Janumet is a combination of sitagliptin and metformin.

• Metformin is the oldest and time tested medicine and is the preferred initial treatment in most patients with type 2 diabetes mellitus.
• Sitagliptin is usually used if the patient is intolerant to metformin or is not achieving glycemic targets with other agents. Janumet is used as an adjunct to a healthy diet and aerobic exercise to improve glycemic control in adults with diabetes mellitus type 2 (when no contraindications to sitagliptin and metformin exist)

Janumet (Sitagliptin and metformin) dose in Adults

Janumet (Sitagliptin and metformin) dose in the treatment of Diabetes mellitus type 2:

• • Janumet or sitagliptin and metformin dosages are based on the patients' requirements. The usual initial dose is then titrated as per the glycemic response.
  • The total dose should be administered in 2 equally divided doses per day or as once daily (if the extended-release formulation is used).
  • The maximum doses, when used in combination, are 100 mg for sitagliptin and 2000 mg for metformin.

• Patients already taking metformin:

  • Sitagliptin 100 mg/day plus the current daily dose of metformin should be used.
  • Patients receiving metformin 850 mg twice daily may be switched to 1000 mg twice daily along with sitagliptin 50 mg twice daily or 100 mg once daily.

  • This is prescribed as:

    • Janumet 50/1000 mg twice daily or
    • Janumet 100/1000 mg once daily and metformin 1000 mg once daily.

• Patients not on metformin:

  • Sitagliptin 100 mg/metformin 1000 mg per day.

• Conversion from immediate-release to the extended-release formulation:

  • The same dosage should be used when converting from one formulation to the other.
  • However, the frequency should be adjusted.

• Dosage adjustment for concomitant therapy:

  • Patients receiving insulin or other concomitant medication like sulfonylureas may require lower initial dosages.

Use in Children:

Not recommended for use in children and type 1 diabetes mellitus.

Janumet (sitagliptin and metformin) Pregnancy Risk Category: B & C 

See individual agents - Metformin & Sitagliptin

• Metformin crosses over the placental boundary
• If the manufacturer suspects that the patient may have been inadvertently given the drug, the manufacturer suggests that they be registered.

Use of sitagliptin or metformin (Janumet), while breastfeeding

• Metformin can be excreted from breast milk. However, sitagliptin excretion is unknown.
• Manufacturers recommend that you weigh the benefits and risks of therapy.

Janumet (Sitagliptin and metformin) dose in kidney disease:

• eGFR >45 mL/minute/1.73 m2:

  • While dosage adjustment is not required, it is important to monitor renal function at least once a year.

• eGFR 30-45 mL/minute/1.73 2

  • Patients who are already on the drug can continue to take it. However, initiating treatment is not advised.
  • Sitagliptin should be administered at a dose of 50 mg daily if the eGFR drops below 45 mL/minute/1.73 m2. Metformin should also not exceed 1000 mg daily if this happens.
  • Patients with these conditions should be closely monitored (at minimum every 3 months).

• eGFR less than 30mL/minute/1.73m 2

  • It is best to avoid its use.

Janumet (Sitagliptin and metformin) dose in liver disease:

Metformin should not be used in patients with mild or moderate hepatic impairment. It should not be used in severe liver disease. Sitagliptin is not recommended for patients suffering from liver disease.

See individual agents for side effects of each drug - Metformin and sitagliptin.

Side Effects of Janumet (Sitagliptin and metformin):

• Central nervous system:

  • Headache

• Gastrointestinal:

  • Diarrhea
  • Nausea
  • Abdominal pain
  • Vomiting

• Respiratory:

  • Upper respiratory tract infection

Contraindications to Janumet (Sitagliptin and metformin):

• Allergy reactions to sitagliptin or metformin or any component of this formulation
• Severe renal impairment (eGFR of less than 30mL/minute/1.73m2
• Metabolic acidosis, including diabetic ketoacidosis.
• Type 2 diabetes mellitus and unstable diabetes type 2
• Ketoacidosis: History
• History of lactic acidosis regardless of precipitating factors
• Alcoholism is a problem.
• Advanced liver disease
• Hypoxemia, especially from cardiovascular collapse or cardiorespiratory impairment, is a sign of hypoxemia.
• Use in stressful situations such as surgery, severe infection, or trauma
• Shock or severe dehydration
• Pregnancy
• Breastfeeding
• During the administration of iodinatedcontrasting materials.

