Pharmacy Diabetes

Saxagliptin/metformin XR

Name of Medicine
  • Saxagliptin (as hydrochloride)/ metformin hydrochloride
Presentation
  • SAXAGLIPTIN/METFORMIN XR 5/500 tablets containing 5 mg saxagliptin immediate release and 500 mg metformin modified release.
  • SAXAGLIPTIN/METFORMIN XR 5/1000 tablets containing 5 mg saxagliptin immediate release and 1000 mg metformin modified release.

SAXAGLIPTIN/METFORMIN XR 2.5/1000 tablets containing 2.5 mg saxagliptin  immediate release and 1000 mg metformin  modified release

Key Practice Points
Therapeutic Indications:

SAXAGLIPTIN/METFORMIN XR is indicated as an adjunct to healthy eating and physical activity to improve glycaemic management in adults with type 2 diabetes mellitus when treatment with both saxagliptin and metformin is appropriate.

 

For the latest PBS indications for SAXAGLIPTIN/METFORMIN XR please see

https://www.pbs.gov.au/pbs/search?analyse=false&term=Saxagliptin/metformin%20xr%205%2F1000&search-type=medicines

Dose:
  • SAXAGLIPTIN/METFORMIN XR should be taken with or after food
  • The dosage of diabetes therapy with SAXAGLIPTIN/METFORMIN XR should be individualised based on the person’s current regimen, effectiveness, and tolerability while not exceeding the maximum recommended dose of saxagliptin 5 mg and metformin extended release 2000 mg.
  • SAXAGLIPTIN/METFORMIN XR should generally be administered once daily with the evening meal, with gradual dose titration to reduce the gastrointestinal side effects associated with metformin.
  • Individuals should be informed that SAXAGLIPTIN/METFORMIN XR tablets must be swallowed whole and never crushed, cut, or chewed. Occasionally, the inactive ingredients of SAXAGLIPTIN/METFORMIN XR will be eliminated in the faeces as a soft, hydrated mass that may resemble the original tablet.
  • As add on combination therapy: If therapy with a combination tablet containing saxagliptin and metformin is considered appropriate, the recommended dose of saxagliptin is 5 mg once daily. The recommended starting dose of metformin extended release is 500 mg once daily, which can be titrated to 2000 mg once daily. The maximum dose of SAXAGLIPTIN/METFORMIN XR is saxagliptin 5 mg/metformin extended release 2000 mg taken as two 2.5 mg/1000 mg tablets once daily.
  • As initial combination therapy: The recommended starting doses of SAXAGLIPTIN/METFORMIN XR when used as initial combination therapy is one 5 mg/500 mg tablet once daily. Individuals with inadequate glycaemic management on this starting dose should further have their metformin dose increased to 5 mg/1000 mg once daily or two 2.5 mg/1000 mg tablets once daily as appropriate.
  • Renal impairment: Renal function should be assessed prior to initiation of SAXAGLIPTIN/METFORMIN XR and periodically thereafter. Factors that may increase the risk of lactic acidosis should be reviewed before considering initiation of SAXAGLIPTIN/METFORMIN XR in those with eGFR < 60 mL/min/1.73m2.

– Mild renal impairment (eGFR 60-89 mL/min/1.73m2): No dosage adjustment is required for those with mild renal impairment. (eGFR 60-89 mL/min/1.73 m2.

– Moderate renal impairment (eGFR 30-59 mL/min/1.73 m2): No dosage adjustment is required for individuals with eGFR ≥ 45 mL/min/1.73 m2

– It is not recommended to initiate treatment with SAXAGLIPTIN/METFORMIN XR in those with eGFR <45 mL/min/1.73 m2. If during treatment eGFR falls to levels persistently below 45 mL/min/1.73 m2, assess the benefit and risk of continuing therapy and limit the maximum dose of SAXAGLIPTIN/METFORMIN XR to 2.5 mg/1000 mg once daily.

– Severe Renal Impairment (eGFR < 30 mL/min/1.73 m2): SAXAGLIPTIN/METFORMIN XR is contraindicated in individuals with severe renal impairment (eGFR < 30mL/min/1.73 m2).

