Invokana Insights: 10 Drug Facts You Should Know
Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on April 10, 2021.
1. Invokana Is Canagliflozin: How Does It Work?
- These drugs are hypoglycemics (drugs used to lower blood sugar) in patients with type 2 diabetes. The SGLT2 inhibitors block the kidney from reabsorbing sugar (glucose).
- In turn, you eliminate more glucose in your urine which lowers your blood sugar levels.
- Invokana is also associated with reductions in blood pressure and weight loss, and was the first SGLT2 inhibitor FDA-approved in March 2013.
2. Invokana: When to Start?
When someone is first diagnosed with type 2 diabetes, they will not typically start with Invokana alone as an initial treatment.
Invokana is usually added on to other diabetes treatments, such as metformin, sulfonylureas, or insulin, as an "adjunct", when a patient no longer responds or if the blood sugar level is too high at the outset. Invokana is commonly combined with metformin.
The SGLT-2 inhibitor drugs, which come as oral tablets, are sold as individual agents and in combination with other diabetes drugs. Examples include:
- Invokana (canagliflozin)
- Invokamet, Invokamet XR (canagliflozin and metformin)
- Farxiga (dapagliflozin)
- Xigduo XR (dapagliflozin and metformin)
- Jardiance (empagliflozin)
- Glyxambi (empagliflozin and linagliptin)
- Qtern (dapagliflozin and saxagliptin)
- Steglatro (ertugliflozin), Steglujan (ertugliflozin and sitagliptin)
However, the combination agents like Invokamet or Invokamet XR that contain metformin may be appropriate to start as a first-line agent in certain patients who need greater blood sugar control.
3. How Effective Is Invokana?
Invokana is typically used with other diabetes meds, like metformin, to lower blood sugar.
- In studies it lowered HbA1C (a measure of blood sugar control over the past two to three months) up to 0.7 percent, so it's a weak blood sugar lowering agent.
- However, Invokana is usually used as an "adjunct" (added to) to metformin, which boosts blood sugar control.
- There's a combined pill that makes it easier. Invokamet contains both metformin and canagliflozin in one tablet, which may be more convenient.
In October 2018 the FDA cleared Invokana to lower the risk of major adverse cardiovascular (CV) events, including heart attack, stroke or death in patients with type 2 diabetes who have established CV disease.
- For patients with type 2 diabetes and established heart disease, the American Diabetes Association (ADA) recommends medication management with SGLT2 inhibitors that specifically have a proven cardiovascular benefit, such as canagliflozin (Invokana) or empagliflozin (Jardiance). Pateints should have adequate kidney function for the choosen agent.
- Both agents have shown a reduction in heart failure and chronic kidney disease progression in cardiovascular outcomes trials.
- This new indication also applies to the fixed-dose combination products.
In September 2019, Janssen’s Invokana was approved to reduce the risk of end-stage kidney disease (ESKD), worsening of kidney function, cardiovascular (CV) death, and hospitalization for heart failure in adults with type 2 diabetes (T2D) and diabetic kidney disease.
Related: Invokana FDA approval history
4. Who Should Not Use Invokana?
Invokana was developed to treat type 2 diabetes in adults 18 years and older; it is not to be used to treat type 1 diabetes.
Invokana works in the kidneys, so you should not use Invokana if you have severe kidney problems or are on kidney dialysis. Your doctor will check your kidneys to see how well they work before you start Invokana or Invokamet, and periodically thereafter. If you notice signs of kidney injury, like decreased urine or swelling in the legs or feet, be sure to contact a healthcare provider immediately.
Tell your doctor if you have a history of prior amputation, peripheral vascular disease, neuropathy and diabetic foot ulcers. Invokana can increase the risk of amputations.
If you've had an allergic reaction in the past to canagliflozin - such as a rash, raised hives, or swelling - you should also not use Invokana. This includes swelling around your face, lips, mouth, tongue or throat that makes it difficult to breath or swallow.
Invokana should not be used to treat a condition called diabetic ketoacidosis, which is a potentially deadly complication of diabetes when you do not have enough insulin. In ketoacidosis, your blood becomes acidic (the pH is too low).
