Dapagliflozin, Saxagliptin and Metformin HCl
Overall, the pharmacokinetics of dapagliflozin, saxagliptin, and metformin were not affected in a clinically relevant manner when administered as QTERNMET XR.
Saxagliptin
The pharmacokinetics of saxagliptin and its active metabolite, 5-hydroxy saxagliptin, were similar in healthy subjects and in patients with type 2 diabetes mellitus. The Cmax and AUC values of saxagliptin and its active metabolite increased proportionally in the 2.5 to 400 mg dose range. Following a 5 mg single oral dose of saxagliptin to healthy subjects, the mean plasma AUC values for saxagliptin and its active metabolite were 78 ng•h/mL and 214 ng•h/mL, respectively. The corresponding plasma Cmax values were 24 ng/mL and 47 ng/mL, respectively. The average variability (%CV) for AUC and Cmax for both saxagliptin and its active metabolite was less than 25%.
No appreciable accumulation of either saxagliptin or its active metabolite was observed with repeated once daily dosing at any dose level. No dose- and time-dependence were observed in the clearance of saxagliptin and its active metabolite over 14 days of once daily dosing with saxagliptin at doses ranging from 2.5 to 400 mg.
Absorption
Dapagliflozin
Following oral administration of dapagliflozin, the maximum plasma concentration (Cmax) is usually attained within 2 hours under fasting state. The Cmax and AUC values increase dose proportionally with increase in dapagliflozin dose in the therapeutic dose range. The absolute oral bioavailability of dapagliflozin following the administration of a 10 mg dose is 78%. Administration of QTERNMET XR with a standard meal decreases dapagliflozin Cmax by up to 39% and prolongs Tmax by up to 2 hours, but food does not alter AUC as compared with the fasted state.
Saxagliptin
The median time to maximum concentration (Tmax) following the 5 mg once daily dose was up to 2 hours for saxagliptin and 4 hours for its active metabolite. Administration of QTERNMET XR with a standard meal resulted in an increase in Tmax of saxagliptin by up to 1.5 h and an up to 16% decrease in saxagliptin Cmax as compared to fasted conditions. There was an up to 10% increase in the AUC of saxagliptin when given with a meal as compared to fasted conditions.
Metformin HCl
Administration of QTERNMET XR with a standard meal resulted in an increase in Tmax of metformin by 2 h and no effect on metformin Cmax as compared to fasted conditions. There was an up to 15% increase in the AUC of saxagliptin when given with a meal as compared to fasted conditions. Both high and low-fat meals had the same effect on the pharmacokinetics of metformin extended-release.
Peak plasma levels of metformin extended-release tablets are approximately 20% lower compared to the same dose of metformin immediate-release tablets, however, the extent of absorption (as measured by AUC) is similar between extended-release tablets and immediate-release tablets.
At steady state, the AUC and Cmax are less than dose proportional for metformin extended-release within the range of 500 to 2000 mg. After repeated administration of metformin extended-release, metformin did not accumulate in plasma.
Distribution
Dapagliflozin
Dapagliflozin is approximately 91% protein bound. Protein binding is not altered in patients with renal or hepatic impairment.
Saxagliptin
The in vitro protein binding of saxagliptin and its active metabolite in human serum is negligible. Therefore, 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 HCl
Distribution studies with extended-release metformin have not been conducted; however, the apparent volume of distribution (V/F) of metformin following single oral doses of immediate-release metformin 850 mg averaged 654 ± 358 L. Metformin is negligibly bound to plasma proteins. Metformin partitions into erythrocytes, most likely as a function of time.
Metabolism
Dapagliflozin
The metabolism of dapagliflozin is primarily mediated by UGT1A9; CYP-mediated metabolism is a minor clearance pathway in humans. Dapagliflozin is extensively metabolized, primarily to yield dapagliflozin 3-O-glucuronide, which is an inactive metabolite. Dapagliflozin 3-O-glucuronide accounted for 61% of a 50 mg [14C]-dapagliflozin dose and is the predominant drug-related component in human plasma.
Saxagliptin
The metabolism of saxagliptin is primarily mediated by cytochrome P450 3A4/5 (CYP3A4/5). The major metabolite of saxagliptin is also a DPP-4 inhibitor, which is one-half as potent as saxagliptin. Therefore, strong CYP3A4/5 inhibitors and inducers will alter the pharmacokinetics of saxagliptin and its active metabolite [see DRUG INTERACTIONS (7)].