 

  • Hepatic impairment: Since impaired hepatic function has been associated with some cases of lactic acidosis in those taking metformin, SAXAGLIPTIN/METFORMIN XR should be avoided with clinical or laboratory evidence of hepatic impairment.
Elderly:
  • Saxagliptin and metformin are eliminated in part by the kidney, and therefore, because the elderly are more likely to have decreased renal function, SAXAGLIPTIN/METFORMINXR should be used with caution as age increases.
Contraindications:
  • Hypersensitivity to the active substances or to any of the excipients, or a history of any serious hypersensitivity reaction, including anaphylactic reaction and angioedema, to any dipeptidyl peptidase 4 (DPP4) inhibitor.
  • Metabolic acidosis: Acute or chronic metabolic acidosis, including lactic acidosis or ketoacidosis, with or without coma. Ketoacidosis should be treated with insulin.
  • Pre-coma
  • Severe renal impairment (eGFR < 30 mL/min/1.73 m2)
  • Acute conditions with the potential to alter renal function such as: dehydration, severe infection, shock, or intravascular administration of iodinated contrast agents.
  • Acute or chronic disease which may cause tissue hypoxia such as: cardiac or respiratory failure, pulmonary embolism, recent myocardial infarction, shock, acute significant blood loss, sepsis, gangrene, pancreatitis; during or immediately following surgery where insulin is essential, elective major surgery.
  • Hepatic impairment
  • Acute alcohol intoxication, alcoholism.
  • Lactation
Precautions:
  • General: SAXAGLIPTIN/METFORMIN XR should not be used in individuals with type 1 diabetes mellitus. SAXAGLIPTIN/METFORMIN XR has not been studied in combination with GLP-agonists.
  • Metformin

– Lactic acidosis: Lactic acidosis is a rare, but serious metabolic complication that can occur due to metformin accumulation during treatment with metformin. When it occurs, it is fatal in approximately 50% of cases. Lactic acidosis is a medical emergency and must be treated in hospital immediately. The risk of lactic acidosis increases with the degree of renal dysfunction. Reported cases of lactic acidosis in individuals on metformin have occurred primarily in those with diabetes with significant renal insufficiency, often in the setting of multiple concomitant medical/surgical problems and multiple concomitant medications. Special caution should be taken in the elderly due to the decrease of renal function with age.

Note: Diabetes MedsCheck with referral to healthcare team for education on lactic acidosis.

-Surgery: Metformin must be discontinued at the time of surgery under general, spinal, or epidural anaesthesia. Therapy may be restarted no earlier than 48 hours following surgery or resumption of oral nutrition and provided that renal function has been re-evaluated and found to be stable.

-Alcohol Intake: Alcohol is known to potentiate the effect of metformin on lactate metabolism. Individuals, therefore, should be warned against excessive alcohol intake while receiving SAXAGLIPTIN/METFORMIN XR.

  • Monitoring of renal function: Renal function should be confirmed before initiation of SAXAGLIPTIN/METFORMIN XR therapy, and then at least once a year in those with normal renal function and at least two to four times a year if serum creatinine levels are at or above the upper limit of normal and in elderly individuals. Decreased renal function in the elderly is frequent and asymptomatic. Special caution should be exercised in situations where renal function may become impaired, for example when initiating antihypertensive or diuretic therapy or when starting treatment with a nonsteroidal anti-inflammatory drug (NSAID).

Note: Diabetes MedsCheck with referral for annual cycle of care.

Adverse Effects:
  • Metformin

– Gastrointestinal disorders: Gastrointestinal symptoms such as nausea, vomiting, diarrhoea, abdominal pain, and loss of appetite are very common (>10%): these occur most frequently during initiation of therapy and resolve spontaneously in most cases. To prevent these gastrointestinal symptoms, it is recommended that this medicinal product be taken in 2 or 3 daily doses. A slow increase of the dose may also improve gastrointestinal tolerability.

– Metabolism and nutrition disorders: Lactic acidosis is a very rare (<0.01%) but serious metabolic complication that can occur due to metformin accumulation during treatment with metformin. The onset of lactic acidosis is often subtle and accompanied only by non-specific symptoms such as malaise, myalgia, respiratory distress, increasing somnolence and non-specific abdominal distress. There may be associated hypothermia, hypotension and resistant bradyarrhythmia’s with more marked acidosis.

Note: Diabetes MedsCheck with referral to healthcare team for education on lactic acidosis.

– Hepatobiliary disorders: Very rare: liver function test abnormalities or hepatitis requiring treatment discontinuation.

– Skin and subcutaneous tissue disorders: Skin reactions such as erythema, pruritus and urticaria have been reported but the incidence is very rare (<0.01%).

– Nervous system disorders

– Taste disturbance (3 %) is common.

