Janumet Side Effects Center

Last updated on RxList: 7/1/2022
Janumet Side Effects Center

What Is Janumet?

Janumet (sitagliptin/metformin HCl) is a combination of oral diabetes medicines for people with type 2 diabetes who do not use daily insulin injections. Janumet is not for treating type 1 diabetes.

What Are Side Effects of Janumet?

Common side effects of Janumet include:

Janumet does not usually cause low blood sugar (hypoglycemia). Low blood sugar may occur if Janumet is prescribed with other anti-diabetic medications. Symptoms of low blood sugar include sudden sweating, shaking, fast heartbeat, hunger, blurred vision, dizziness, or tingling hands/feet.

Seek medical care or call 911 at once if you have the following serious side effects:

  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheartedness, or passing out;
  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

Dosage for Janumet

Dosage of Janumet is individualized. Janumet is given twice daily with meals in 50 mg sitagliptin/500 mg metformin hydrochloride or 50 mg sitagliptin/1000 mg metformin hydrochloride doses.

What Drugs, Substances, or Supplements Interact with Janumet?

Hyperglycemia (high blood sugar) may result if you take Janumet with drugs that raise blood sugar, such as: isoniazid, diuretics (water pills), steroids, phenothiazines, thyroid medicine, birth control pills and other hormones, seizure medicines, and diet pills, or medicines to treat asthma, colds or allergies. Hypoglycemia (low blood sugar) may result if you take Janumet with drugs that lower blood sugar, such as: nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin or other salicylates, sulfa drugs, monoamine oxidase inhibitors (MAOIs), beta-blockers, or probenecid. It may also interact with amiloride, triamterene, cimetidine, ranitidine, digoxin, furosemide, morphine, nifedipine, procainamide, quinidine, trimethoprim, or vancomycin. Tell your doctor all medications you use.

Janumet During Pregnancy or Breastfeeding

During pregnancy, Janumet should be used only when prescribed. Your doctor may direct you to use insulin instead of this product during your pregnancy. Metformin can promote ovulation and increase the risk of becoming pregnant. Consult your doctor about use of birth control. Metformin passes into breast milk in small amounts. It is unknown if sitagliptin passes into breast milk. Consult your doctor before breastfeeding.

Additional Information

Our Janumet (sitagliptin/metformin HCl) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

QUESTION

______________ is another term for type 2 diabetes. See Answer
Janumet Consumer Information

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).

Stop taking this medicine and call your doctor right away if you have symptoms of pancreatitis: severe pain in your upper stomach spreading to your back, nausea and vomiting, loss of appetite, or fast heartbeats.

Some people using metformin develop lactic acidosis, which can be fatal. Get emergency medical help if you have even mild symptoms such as:

  • unusual muscle pain;
  • feeling cold;
  • trouble breathing;
  • feeling dizzy, light-headed, tired, or very weak;
  • stomach pain, vomiting; or
  • irregular heart rate.

Call your doctor at once if you have any of these serious side effects:

  • severe autoimmune reaction--itching, blisters, breakdown of the outer layer of skin;
  • severe or ongoing pain in your joints;
  • little or no urinating; or
  • symptoms of heart failure--shortness of breath (even while lying down), swelling in your legs or feet, rapid weight gain.

Common side effects may include:

  • low blood sugar (if you also use insulin or another oral diabetes medication);
  • upset stomach, indigestion, gas, diarrhea, nausea, vomiting;
  • headache, weakness; or
  • cold symptoms such as runny or stuffy nose, sneezing, sore throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

SLIDESHOW

Type 2 Diabetes: Signs, Symptoms, Treatments See Slideshow
Janumet Professional Information

SIDE EFFECTS

The following adverse reactions are also discussed elsewhere in the labeling:

  • Lactic Acidosis [see WARNINGS AND PRECAUTIONS]
  • Pancreatitis [see WARNINGS AND PRECAUTIONS]
  • Heart Failure [see WARNINGS AND PRECAUTIONS]
  • Acute Renal Failure [see WARNINGS AND PRECAUTIONS]
  • Vitamin B12 Deficiency [see WARNINGS AND PRECAUTIONS]
  • Hypoglycemia with Concomitant Use with Insulin or Insulin Secretagogues [see WARNINGS AND PRECAUTIONS]
  • Hypersensitivity Reactions [see WARNINGS AND PRECAUTIONS]
  • Severe and Disabling Arthralgia [see WARNINGS AND PRECAUTIONS]
  • Bullous Pemphigoid [see WARNINGS AND PRECAUTIONS]

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Sitagliptin And Metformin Coadministration In Patients With Type 2 Diabetes Inadequately Controlled On Diet And Exercise

Table 1 summarizes the most common (≥5% of patients) adverse reactions reported (regardless of investigator assessment of causality) in a 24-week placebo-controlled factorial study in which sitagliptin and metformin were coadministered to patients with type 2 diabetes inadequately controlled on diet and exercise.