Metformin HCl
Intravenous single-dose studies in healthy subjects demonstrate that metformin is excreted unchanged in the urine and does not undergo hepatic metabolism (no metabolites have been identified in humans) or biliary excretion.
Metabolism studies with extended-release metformin tablets have not been conducted.
Elimination
Dapagliflozin
Dapagliflozin and related metabolites are primarily eliminated via the renal pathway. Following a single 50 mg dose of [14C]-dapagliflozin, 75% and 21% total radioactivity is excreted in urine and feces, respectively. In urine, less than 2% of the dose is excreted as parent drug. In feces, approximately 15% of the dose is excreted as parent drug. The mean plasma terminal half-life (t1/2) for dapagliflozin is approximately 12.9 hours following a single oral dose of dapagliflozin 10 mg.
Saxagliptin
Saxagliptin is eliminated by both renal and hepatic pathways. Following a single 50 mg dose of [14C]-saxagliptin, 24%, 36%, and 75% of the dose was excreted in the urine as saxagliptin, its active metabolite, and total radioactivity, respectively. The average renal clearance of saxagliptin (~230 mL/min) was greater than the average estimated glomerular filtration rate (~120 mL/min), suggesting some active renal excretion. A total of 22% of the administered radioactivity was recovered in feces representing the fraction of the saxagliptin dose excreted in bile and/or unabsorbed drug from the gastrointestinal tract. Following a single oral dose of saxagliptin 5 mg to healthy subjects, the mean plasma terminal half-life (t1/2) for saxagliptin and its active metabolite was 2.5 and 3.1 hours, respectively.
Metformin HCl
Renal clearance is approximately 3.5 times greater than creatinine clearance, which indicates that tubular secretion is the major route of metformin elimination. Following oral administration, approximately 90% of the absorbed drug is eliminated via the renal route within the first 24 hours, with a plasma elimination half-life of approximately 6.2 hours. In blood, the elimination half-life is approximately 17.6 hours, suggesting that the erythrocyte mass may be a compartment of distribution.
Specific Populations
Effects of Age, Gender, Race, and Body Weight on Pharmacokinetics
Based on a population pharmacokinetic analysis, age, gender, race, and body weight do not have a clinically meaningful effect on the pharmacokinetics of dapagliflozin and saxagliptin.
Renal Impairment
Dapagliflozin: At steady state (20 mg once daily dapagliflozin for 7 days), patients with type 2 diabetes with mild, moderate, or severe renal impairment (as determined by eGFR) had geometric mean systemic exposures of dapagliflozin that were 45%, 2.04-fold, and 3.03-fold higher, respectively, as compared to patients with type 2 diabetes with normal renal function. Higher systemic exposure of dapagliflozin in patients with type 2 diabetes mellitus with renal impairment did not result in a correspondingly higher 24-hour urinary glucose excretion. The steady-state 24-hour urinary glucose excretion in patients with type 2 diabetes and mild, moderate and severe renal impairment was 42%, 80% and 90% lower, respectively, than patients with type 2 diabetes with normal renal function. The impact of hemodialysis on dapagliflozin exposure is not known [see DOSAGE AND ADMINISTRATION (2.3), WARNINGS AND PRECAUTIONS (5.6) and USE IN SPECIFIC POPULATIONS (8.6)].
Saxagliptin: A single-dose, open-label study was conducted to evaluate the pharmacokinetics of saxagliptin (10 mg dose) in subjects with varying degrees of chronic renal impairment compared to subjects with normal renal function. The 10 mg dosage is not an approved dosage. The degree of renal impairment did not affect Cmax of saxagliptin or its metabolite. In subjects with moderate renal impairment (eGFR 30 to less than 45 mL/min/1.73 m2), severe renal impairment (eGFR 15 to less than 30 mL/min/1.73 m2) and ESRD patient on hemodialysis, the AUC values of saxagliptin or its active metabolite were >2 fold higher than AUC values in subjects with normal renal function. QTERNMET XR is contraindicated in patients with an eGFR less than 45 mL/min/1.73 m2, ESRD, or on dialysis.