– Vitamin B12 Levels: In controlled, 29-week clinical trials of immediate release metformin, 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 anaemia and appears to be rapidly reversible with discontinuation of metformin or Vitamin B12 supplementation. Measurement of haematologic parameters on an annual basis is advised in those on SAXAGLIPTIN/METFORMIN XR and any apparent abnormalities should be appropriately investigated and managed. Certain individuals (those with inadequate Vitamin B12 or calcium intake or absorption) appear to be predisposed to developing subnormal Vitamin B12 levels). See interventions for further information.

  • Saxagliptin

– During post marketing experience the following adverse reactions have been reported with use of saxagliptin: serious hypersensitivity reactions, including anaphylaxis and angioedema. Because these reactions are reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency. If a serious hypersensitivity reaction to saxagliptin is suspected, discontinue SAXAGLIPTIN/METFORMIN XR, assess for other potential causes for the event, and institute alternative treatment for diabetes.

 

 

– Pancreatitis: During post marketing experience, there have been spontaneously reported adverse reactions of acute pancreatitis. Individuals should be informed of the characteristic symptom of acute pancreatitis: persistent, severe abdominal pain. If pancreatitis is suspected, SAXAGLIPTIN/METFORMIN XR should be discontinued.

Note: Diabetes MedsCheck with counselling on side effect profile and referral to healthcare team if suspected.

-Bullous pemphigoid: post-marketing cases of bullous pemphigoid requiring hospitalisation have been reported with DPP4 inhibitor use. In reported cases, individuals typically recovered with topical or systemic immunosuppressive treatment and discontinuation of the DPP-4 inhibitor. Tell individuals to report development of blisters or erosions while receiving SAXAGLIPTIN/METFORMIN XR. If bullous pemphigoid is suspected, SAXAGLIPTIN/METFORMIN XR should be discontinued and referral to a dermatologist should be considered for diagnosis and appropriate treatment.

Note: Diabetes MedsCheck with counselling on side effect profile and referral to healthcare team if suspected.

-Arthralgia: There have been post marketing reports of joint pain, which may be severe, in those taking DPP4 inhibitors. Onset of symptoms following initiation of treatment may be rapid or may occur after longer periods. Discontinuation of therapy should be considered in individuals who present with or experience an exacerbation of joint symptoms during treatment with saxagliptin.

Note: Diabetes MedsCheck with counselling on side effect profile and referral to healthcare team if suspected.

Pharmacokinetic Properties Summary
  • The results of bioequivalence studies in individuals without diabetes demonstrated that SAXAGLIPTIN/METFORMIN XR combination tablets are bioequivalent to coadministration of corresponding doses of saxagliptin and metformin hydrochloride modified release as individual tablets.
  • The following statements reflect the pharmacokinetic properties of the individual active substances of SAXAGLIPTIN/METFORMIN XR.

 

Saxagliptin:. The inhibition of plasma DPP-4 activity by saxagliptin for at least 24 hours after oral administration is due to high potency, high affinity, and extended binding to the active site. Appreciable accumulation was observed with repeated once-daily dosing at any dose level. No dose- and time-dependence was observed in the clearance of saxagliptin and its major metabolite over 14 days of once-daily dosing with saxagliptin at doses ranging from 2.5 mg to 400 mg.

Metformin hydrochloride: Metformin extended release Cmax is achieved with a median value of 7 hours. The extent of metformin absorption from the metformin extended-release tablet is increased by approximately 50% when given with food. Metformin is excreted unchanged in the urine and does not undergo hepatic metabolism.

Absorption:

– Saxagliptin: Based on food effects studies, saxagliptin may be administered with or without food.

– Metformin hydrochloride: Following a single oral dose of metformin extended release, Cmax is achieved with a median value of 7 hours and a range of 4 to 8 hours.

Distribution:

– Saxagliptin:, Changes in blood protein levels in various disease states (e.g., renal or hepatic impairment) are not expected to alter the disposition of saxagliptin.

– Metformin hydrochloride:. Metformin is negligibly bound to plasma proteins.

Metabolism:

– Saxagliptin: The metabolism of saxagliptin is primarily mediated by cytochrome P450 3A4/5 (CYP3A4/5). The major metabolite of saxagliptin is also a reversible, competitive DPP-4 inhibitor, half as potent as saxagliptin.

– Metformin hydrochloride: Metformin is excreted unchanged in the urine and does not undergo hepatic metabolism.

Excretion:

– Saxagliptin: Saxagliptin is eliminated by both renal and hepatic pathways.

– Metformin hydrochloride: Renal clearance is approximately 3.5 times greater than creatinine clearance, which indicates that tubular secretion is the major route of metformin elimination.

More Information

For further information on SAXAGLIPTIN/METFORMIN XR please see

https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2013-PI-02314-1