened vials of this medication should be stored in a refrigerator and be kept in a temperature range of 36°F (2°C) to 46°F (8°C) until it is ready to be used. Unopened vials may be stored in a refrigerator for as long as necessary until the expiration date listed on the vial has been reached. After this date has passed, the vial and its content should be safely disposed of and not used.

Once a vial of this medication has been opened, it may be stored at room temperature or in the refrigerator, but it should be disposed of regardless of storage method after 28 days have passed since opening it.

No form of insulin should ever be frozen, and this medication should be protected from both sunlight and excessively high temperatures. This medication should also not be used if it is discolored, cloudy, or has any clumps present within the vial. Lantus does not require shaking or swirling before use.

Keep this medication out of the reach of children at all times.

Lantus and any other medications should not be disposed of in the household trash or in wastewater, such as being flushed down the toilet or poured down the sink. Please consult with your physician or local pharmacy regarding the safe and proper disposal of any unused medication.


Lantus is prescribed to manage type 1 and type 2 diabetes in adults and type 1 diabetes in children that are six years of age and older.

How Does Lantus Work?

This medication serves as a replacement for the insulin produced by a patient’s body, and it manages an individual’s diabetes by lowering their blood glucose levels.

Lantus is able to lower a patient’s blood glucose levels by decreasing the liver’s ability to make additional blood glucose, helping the fat and muscle cells in the patient’s body to take up more glucose that may be present in the blood, and helping the patient’s body to break down the glucose in the blood rather than breaking down the proteins and fats that are present.


This medication comes in a 10 mL vial with 100 units of insulin glargine per each mL of solution.

The dosage of this medication required for treatment will vary based on the patient’s current level of insulin production as well as any additional medications they may be using. The required dosage may also vary based on additional factors, such as the patient’s age, weight, and any preexisting medical conditions they may have.

Patients should use this medication exactly as instructed by their physician, especially following any directions related to the timing of injection in relation to their meal times, as this is a significant factor in ensuring the safety and efficacy of this exogenous insulin and properly managing their condition.


If an overdose is suspected or has occurred, patients should contact their physician or local Poison Control Center. If severe symptoms arise after injecting too much of this medication, patients should seek emergency medical attention as soon as possible.

Injecting too much insulin can cause hypoglycemia to occur. In mild instances, orally consuming carbohydrates may be sufficient to increase the patient’s blood glucose levels and resolve the condition. Severe hypoglycemia can cause neurological impairment, seizures, or even death. These instances will require intravenous glucose administration or the use of glucagon. After such an episode, monitoring and observation of the affected individual are often required to ensure that control over their diabetes has been effectively restored and that they receive the appropriate modification in their insulin dosage.

Side Effects

The most common side effects of taking Lantus are as follows:

  • hollowing of the skin at the injection site
  • hypoglycemia (low blood glucose levels)
  • itchiness
  • mild rash on the skin
  • thickening of the skin at the injection site

Some of the following side effects may occur and should be reported to your doctor if they occur. Seek emergency medical attention as soon as possible if you develop any of the following symptoms after using this medication:

  • breathing difficulties
  • constipation
  • cramps in the legs
  • feeling lightheaded
  • feeling limp
  • fluttering sensation in the chest
  • increased urination
  • increased thirst
  • irregular heart rhythm
  • numbness
  • rapid heart rate
  • rapid weight gain
  • shortness of breath
  • skin rash that itches and covers the entire body
  • swelling and redness at the site of injection
  • swelling of the ankles or feet
  • swelling of the throat or tongue
  • tingling sensation
  • weakness in the muscles

Warnings & Precautions

Allergic Reactions

As with any medication, some patients may experience an allergic reaction when using this medication. Patients that experience a hypersensitive reaction, including serious symptoms such as anaphylaxis, should discontinue their use of this insulin and seek emergency medical assistance as soon as possible.

Changes in a Patient’s Insulin Regimen

Any changes made to a patient’s insulin regimen may result in a temporary loss of control over their diabetes, which may result in blood glucose levels that are too low or too high. Any individuals that require changes in their insulin regimen should monitor their blood glucose levels more closely until they are sure of how the changes in their medications have affected the overall management of their diabetes.