Table 1: Sitagliptin and Metformin Coadministered to Patients with Type 2 Diabetes Inadequately Controlled on Diet and Exercise: Adverse Reactions Reported (Regardless of Investigator Assessment of Causality) in 5% of Patients Receiving Combination Therapy (and Greater than in Patients Receiving Placebo)*

Number of Patients (%)
Placebo Sitagliptin 100 mg once daily Metformin HCl 500 mg/ Metformin HCl 1000 mg twice daily Sitagliptin 50 mg twice daily + Metformin HCl 500 mg/ Metformin HCl 1000 mg twice daily
N = 176 N = 178 N = 364 N = 372
Diarrhea 7 (4.0) 5 (2.8) 28 (7.7) 28 (7.5)
Upper Respiratory Tract Infection 9 (5.1) 8 (4.5) 19 (5.2) 23 (6.2)
Headache 5 (2.8) (1.1) 14 (3.8) 22 (5.9)
* Intent-to-treat population.
Data pooled for the patients given the lower and higher doses of metformin.

Sitagliptin Add-On Therapy In Patients With Type 2 Diabetes Inadequately Controlled On Metformin Alone

In a 24-week placebo-controlled trial of sitagliptin 100 mg administered once daily added to a twice daily metformin regimen, there were no adverse reactions reported regardless of investigator assessment of causality in ≥5% of patients and more commonly than in patients given placebo. Discontinuation of therapy due to clinical adverse reactions was similar to the placebo treatment group (sitagliptin and metformin, 1.9%; placebo and metformin, 2.5%).

Gastrointestinal Adverse Reactions

The incidences of pre-selected gastrointestinal adverse experiences in patients treated with sitagliptin and metformin were similar to those reported for patients treated with metformin alone. See Table 2.

Table 2: Pre-selected Gastrointestinal Adverse Reactions (Regardless of Investigator Assessment of Causality) Reported in Patients with Type 2 Diabetes Receiving Sitagliptin and Metformin

Number of Patients (%)
Study of Sitagliptin and Metformin in Patients Inadequately Controlled on Diet and Exercise Study of Sitagliptin Add-on in Patients Inadequately Controlled on Metformin Alone
Placebo Sitagliptin 100 mg once daily Metformin HCl 500 mg/ Metformin HCl 1000 mg twice daily* Sitagliptin 50 mg twice daily + Metformin HCl 500 mg/ Metformin HCl 1000 mg twice daily* Placebo and Metformin HCl ≥1500 mg daily Sitagliptin 100 mg once daily and Metformin HCl ≥1500 mg daily
N = 176 N = 179 N = 364 N = 372 N = 237 N = 464
Diarrhea 7 (4.0) 5 (2.8) 28 (7.7) 28 (7.5) 6 (2.5) 11 (2.4)
Nausea 2 (1.1) 2 (1.1) 20 (5.5) 18 (4.8) 2 (0.8) 6 (1.3)
Vomiting 1 (0.6) 0 (0.0) 2 (0.5) 8 (2.2) 2 (0.8) 5 (1.1)
Abdominal Pain 4 (2.3) 6 (3.4) 14 (3.8) 11 (3.0) 9 (3.8) 10 (2.2)
* Data pooled for the patients given the lower and higher doses of metformin.
Abdominal discomfort was included in the analysis of abdominal pain in the study of initial therapy.

Sitagliptin In Combination With Metformin And Glimepiride

In a 24-week placebo-controlled study of sitagliptin 100 mg as add-on therapy in patients with type 2 diabetes inadequately controlled on metformin and glimepiride (sitagliptin, N=116; placebo, N=113), the adverse reactions reported regardless of investigator assessment of causality in ≥5% of patients treated with sitagliptin and more commonly than in patients treated with placebo were: hypoglycemia (Table 3) and headache (6.9%, 2.7%).