Metformin HCl: In patients with decreased renal function, the plasma and blood half-life of metformin is prolonged and the renal clearance is decreased [see CONTRAINDICATIONS (4) and WARNINGS AND PRECAUTIONS (5.1)].
Hepatic Impairment
Dapagliflozin: In subjects with mild and moderate hepatic impairment (Child-Pugh classes A and B), mean Cmax and AUC of dapagliflozin were up to 12% and 36% higher, respectively, as compared to healthy matched control subjects following single-dose administration of 10 mg dapagliflozin. These differences were not considered to be clinically meaningful. In patients with severe hepatic impairment (Child-Pugh class C), mean Cmax and AUC of dapagliflozin were up to 40% and 67% higher, respectively, as compared to healthy matched controls.
Saxagliptin: In subjects with hepatic impairment (Child-Pugh classes A, B, and C), mean Cmax and AUC of saxagliptin were up to 8% and 77% higher, respectively, compared to healthy matched controls following administration of a single 10 mg dose of saxagliptin. The 10 mg dosage is not an approved dosage. The corresponding Cmax and AUC of the active metabolite were up to 59% and 33% lower, respectively, compared to healthy matched controls. These differences are not considered to be clinically meaningful.
Metformin HCl: No pharmacokinetic studies of metformin have been conducted in patients with hepatic impairment [see DOSAGE AND ADMINISTRATION (2.3), WARNINGS AND PRECAUTIONS (5.1) and USE IN SPECIFIC POPULATIONS (8.7)].
Pediatric
Pharmacokinetics of QTERNMET XR in the pediatric population has not been studied.
Drug Interactions
Specific pharmacokinetic drug interaction studies with QTERNMET XR have not been performed although such studies have been conducted with the individual dapagliflozin, saxagliptin and metformin components.
Dapagliflozin
In Vitro Assessment of Drug Interactions
The metabolism of dapagliflozin is primarily via glucuronide conjugation mediated by UDP glucuronosyltransferase 1A9 (UGT1A9).
In in vitro studies, dapagliflozin and dapagliflozin 3-O-glucuronide neither inhibited CYP 1A2, 2C9, 2C19, 2D6, or 3A4, nor induced CYP 1A2, 2B6, or 3A4. Dapagliflozin is a weak substrate of the P-glycoprotein (P-gp) active transporter, and dapagliflozin 3-O-glucuronide is a substrate for the OAT3 active transporter. Dapagliflozin or dapagliflozin 3-O-glucuronide did not meaningfully inhibit P-gp, OCT2, OAT1, or OAT3 active transporters. Overall, dapagliflozin is unlikely to affect the pharmacokinetics of concurrently administered medications that are P-gp, OCT2, OAT1, or OAT3 substrates.
Effects of Other Drugs on Dapagliflozin
Table 3 shows the effect of coadministered drugs on the pharmacokinetics of dapagliflozin.
Table 3: Effects of Coadministered Drugs on Dapagliflozin Systemic ExposureCoadministered Drug (Dose Regimen) | Dapagliflozin (Dose Regimen) | Dapagliflozin |
Change in AUC | Change in Cmax
|
Oral Antidiabetic Agents |
Metformin (1000 mg) | 20 mg | ↓1% | ↓7% |
Pioglitazone (45 mg) | 50 mg | 0% | ↑9% |
Sitagliptin (100 mg) | 20 mg | ↑8% | ↓4% |
Glimepiride (4 mg) | 20 mg | ↓1% | ↑1% |
Voglibose (0.2 mg three times daily) | 10 mg | ↑1% | ↑4% |
Saxagliptin (5 mg single dose) | 10 mg (single dose) | ↓2% | ↓6% |
Other Medications |
Hydrochlorothiazide (25 mg) | 50 mg | ↑7% | ↓1% |
Bumetanide (1 mg) | 10 mg once daily for 7 days | ↑5% | ↑8% |
Valsartan (320 mg) | 20 mg | ↑2% | ↓12% |
Simvastatin (40 mg) | 20 mg | ↓1% | ↓2% |
Anti-infective Agent |
Rifampin (600 mg once daily for 6 days) | 10 mg | ↓22% | ↓7% |
Nonsteroidal Anti-inflammatory Agent |
Mefenamic Acid (loading dose of 500 mg followed by 14 doses of 250 mg every 6 hours) | 10 mg | ↑51% | ↑13% |
Effects of Dapagliflozin on Other Drugs
Table 4 shows the effect of dapagliflozin on other coadministered drugs. Dapagliflozin did not meaningfully affect the pharmacokinetics of the coadministered drugs.