This medication has been shown to be both safe and effective in children between the ages of 6 and 15 years who have been diagnosed with type 1 diabetes. However, caution should be exercised regarding the dosage and frequency of use of this medication in pediatric patients due to this age group being more sensitive to the effects of injected insulin, and this has resulted in a higher prevalence of severe hypoglycemia occurring in these individuals.

Elderly Patients

This medication has been shown to be just as safe and effective in geriatric patients as in all of the age groups below 65 years. However, due to the risks of sensitivity to insulin that may result in hypoglycemia occurring, elderly patients should have their dosage of Lantus carefully monitored and adjusted as needed to ensure the safest and most effective dose possible without lowering their blood glucose levels too sharply.


One of the most common side effects of using insulin medications is hypoglycemia (low blood sugar levels). When a patient’s blood glucose levels drop too low, this may result in impaired concentration and difficulty reacting quickly in some situations. Additionally, dangerously low levels of glucose in the blood may also cause seizures, become life-threatening, and may even become fatal. The onset of hypoglycemia may also be rapid in nature and have varying symptoms amongst individuals. Those who use beta-blockers, have diabetic neuropathy, or have a long history of diabetes may be less likely to notice the symptoms of hypoglycemia occurring when using this medication.


The use of insulin can result in changes within the body that may lead to the development of hypokalemia. If left untreated, this can result in issues such as ventricular arrhythmia, respiratory paralysis, or even death. Patients using insulin therapy, especially those also using medications to manage potassium levels, should have their potassium levels monitored as needed for this condition.

Liver Function

Although no formal studies determining the safety and efficacy of this medication in those who have impaired hepatic function have been performed, it has been noted that patients with liver impairment may require dosage modifications as well as additional monitoring of their blood glucose levels during treatment.

Kidney Function

Patients with impaired renal function may require dosage changes and additional monitoring of their blood glucose levels while using this medication, as some studies have indicated higher levels of insulin being present in those who have kidney failure. However, no formal studies on the effect of impaired kidney function and Lantus itself have been conducted.

Pregnancy and Breastfeeding

Despite studies related to Lantus use during pregnancy, there have been no definitive links between the use of this medication and any adverse fetal-related outcomes. However, patients that have diabetes that is not well-managed during pregnancy have been shown to have numerous potential health risks for themselves as well as the developing child. Pregnant patients without sufficient control over their diabetes have a high risk of preterm delivery, birth defects, preeclampsia, diabetic ketoacidosis, miscarriage, stillbirth, and complications during delivery.

As endogenous insulin is already present in the breast milk produced by humans, the presence of this exogenous insulin medication is often deemed safe to use while breastfeeding as the benefits of using such often outweigh the risks of the patient having diabetes that is not well-controlled.

Syringes and Needles Should Not Be Shared

Patients using these vials should never share any syringes or needles with another individual nor re-use any syringes or needles, as this carries a significant risk of transmitting various pathogens that may result in infection or illness.

Drug Interactions

Speak to your doctor about any medications or herbal supplements you are currently taking before beginning treatment with this medication. Discuss any concerns you may have with your doctor or a trusted pharmacist.

The following medications and substances are known to interact with Lantus:

  • ACE inhibitors
  • alcohol
  • anabolic steroids
  • antipsychotics
  • aripiprazole
  • ASA
  • atenolol
  • beta-blockers
  • birth control pills
  • bismuth subsalicylate
  • bromocriptine
  • buserelin
  • ciprofloxacin
  • citalopram
  • clozapine
  • corticosteroids
  • danazol
  • decongestants
  • diuretics
  • duloxetine
  • enalapril
  • epinephrine
  • estrogens
  • everolimus
  • fluoxetine
  • gliclazide
  • glucagon
  • glyburide
  • growth hormone
  • haloperidol
  • HIV protease inhibitors
  • hydrochlorothiazide
  • lisinopril
  • metoprolol
  • mifepristone
  • niacin
  • norfloxacin
  • octreotide
  • olanzapine
  • oral diabetes medications
  • paroxetine
  • phenelzine
  • phenytoin
  • pindolol
  • pioglitazone
  • prednisone
  • prednisolone
  • progesterone
  • propranolol
  • pseudoephedrine
  • quetiapine
  • quinine
  • quinolone antibiotics
  • ramipril
  • risperidone
  • rosiglitazone
  • salicylates
  • selective serotonin reuptake inhibitors (SSRIs)
  • sertraline
  • sirolimus
  • somatropin
  • sotalol
  • sulfa antibiotics
  • sulfadiazine
  • sulfamethoxazole
  • tacrolimus
  • testosterone
  • thyroid replacement therapy
  • tranylcypromine
  • triptorelin