Sitagliptin In Combination With Metformin And Rosiglitazone

In a placebo-controlled study of sitagliptin 100 mg as add-on therapy in patients with type 2 diabetes inadequately controlled on metformin and rosiglitazone (sitagliptin, N=181; placebo, N=97), the adverse reactions reported regardless of investigator assessment of causality through Week 18 in ≥5% of patients treated with sitagliptin and more commonly than in patients treated with placebo were: upper respiratory tract infection (sitagliptin, 5.5%; placebo, 5.2%) and nasopharyngitis (6.1%, 4.1%). Through Week 54, the adverse reactions reported regardless of investigator assessment of causality in ≥5% of patients treated with sitagliptin and more commonly than in patients treated with placebo were: upper respiratory tract infection (sitagliptin, 15.5%; placebo, 6.2%), nasopharyngitis (11.0%, 9.3%), peripheral edema (8.3%, 5.2%), and headache (5.5%, 4.1%).

Sitagliptin In Combination With Metformin And Insulin

In a 24-week placebo-controlled study of sitagliptin 100 mg as add-on therapy in patients with type 2 diabetes inadequately controlled on metformin and insulin (sitagliptin, N=229; placebo, N=233), the only adverse reaction reported regardless of investigator assessment of causality in ≥5% of patients treated with sitagliptin and more commonly than in patients treated with placebo was hypoglycemia (Table 3).

Hypoglycemia

In the above studies (N=5), adverse reactions of hypoglycemia were based on all reports of symptomatic hypoglycemia; a concurrent glucose measurement was not required although most (77%) reports of hypoglycemia were accompanied by a blood glucose measurement ≤70 mg/dL. When the combination of sitagliptin and metformin was coadministered with a sulfonylurea or with insulin, the percentage of patients reporting at least one adverse reaction of hypoglycemia was higher than that observed with placebo and metformin coadministered with a sulfonylurea or with insulin (Table 3).

Table 3: Incidence and Rate of Hypoglycemia* (Regardless of Investigator Assessment of Causality) in Placebo-Controlled Clinical Studies of Sitagliptin in Combination with Metformin Coadministered with Glimepiride or Insulin

Add-On to Glimepiride + Metformin (24 weeks) Sitagliptin 100 mg + Metformin + Glimepiride Placebo + Metformin + Glimepiride
N = 116 N = 113
  Overall (%) 19 (16.4) 1 (0.9)
  Rate (episodes/patient-year) 0.82 0.02
  Severe (%) 0 (0.0) 0 (0.0)
Add-On to Insulin + Metformin (24 weeks) Sitagliptin 100 mg + Metformin + Insulin Placebo + Metformin + Insulin
N = 229 N = 233
  Overall (%) 35 (15.3) 19 (8.2)
  Rate (episodes/patient-year) 0.98 0.61
  Severe (%) 1 (0.4) 1 (0.4)
* Adverse reactions of hypoglycemia were based on all reports of symptomatic hypoglycemia; a concurrent glucose measurement was not required: Intent-to-treat population.
Based on total number of events (i.e., a single patient may have had multiple events).
Severe events of hypoglycemia were defined as those events requiring medical assistance or exhibiting depressed level/loss of consciousness or seizure.

The overall incidence of reported adverse reactions of hypoglycemia in patients with type 2 diabetes inadequately controlled on diet and exercise was 0.6% in patients given placebo, 0.6% in patients given sitagliptin alone, 0.8% in patients given metformin alone, and 1.6% in patients given sitagliptin in combination with metformin. In patients with type 2 diabetes inadequately controlled on metformin alone, the overall incidence of adverse reactions of hypoglycemia was 1.3% in patients given add-on sitagliptin and 2.1% in patients given add-on placebo.

In the study of sitagliptin and add-on combination therapy with metformin and rosiglitazone, the overall incidence of hypoglycemia was 2.2% in patients given add-on sitagliptin and 0.0% in patients given add-on placebo through Week 18. Through Week 54, the overall incidence of hypoglycemia was 3.9% in patients given add-on sitagliptin and 1.0% in patients given add-on placebo.

In an additional, 30-week placebo-controlled, study of patients with type 2 diabetes inadequately controlled with metformin comparing the maintenance of sitagliptin 100 mg versus withdrawal of sitagliptin when initiating basal insulin therapy, the event rate and incidence of documented symptomatic hypoglycemia (blood glucose measurement ≤70 mg/dL) did not differ between the sitagliptin and placebo groups.

Vital Signs And Electrocardiograms

With the combination of sitagliptin and metformin, no clinically meaningful changes in vital signs or in ECG (including in QTc interval) were observed.