Table 4: Effects of Dapagliflozin on the Systemic Exposures of Coadministered DrugsCoadministered Drug (Dose Regimen) | Dapagliflozin (Dose Regimen) | Coadministered Drug |
Change in AUC | Change in Cmax
|
Oral Antidiabetic Agents |
Metformin (1000 mg) | 20 mg | 0% | ↓5% |
Pioglitazone (45 mg) | 50 mg | 0% | ↓7% |
Sitagliptin (100 mg) | 20 mg | ↑1% | ↓11% |
Glimepiride (4 mg) | 20 mg | ↑13% | ↑4% |
Other Medications |
Hydrochlorothiazide (25 mg) | 50 mg | ↓1% | ↓5% |
Bumetanide (1 mg) | 10 mg once daily for 7 days | ↑13% | ↑13% |
Valsartan (320 mg) | 20 mg | ↑5% | ↓6% |
Simvastatin (40 mg) | 20 mg | ↑19% | ↓6% |
Digoxin (0.25 mg) | 20 mg loading dose then 10 mg once daily for 7 days | 0% | ↓1% |
Warfarin (25 mg) S-warfarin R-warfarin | 20 mg loading dose then 10 mg once daily for 7 days | ↑3% ↑6% | ↑7% ↑8% |
Saxagliptin
In Vitro Assessment of Drug Interactions
The metabolism of saxagliptin is primarily mediated by CYP3A4/5.
In in vitro studies, saxagliptin and its active metabolite did not inhibit CYP1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, or 3A4, or induce CYP1A2, 2B6, 2C9, or 3A4. Therefore, saxagliptin is not expected to alter the metabolic clearance of coadministered drugs that are metabolized by these enzymes. Saxagliptin is a P-glycoprotein (P-gp) substrate but is not a significant inhibitor or inducer of P-gp.
Effects of Other Drugs on Saxagliptin and its Active Metabolite, 5-hydroxy Saxagliptin
Table 5: Effect of Coadministered Drugs on Systemic Exposures of Saxagliptin and its Active Metabolite, 5-hydroxy SaxagliptinCoadministered Drug | Dosage of Coadministered Drug | Dosage of Saxagliptin | Saxagliptin |
| Change in AUC | Change in Cmax
|
Metformin | 1000 mg | 100 mg | saxagliptin 5-hydroxy saxagliptin | ↓2% ↓1% | ↓21% ↓12% |
Glyburide | 5 mg | 10 mg | saxagliptin 5-hydroxy saxagliptin | ↓2% ND | ↑8% ND |
Pioglitazone
| 45 mg QD for 10 days | 10 mg QD for 5 days | saxagliptin 5-hydroxy saxagliptin | ↑11% ND | ↑11% ND |
Dapagliflozin | 10 mg single dose | 5 mg single dose | saxagliptin 5-hydroxy saxagliptin | ↓1% ↑9% | ↓7% ↑6% |
Digoxin | 0.25 mg q6h first day followed by q12h second day followed by QD for 5 days | 10 mg QD for 7 days | saxagliptin 5-hydroxy saxagliptin | ↑5% ↑6% | ↓1% ↑2% |
Simvastatin | 40 mg QD for 8 days | 10 mg QD for 4 days | saxagliptin 5-hydroxy saxagliptin | ↑12% ↑2% | ↑21% ↑8% |
Diltiazem | 360 mg LA QD for 9 days | 10 mg | saxagliptin 5-hydroxy saxagliptin | ↑109% ↓34% | ↑63% ↓43% |
Rifampin
| 600 mg QD for 6 days | 5 mg | saxagliptin 5-hydroxy saxagliptin | ↓76% ↑3% | ↓53% ↑39% |
Omeprazole | 40 mg QD for 5 days | 10 mg | saxagliptin 5-hydroxy saxagliptin | ↑13% ND | ↓2% ND |
Aluminum hydroxide + magnesium hydroxide + simethicone | aluminum hydroxide: 2400 mg magnesium hydroxide: 2400 mg simethicone: 240 mg | 10 mg | saxagliptin 5-hydroxy saxagliptin | ↓3% ND | ↓26% ND |
