EMPAGLIFLOZIN; LINAGLIPTIN; METFORMIN HYDROCHLORIDE
Clinical safety rating: safe
Alcohol and contrast dye can increase risk of lactic acidosis Can cause lactic acidosis a rare but serious metabolic complication.
Empagliflozin is a sodium-glucose cotransporter-2 (SGLT2) inhibitor that reduces renal glucose reabsorption, increasing urinary glucose excretion. Linagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor that prolongs incretin hormone activity, enhancing glucose-dependent insulin secretion and suppressing glucagon release. Metformin hydrochloride decreases hepatic glucose production, reduces intestinal glucose absorption, and improves insulin sensitivity.
| Metabolism | Empagliflozin: glucuronidation (UGT2B7, UGT1A3, UGT1A8, UGT1A9); Linagliptin: minimal metabolism, primarily excreted unchanged; Metformin: not metabolized, excreted unchanged in urine. |
| Excretion | Empagliflozin: ~54% renal (unchanged and metabolites), ~41% fecal (biliary excretion). Linagliptin: ~85% fecal (enterohepatic recycling), ~5% renal. Metformin: ~90% renal (unchanged), ~10% fecal. |
| Half-life | Empagliflozin: 12.4 hours (terminal), supports once-daily dosing. Linagliptin: 131-188 hours (effective half-life 12-24 hours due to DPP-4 binding), once-daily dosing. Metformin: 6.2 hours (immediate-release), 9-10 hours (extended-release); requires multiple daily dosing. |
| Protein binding | Empagliflozin: 86.2% (to plasma proteins). Linagliptin: 75-99% (concentration-dependent, mainly to albumin and alpha-1-acid glycoprotein). Metformin: <5% (negligible binding to plasma proteins). |
| Volume of Distribution | Empagliflozin: 73.5 L (1.05 L/kg) – extensive tissue distribution. Linagliptin: 111-1,710 L (1.6-24.4 L/kg) – large due to extensive tissue binding. Metformin: 654 L (9.3 L/kg) – extensive distribution into tissues (erythrocytes, liver, kidneys). |
| Bioavailability | Empagliflozin: 78% (oral). Linagliptin: ~30% (oral, due to first-pass metabolism). Metformin: 50-60% (immediate-release), ~50% (extended-release); under fasting conditions. |
| Onset of Action | Empagliflozin: 1-2 hours (initial urinary glucose excretion). Linagliptin: 1 hour (DPP-4 inhibition, peak insulin secretion within 2 hours). Metformin: 30-60 minutes (immediate-release), variable (extended-release); peak effect at 2-4 hours post-dose. |
| Duration of Action | Empagliflozin: >24 hours (SGLT2 inhibition sustained). Linagliptin: 24 hours (once-daily coverage of DPP-4). Metformin: 8-12 hours (immediate-release), 24 hours (extended-release); with renal function monitoring. |
| Molecular Weight | Metformin hydrochloride: 165.62 Da; Empagliflozin: 450.91 Da; Linagliptin: 472.54 Da |
Adult: One tablet orally twice daily. Each tablet contains empagliflozin 5 mg or 12.5 mg, linagliptin 2.5 mg, and metformin hydrochloride 500 mg, 850 mg, or 1000 mg. Dose should be individualized based on current therapy and tolerability, with maximum empagliflozin dose 25 mg/day, linagliptin 5 mg/day, and metformin 2000 mg/day.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | eGFR ≥45 mL/min/1.73 m²: No dose adjustment. eGFR 30-44: Contraindicated due to metformin component. eGFR <30: Contraindicated (all components). |
| Liver impairment | Child-Pugh Class A: No dose adjustment. Child-Pugh Class B or C: Contraindicated due to metformin risk of lactic acidosis. |
| Pediatric use | Safety and efficacy not established; no recommended dose. |
| Geriatric use | No specific dose adjustment based on age alone. Assess renal function; eGFR should be ≥45 mL/min/1.73 m² before initiation. Caution with volume depletion and risk of lactic acidosis. Monitor renal function more frequently. |
| 1st trimester | Metformin: Limited human data; generally considered acceptable for use in women with type 2 diabetes or gestational diabetes if insulin not feasible. Empagliflozin and linagliptin: Insufficient human data; animal studies show no major teratogenicity but risk cannot be excluded. Avoid if possible in first trimester. |
| 2nd trimester | Metformin: Crosses placenta; limited data show no clear increase in malformations. Empagliflozin and linagliptin: Insufficient data; potential risk of adverse fetal effects due to SGLT2 inhibition (empagliflozin) and DPP-4 inhibition (linagliptin). Avoid unless benefit outweighs risk. |
| 3rd trimester | Metformin: Crosses placenta; may increase risk of neonatal hypoglycemia if used near term. Empagliflozin: Not recommended; potential for fetal renal effects and polyhydramnios. Linagliptin: Insufficient data; avoid. All: No adequate well-controlled studies in pregnant women. |
Clinical note
Alcohol and contrast dye can increase risk of lactic acidosis Can cause lactic acidosis a rare but serious metabolic complication.