Pancreatitis

In a pooled analysis of 19 double-blind clinical trials that included data from 10,246 patients randomized to receive sitagliptin 100 mg/day (N=5429) or corresponding (active or placebo) control (N=4817), the incidence of acute pancreatitis was 0.1 per 100 patient-years in each group (4 patients with an event in 4708 patient-years for sitagliptin and 4 patients with an event in 3942 patient-years for control).

Sitagliptin

The most common adverse experience in sitagliptin monotherapy reported regardless of investigator assessment of causality in ≥5% of patients and more commonly than in patients given placebo was nasopharyngitis.

Metformin

The most common (>5%) established adverse reactions due to initiation of metformin therapy are diarrhea, nausea/vomiting, flatulence, abdominal discomfort, indigestion, asthenia, and headache.

Laboratory Tests
Sitagliptin

The incidence of laboratory adverse reactions was similar in patients treated with sitagliptin and metformin (7.6%) compared to patients treated with placebo and metformin (8.7%). In most but not all studies, a small increase in white blood cell count (approximately 200 cells/microL difference in WBC vs placebo; mean baseline WBC approximately 6600 cells/microL) was observed due to a small increase in neutrophils. This change in laboratory parameters is not considered to be clinically relevant.

Metformin

In controlled clinical trials of metformin of 29 weeks duration, a decrease to subnormal levels of previously normal serum vitamin B12 levels, without clinical manifestations, was observed in approximately 7% of patients. Such decrease, possibly due to interference with B12 absorption from the B12-intrinsic factor complex, is, however, very rarely associated with anemia and appears to be rapidly reversible with discontinuation of metformin or vitamin B12 supplementation.

Postmarketing Experience

Additional adverse reactions have been identified during postapproval use of JANUMET, sitagliptin, or metformin. Because these reactions are reported voluntarily from a population of uncertain size, it is generally not possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Hypersensitivity reactions including anaphylaxis, angioedema, rash, urticaria, cutaneous vasculitis, and exfoliative skin conditions including Stevens-Johnson syndrome; upper respiratory tract infection; hepatic enzyme elevations; acute pancreatitis, including fatal and non-fatal hemorrhagic and necrotizing pancreatitis [see INDICATIONS]; worsening renal function, including acute renal failure (sometimes requiring dialysis) and tubulointerstitial nephritis; severe and disabling arthralgia; bullous pemphigoid; constipation; vomiting; headache; myalgia; pain in extremity; back pain; pruritus; mouth ulceration; stomatitis; cholestatic, hepatocellular, and mixed hepatocellular liver injury; rhabdomyolysis.

DRUG INTERACTIONS

Table 4 presents clinically significant drug interactions with JANUMET:

Table 4: Clinically Significant Drug Interactions with JANUMET

Carbonic Anhydrase Inhibitors
Clinical Impact: Carbonic anhydrase inhibitors frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of these drugs with JANUMET may increase the risk for lactic acidosis.
Intervention: Consider more frequent monitoring of these patients.
Examples: Topiramate, zonisamide, acetazolamide or dichlorphenamide.
Drugs that Reduce Metformin Clearance
Clinical Impact: Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2] / multidrug and toxin extrusion [MATE] inhibitors) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see CLINICAL PHARMACOLOGY ].
Intervention: Consider the benefits and risks of concomitant use with JANUMET.
Examples: Ranolazine, vandetanib, dolutegravir, and cimetidine.
Alcohol
Clinical Impact: Alcohol is known to potentiate the effect of metformin on lactate metabolism.
Intervention: Warn patients against alcohol intake while receiving JANUMET.
Insulin Secretagogues or Insulin
Clinical Impact: Coadministration of JANUMET with an insulin secretagogue (e.g., sulfonylurea) or insulin may increase the risk of hypoglycemia.
Intervention: Patients receiving an insulin secretagogue or insulin may require lower doses of the insulin secretagogue or insulin.
Drugs Affecting Glycemic Control
Clinical Impact: Certain drugs tend to produce hyperglycemia and may lead to loss of glycemic control.
Intervention: When such drugs are administered to a patient receiving JANUMET, observe the patient closely for loss of blood glucose control. When such drugs are withdrawn from a patient receiving JANUMET, observe the patient closely for hypoglycemia.
Examples: Thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers, and isoniazid.

Read the entire FDA prescribing information for Janumet (Sitagliptin Metformin HCL)

© Janumet Patient Information is supplied by Cerner Multum, Inc. and Janumet Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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