Tell your doctor if you are pregnant or plan to become pregnant. Invokana may harm your unborn baby. Tell your doctor right away if you become pregnant. Talk with your doctor about the best way to control your blood sugar while you are pregnant.
Do not breastfeed while taking Invokana. Talk to your doctor about the best way to feed your baby.
5. FDA: Other Warnings with Canagliflozin
Before you take Invokana or other medications containing canagliflozin, tell your doctor if you have a history of amputation, nerve damage in your leg (neuropathy), heart disease, narrow or blocked verssels, usually in your legs, or diabetic foot ulcers or sores.
- Canagliflozin may increase your risk of lower limb amputations. Invokana, Invokamet, and Invokamet XR contain a warning about the risk for amputations in the product labeling.
- The Boxed Warning for amputations, the most stringent type of safety warning from the FDA, was removed in August 2020 based on data from three clinical studies, but a risk still exists. The risk information is still found in the Warnings and Precautions section of the prescribing information.
Ketoacidosis (increased ketones in your blood or urine) has occurred in patients with type 1 diabetes or type 2 diabetes while taking Invokana. Invokana is not recommended for use in patients with type 1 diabetes. Major illness, reduced food and fluids, and reduced insulin doses can also cause ketoacidosis. Ketoacidosis is a serious condition, may require hospitalization, and can lead to death.
Signs or symptoms of ketoacidosis include:
- trouble breathing
- abdominal (stomach area) pain
- confusion, unusual fatigue or sleepiness.
If you have these symptoms, you should stop taking Invokana and call your doctor right away.
- Ketoacidosis can happen with Invokana even if your blood sugar is less than 250 mg/dL.
- Ask your health care provider about when and how to test for ketones. If you get these symptoms, if possible, check for ketones in your urine, even if your blood sugar is less than 250 mg/dL.
Also, the FDA warned that patients taking canaglifozin should notify their doctor right away if they notice any new pain, tenderness, sores, ulcers, or infections in their legs or feet. Plus, patients should talk to their doctor about factors that may increase their risk for bone fracture. Bone fractures have been seen in patients taking Invokana.
6. Invokana Side Effects: What Do You Need to Know?
The most common (5% or higher) Invokana side effects include:
- female yeast infections (of the vagina) and yeast infections in men (of the penis)
- urinary tract infections
- frequent urination
More serious side effects may include:
- lower limb amputations
- ketoacidosis (increased ketones in your blood or urine)
- high blood potassium levels (hyperkalemia)
- kidney injury
- low blood sugar (especially when used with other diabetes drugs like insulin, sulfonylureas, or meglinitides)
- serious allergies or angioedema
- dehydration and low blood pressure
- broken bones (fractures)
- increases in low-density lipoprotein (LDL-C), or "bad" cholesterol
- necrotizing fasciitis of the perineum (Fournier’s gangrene) - this causes damage to the tissue under the skin (necrotizing fasciitis) in the area between and around the anus and genitals (perineum)
Serious urinary tract infections (UTI) have occurred with this class of medications; contact your doctor if you have any symptoms of a UTI, such as:
- burning when urinating
- frequent need to urinate or need to urinate right away
- lower stomach (pelvis) pain
- blood in the urine
- back pain
- nausea or vomiting
7. Invokana: Drug and Dose Specifics
Your doctor will review how well your kidneys work before and during treatment with Invokana; you need good kidney function to take Invokana as that's where the drug works. You may need a dose reduction if you have kidney impairment, or for severe kidney disease, you may not be able to use Invokana at all.
Invokana is taken by mouth, and it comes in 100 milligram (mg) and 300 mg tablets. Usually, most patients will start at the 100 mg dose taken once a day before the first meal of the day.
If your blood sugar control is not adequate, your doctor may decide a higher Invokana dose is needed (but only if your kidney function is good enough for the higher dose).
Learn More: Review Invokana Dosing
8. What Other Medicines Do You Take?
Drug interactions should always be assessed whenever you start -- or even stop -- a medication. Like most other medicines, Invokana has important drug interactions you should be aware of.