| FDA category | Human |
■ FDA Black Box Warning
Lactic acidosis associated with metformin accumulation, especially in patients with renal impairment, acute decompensated heart failure, or other conditions predisposing to hypoxia and acidosis.
| Common Effects | Diarrhea |
| Serious Effects |
Metformin: Severe renal impairment (eGFR <30 mL/min/1.73 m²), acute or chronic metabolic acidosis, hypersensitivity to metformin, acute kidney injury, severe infection, shock, hypoxemia, hepatic impairment, history of lactic acidosis, use of iodinated contrast agents (temporary discontinuation required).Empagliflozin: Severe renal impairment (eGFR <30 mL/min/1.73 m²), end-stage renal disease, dialysis, hypersensitivity to empagliflozin, history of serious hypersensitivity reaction (e.g., anaphylaxis, angioedema), type 1 diabetes (not indicated).Linagliptin: Type 1 diabetes, diabetic ketoacidosis, hypersensitivity to linagliptin, history of serious hypersensitivity reaction.
| Precautions | Lactic acidosis (metformin), Pancreatitis (linagliptin), Acute kidney injury (empagliflozin, metformin), Volume depletion/hypotension (empagliflozin), Urosepsis/pyelonephritis (empagliflozin), Necrotizing fasciitis of perineum (empagliflozin), Hypoglycemia with insulin secretagogues/insulin, Vitamin B12 deficiency (metformin), Risk of acute gout (empagliflozin) |
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| Placental transfer |
| Metformin: Crosses placenta (classed as FDA pregnancy category B; human data demonstrate placental transfer). Empagliflozin: Animal studies show placental transfer; limited human data. Linagliptin: Animal studies show placental transfer; limited human data. |
| Breastfeeding | Metformin: Excreted into breast milk in small amounts; considered compatible with breastfeeding by most sources. Empagliflozin: Unknown if excreted; potential for adverse effects on the nursing infant (e.g., renal effects). Linagliptin: Unknown if excreted; limited data. Caution advised; alternative agents preferred. |
| Lactation Rating | L3 (Metformin); L4 (Empagliflozin); L4 (Linagliptin) |
| Teratogenic Risk | First trimester: Metformin not associated with major malformations; linagliptin limited human data, animal studies show no teratogenicity; empagliflozin animal studies show renal toxicity in late gestation. Second and third trimesters: Metformin may increase risk of preterm birth and low birth weight; linagliptin unknown; empagliflozin contraindicated due to risk of neonatal renal impairment and oligohydramnios. |
| Fetal Monitoring | Maternal: blood glucose, HbA1c, renal function, liver function, vitamin B12 (metformin). Fetal: ultrasound for growth and amniotic fluid volume (empagliflozin), neonatal monitoring for hypoglycemia, renal function (empagliflozin). |
| Fertility Effects | Metformin may improve ovulation in polycystic ovary syndrome (PCOS) through reduced hyperinsulinemia; linagliptin and empagliflozin have no known significant effects on fertility in humans. |
| Food/Dietary | Alcohol intake increases risk of lactic acidosis with metformin. Avoid excessive alcohol. Take metformin with meals to minimize gastrointestinal upset. No specific food interactions for empagliflozin or linagliptin. |
| Clinical Pearls | Triple therapy for type 2 diabetes. Empagliflozin lowers HbA1c and reduces cardiovascular mortality in patients with established CVD. Linagliptin is weight-neutral and renally safe. Metformin is first-line. Monitor for eGFR decline, volume depletion, and rare diabetic ketoacidosis (euglycemic DKA). Check renal function before initiation and periodically. Avoid in severe renal impairment (eGFR <30). |
| Patient Advice | Take with meals to reduce gastrointestinal side effects. · Report symptoms of urinary tract infections or genital mycotic infections. · Seek immediate medical attention for signs of diabetic ketoacidosis: nausea, vomiting, abdominal pain, confusion, excessive fatigue. · Maintain adequate hydration to prevent hypovolemia. · Do not skip meals, especially if taking insulin or sulfonylureas, to avoid hypoglycemia. · Regularly monitor blood glucose and HbA1c. · Inform healthcare provider if you become pregnant or plan to breastfeed. |