Famotidine | 40 mg | 10 mg | saxagliptin 5-hydroxy saxagliptin | ↑3% ND | ↑14% ND |
Saxagliptin coadministered with strong CYP3A4/5 inhibitors [see DRUG INTERACTIONS (7) and DOSAGE AND ADMINISTRATION (2.4)]: |
Ketoconazole | 200 mg BID for 9 days | 100 mg | saxagliptin 5-hydroxy saxagliptin | ↑145% ↓88% | ↑62% ↓95% |
Ketoconazole | 200 mg BID for 7 days | 20 mg | saxagliptin 5-hydroxy saxagliptin | ↑267% ND | ↑144% ND |
ND=not determined; QD=once daily; q6h=every 6 hours; q12h=every 12 hours; BID=twice daily; LA=long acting. |
Effects of Saxagliptin on Other Drugs
Table 6: Effect of Saxagliptin on Systemic Exposures of Coadministered DrugsCoadministered Drug | Dosage of Coadministered Drug | Dosage of Saxagliptin | Coadministered Drug |
| Change in AUC | Change in Cmax
|
Metformin | 1000 mg | 100 mg | metformin | ↑20% | ↑9% |
Glyburide | 5 mg | 10 mg | glyburide | ↑6% | ↑16% |
Pioglitazone
| 45 mg QD for 10 days | 10 mg QD for 5 days | pioglitazone hydroxy-pioglitazone | ↑8% ND | ↑14% ND |
Digoxin | 0.25 mg q6h first day followed by q12h second day followed by QD for 5 days | 10 mg QD for 7 days | digoxin | ↑6% | ↑9% |
Simvastatin | 40 mg QD for 8 days | 10 mg QD for 4 days | simvastatin simvastatin acid | ↑4% ↑16% | ↓12% 0% |
Diltiazem | 360 mg LA QD for 9 days | 10 mg | diltiazem | ↑10% | ↑16% |
Ketoconazole | 200 mg BID for 9 days | 100 mg | ketoconazole | ↓13% | ↓16% |
Ethinyl estradiol and Norgestimate | ethinyl estradiol 0.035 mg and norgestimate 0.250 mg for 21 days | 5 mg QD for 21 days | ethinyl estradiol norelgestromin norgestrel | ↑7% ↑10% ↑13% | ↓2% ↑9% ↑17% |
ND=not determined; QD=once daily; q6h=every 6 hours; q12h=every 12 hours; BID=twice daily; LA=long acting. |
Metformin
Effects of Other Drugs on Metformin
Table 7: Effect of Coadministered Drug on Plasma Metformin Systemic ExposureCoadministered Drug | Dose of Coadministered Drug | Dose of Metformin | Metformin |
Change in AUC | Change in Cmax
|
Glyburide | 5 mg | 850 mg | ↓9%
| ↓7%
|
Furosemide | 40 mg | 850 mg | ↑15%
| ↑22%
|
Nifedipine | 10 mg | 850 mg | ↑9% | ↑20% |
Propranolol | 40 mg | 850 mg | ↓10% | ↓6% |
Ibuprofen | 400 mg | 850 mg | ↑5%
| ↑7%
|
Drugs eliminated by renal tubular secretion may increase the accumulation of metformin [see DRUG INTERACTIONS (7)]. |
Cimetidine | 400 mg | 850 mg | ↑40% | ↑60% |
Effects of Metformin on Other Drugs
Table 8: Effect of Metformin on Coadministered Drug Systemic ExposureCoadministered Drug | Dose of Coadministered Drug | Dose of Metformin | Coadministered Drug |
Change in AUC | Change in Cmax
|
Glyburide | 5 mg | 850 mg | ↓22%
| ↓37%
|
Furosemide | 40 mg | 850 mg | ↓12%
| ↓31%
|
Nifedipine | 10 mg | 850 mg | ↑10%
| ↑8% |
Propranolol | 40 mg | 850 mg | ↑1%
| ↑2% |
Ibuprofen | 400 mg | 850 mg | ↓3%
| ↑1%
|
Cimetidine | 400 mg | 850 mg | ↓5%
| ↑1% |