Warnings and precautions

• Arthralgia

  • DPP-IV patients may experience severe and disabling arthritis. This may occur from as little as one to several years after the initial diagnosis.
  • It is important to withhold treatment that does not resolve the symptoms. However, recurrences may occur if treatment continues.

• Bullous pemphigoid

  • Bullous pemphigoid was associated with DPP-IV inhibitors
  • Bullous pemphigoid may be treated with systemic or topical immunosuppressive therapy, and possibly discontinue DPP-4 inhibitor therapy.
  • If blisters occur, patients should inform their doctor immediately.
  • If the patient suspects that there is a problem, he or she should be referred immediately to a dermatologist.

• Hypersensitivity reactions

  • Reports of severe allergic reactions such as anaphylaxis, angioedema, and severe skin reactions like Stevens-Johnson syndrome were made.
  • Most allergic reactions occur within the first three month of therapy, especially if the initial dose was taken or if there has been angioedema.
  • If symptoms of allergic reaction are present, the treatment should be stopped immediately.

• Lactic acidosis: [US Boxed Warning]

  • Metformin-induced lactic acidosis can be life-threatening. It can cause death, hypothermia and hypotension, as well as cardiac bradyarrhythmias.
  • Non-specific symptoms of lactic acidosis include malaise, myalgias and somnolence.
  • It is characterised by high blood lactate levels (more that 5 mmol/L), anion gaps metabolic acidosis and increased lactate:pyruvate ratio. Plasma metformin levels are more than 5 mg/ml.
  • These patients are at high risk for developing lactic acidosis:
    • Patients with severe renal impairment
    • Use of other drugs, such as topiramate or Acetazolamide, in conjunction with certain drugs
    • Over 65
    • Radiocontrast study of patients
    • Major surgeries and diagnostic procedures are performed on patients undergoing major surgery.
    • Hypoxic states, such as heart failure, can be hypoxic.
    • Hepatic impairment
    • Alcohol intake that is excessive
  • Patients with lactic acidosis must stop treatment immediately. They may need hemodialysis.

• Pancreatitis

  • DPP IV inhibitors have been shown to be effective in treating acute pancreatitis, including necrotizing and hemorhagic pancreatitis. These cases can prove fatal.
  • Patients who have had a history of pancreatitis in the past should not take this drug.

• Effects on the renal system:

  • Acute renal failure can occur in patients and they may need hemodialysis.

• Concentrations of Vitamin B:

  • Metformin long-term use is linked to vitamin B-12 deficiency.
  • Patients with anemia or peripheral neuropathy should have their serum levels of vitamin A 12 levels monitored regularly.

• Bariatric surgery

  • Absorption altered:

    • Bariatric surgery (gastric bypass, sleeve-gastrectomy) alters the anatomy of your intestine, so it is possible that absorption of food and drugs will be affected.
    • These patients should prefer to use the immediate-release formulation.
    • The extended-release tablets are less effective due to direct bypass of stomach with gastric bypass surgery, rapid gastric emptying, and small bowel transit using sleeve gastricectomy.
    • After gastric bypass surgery (Rouxen-Y gastric bypass [RYGB]), the absorption of immediate-release tablets increases by 50%.
    • The gastric bypass (RYGB), which results in weight loss, causes a decrease in the level of lactate. This is independent of whether metformin was used.
    • Metformin doses should not be reduced after gastric bypass, as long as renal function is maintained.

  • Exposure to Glucagon-like peptide-1 and its therapeutic efficacy

    • It is important to monitor patients for signs and symptoms of pancreatitis.
    • The possibility of gastric bypass surgery or sleeve-gastrectomy causing an increase in endogenous secretion 1 of glucagon like peptide-1 may be present.