Tell your doctor if you take diuretics (water pills to help with fluid) or digoxin (used to treat heart problems). Talk to your doctor about what you can do to prevent dehydration including how much fluid you should drink on a daily basis.
Drugs that are UGT enzyme inducers speed up removal of Invokana from the body and make it less effective. In patients who take UGT enzyme inducers (such as rifampin, phenytoin, phenobarbital, or ritonavir), you may need higher doses of Invokana to control your blood sugar. Talk to you doctor about this and ask your pharmacist for a drug interaction review.
Learn More: Search for Drug Interactions with Invokana
9. I Missed My Dose of Invokana. What Should I Do?
Low blood sugar (hypoglycemia) is not common with normal doses of Invokana. If you missed your dose of Invokana, take it as soon as you remember. But if it is almost time for next dose, skip the missed dose and take Invokana at your regularly scheduled time.
It is very important you do not take two doses of Invokana at the same time, unless your doctor instructs you to do this. Taking too much Invokana may dangerously lower your blood sugar.
Signs and symptoms of low blood sugar may include:
- fast heartbeat
- a shaky feeling.
Always keep a source of sugar like fruit juice, hard candy, or crackers with you in case you have low blood sugar.
10. Can I Afford To Buy Invokana?
Lower cost generics for Invokana may not be available until 2024. The retail cash price for this drug varies around the country, but in general may run from $500 to $600 per month.
Your insurance may cover all or some of the cost of this medication. Many Medicare Part D plans will also cover the cost of Invokana.
If you are not able to afford your medication, do not hesitate to speak to your doctor or pharmacist about this. It is a common problem. It may be that another more affordable medication can be prescribed.
If needed, Janssen, the manufacturer of Invokana, may be able to offer cost assistance for Invokana if you qualify. You can call them at 1-877-468-6526 (8 AM to 8 PM ET Monday - Friday) to speak with a Janssen CarePath Care Coordinator, or utiize their web-based patient savings programs found on the Janssen website.
Finished: Invokana Insights: 10 Drug Facts You Should Know
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- FDA removes Boxed Warning about risk of leg and foot amputations for the diabetes medicine canagliflozin (Invokana, Invokamet, Invokamet XR). FDA. Drug Safety Communication. Accessed April 10, 2021 at https://www.fda.gov/drugs/drug-safety-and-availability/fda-removes-boxed-warning-about-risk-leg-and-foot-amputations-diabetes-medicine-canagliflozin
- FDA Drug Safety Communication: FDA confirms increased risk of leg and foot amputations with the diabetes medicine canagliflozin (Invokana, Invokamet, Invokamet XR). US Food and Drug Administration (FDA). May 16, 2017. Accessed April 20, 2020 at https://www.fda.gov/Drugs/DrugSafety/ucm557507.htm
- Invokana Professional Information. Janssen. Revised: 8/2020. Accessed April 10, 2021 at https://www.janssenlabels.com/package-insert/product-monograph/prescribing-information/INVOKANA-pi.pdf
- FDA revises labels of SGLT2 inhibitors for diabetes to include warnings about too much acid in the blood and serious urinary tract infections. FDA Drug Safety Communication. Accessed April 11, 2020 at https://www.fda.gov/drugs/drug-safety-and-availability/fda-revises-labels-sglt2-inhibitors-diabetes-include-warnings-about-too-much-acid-blood-and-serious
- FDA Alert. New Drug Approved for Type 2 Diabetes. Drugs.com. April 1, 2013. Accessed April 20, 2020.
- Canagliflozin (Invokana, Invokamet) and Dapagliflozin (Farxiga, Xigduo XR): Drug Safety Communication - Strengthened Kidney Warnings. Drugs.com. June 14, 2016. Accessed April 20, 2020.
- Invokana and Invokamet (canagliflozin): Drug Safety Communication - New Information on Bone Fracture Risk and Decreased Bone Mineral Density. Drugs.com. Sept. 10, 2015. Accessed April 20, 2020.