Alternative Medications

For patients who are unable to take Lantus or are experiencing significant adverse side effects, alternative medications may be used to treat some of the associated conditions for which this medication is commonly prescribed:

  • dulaglutide (Trulicity)
  • insulin aspart (NovoLog)
  • insulin detemir (Levemir)
  • insulin glargine (Basaglar, Rezvoglar, Semglee, Toujeo)
  • insulin lispro (Humalog)
  • linagliptin (Tradjenta)
  • metformin (Fortamet, Glucophage, Glumetza, Riomet)
  • saxagliptin (Onglyza)
  • semaglutide (Rybelsus)
  • sitagliptin (Januvia)

Frequently Asked Questions

This medication is a man-made insulin that is long-acting and used to manage high blood glucose levels in adults as well as children above the age of 6 years.

This medication comes in a vial and should be subcutaneously injected underneath the patient’s skin.

Weight gain may occur in individuals using any type of insulin to manage their diabetes.

Any serious side effects that occur when using this medication should be reported to the patient’s prescribing physician as soon as possible. Emergency medical attention should be sought if any of the following side effects occur: breathing difficulties, rapid heartbeat, a full-body rash, extreme confusion or dizziness, extreme drowsiness, or swelling of the throat, tongue, or face.

This medication should not be mixed with other insulin without discussing this combination with your prescribing physician beforehand. Patients should discuss all insulin use, as well as the use of any additional medications to manage diabetes, with their physician to determine the safest and most effective dosage size and frequency of Lantus for treatment.

Any patients using a mealtime insulin should discuss any necessary changes with their doctor when adding Lantus to their diabetes management regimen. Some changes to mealtime or other insulin being used may be required in some individuals.

This medication functions as a replacement for the body’s insulin, managing an individual’s diabetes by lowering their blood glucose levels. It does this by reducing the liver’s ability to make additional blood glucose, assisting a patient’s fat and muscle cells in taking up glucose in the blood, and encouraging the body to break down the glucose in the blood rather than proteins and fats.

Any unopened vials of this medication should be stored in a refrigerator between 36°F (2°C) and 46°F (8°C). After a vial of this medication has been opened, it may be stored at room temperature or in the refrigerator, but it should be disposed of regardless of storage method after 28 days have passed since opening it.

It has not been confirmed whether or not this medication is linked to patients developing certain cancers, but long-term use appears to have a link to some patients developing breast cancer. However, studies have shown that diabetes is also linked to an increased risk of cancer in some individuals, so additional studies are needed to determine the exact risks associated with Lantus.

If a patient misses a dose of this medication, it should be taken as soon as they realize it’s been missed. However, if the next scheduled dose is occurring soon, the missed dose should simply be skipped, with the next dose occurring as scheduled.

Some individuals who tolerate this medication well may need to continue to use it for the long term to help manage their diabetes.

This medication typically begins to affect a patient’s blood glucose levels within about 90 minutes to 2 hours after being injected.

Some of the milder and more common side effects of using this medication include headaches, edema, weight gain, upper respiratory infections, or experiencing a reaction at the site of injection.

The active ingredient in Lantus is insulin glargine. The inactive ingredients also present in the vials include the following: water, polysorbate 20, glycerol 85%, m-cresol, and zinc.

This medication may interact with the following: certain antidepressants and antipsychotics, HIV medications, birth control pills, additional diabetes medications, cholesterol and thyroid medications, blood pressure medications, and corticosteroids.

This medication is prescribed to treat both type 1 and type 2 diabetes in adults as well as type 1 diabetes in children six years old and above.

If any overdose of this medication has occurred or is suspected, the individual who has received too much of this medication should contact their physician or their local Poison Control Center. However, if the individual that has overdosed experiences significant side effects, especially those indicating a drop in potassium or blood glucose levels, emergency medical attention should be sought immediately.