• Cardiovascular disease

  • Patients suffering from unstable heart failure may be at high risk for lactic acidosis secondary hypoperfusion.
  • It can be used for patients with stable heart disease and associated with reduced hospital admissions and mortality.
  • Heart failure has been linked to DPP IV inhibitors. It can exacerbate myocardial damage.
  • The TECOS trial found that sitagliptin did not increase the risk of angina, non-fatal myocardial injury or hospitalization due to cardiovascular disease.
  • According to the American Diabetes Association, DPP-4 inhibitors (saxagliptin excluded) might be considered for patients with heart disease.

• Hepatic impairment

  • Metformin may be recommended for patients with mild to moderate liver dysfunction. However, individuals with advanced liver disease or unstable liver function may need to be careful.
  • Patients with advanced liver disease should avoid it.
  • Metformin has a survival benefit in carefully selected patients.

• Renal impairment

  • Metformin is excreted through the kidneys.
  • Before initiating treatment, patients should have their renal function checked and again periodically thereafter.
  • Patients with a lower eGFR than 30 ml/min/1.73m2 should not use it.
  • Patients with an eGFR of 30 to 45 ml/min or less should have their dose reduced.
  • Patients suffering from acute renal dysfunction or dehydration should not use it.
  • Patients with impaired renal function should have their sitagliptin doses reduced.
  • Metformin disposition may be affected by medications that can affect kidney function.

• Stress-related disorders:

  • Patients suffering from acute stress such as trauma, fever, infection, or surgery should not use insulin. Instead, they should be prescribed insulin.

Monitor:

• HbA 1c

  • Patints with stable glycemic control -- Twice annually

  • Patients with uncontrolled blood glucose, or patients who are receiving a change of treatment - every 3 months.

• Plasma glucose

• Annual Blood CP (CBC).

• Annual liver function tests

• Renal function (and the eGFR).

• These tests should be done before starting therapy, and every year thereafter. 

• Patients who are at high risk for developing renal impairment should have their renal function tested more often.

  • People with a GFR between 45 and 60 mg/min/1.73m2 - Every 3 - 6 months

  • For those with a GFR of 45ml/min/1.73m2 - Every 3 months

• Vitamin B 12 levels every two to three years

• If megaloblastic anemia is suspected, ensure that you have sufficient Folate.

• Monitor the patient for signs of heart failure and pancreatitis.

How to administer Janumet (Sitagliptin and metformin)?

• Orally administer the drug with meals (preferably with an evening meal for extended-release tablet).
• The extended-release tablets should be swallowed whole. 
• Do not chew, crush, or split the extended-release tablets. Avoid dividing immediate-release tablets.

Mechanism of action of Sitagliptin and metformin:

• Sitagliptin (DPP-IV enzyme inhibitor) is a dipeptidyl Peptide IV (DPP IV) enzyme inhibitor. DPP-IV is an enzyme which inactivates incretin. DPP-IV inhibition results in increased active incretin levels. GLP-1 and GIP-1, which are both insulin hormones that include glucose-dependent insulinotropic peptide (GIP), increase insulin synthesis from pancreatic beta cells. They also decrease glucagon secretion in the pancreatic alpha cell. A low hepatic glucose production is due to decreased synthesis and secretion glucagon. INCRETIN stands for acronym INTestinal seCRETIon of INSulin. Normal healthy people release incretin hormones throughout the day. However, their levels rise after eating.
• Metformin, a well-researched anti-hyperglycemic medicine, reduces insulin sensitivity and intestinal glucose absorption.

For more information, please contact individual agents - Sitagliptin & Metformin.

International Brand Names of Sitagliptin and metformin:

• Janumet
• Janumet XR
• Efficib
• Glaptivia Plus
• Janmet
• Januet
• Januet XR
• Janugliptin Plus
• Janumet
• Janumet XR
• Ristfor
• Sitomet
• Velmetia

Sitagliptin Metformin Brand Names in Pakistan:

  Sitaphage (Martin Dow) 50/500 and 50/1000 mg Tablets