Treatment Escalation for Type 2 Diabetes on Maximum Metformin

First-Line Add-On Therapy: SGLT-2 Inhibitors vs GLP-1 Agonists

The American College of Physicians provides a strong recommendation (high-certainty evidence) to add either an SGLT-2 inhibitor or GLP-1 agonist to metformin when glycemic control is inadequate, as these two drug classes uniquely reduce all-cause mortality and major cardiovascular events 1
SGLT-2 inhibitors reduce hospitalization for congestive heart failure more effectively than any other oral agent, and are recommended for patients with heart failure or at risk of heart failure 1
The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend SGLT-2 inhibitors for patients with diabetes and kidney disease (eGFR ≥30 mL/min/1.73 m²), as they slow CKD progression 2, 1
SGLT-2 inhibitors reduce major adverse cardiovascular events (MACE) and all-cause mortality, and are recommended for patients with established cardiovascular disease 1
GLP-1 agonists specifically reduce stroke risk beyond other cardiovascular benefits, and are recommended for patients with elevated stroke risk 1
GLP-1 agonists produce greater weight reduction than SGLT-2 inhibitors, and are recommended when weight loss is a treatment priority 1
GLP-1 agonists provide benefits comparable to SGLT-2 inhibitors in reducing all-cause mortality and MACE 1
GLP-1 agonists do not cause genital mycotic infections, a common side effect of SGLT-2 inhibitors, and are recommended for patients who prefer to avoid this side effect 3

The American College of Physicians issues a strong recommendation against adding a DPP-4 inhibitor as second-line therapy, based on high-certainty evidence showing no mortality or morbidity benefit 1
DPP-4 inhibitors do not reduce death, cardiovascular events, or hospitalizations, despite lowering HbA1c by approximately 0.5-0.8% 3

Initiate basal insulin if HbA1c ≥10% at any point, or if blood glucose is markedly elevated with symptoms (polyuria, polydipsia, weight loss) 3
Consider insulin-based therapy if HbA1c remains above target after 3 months on dual therapy with metformin and SGLT-2 inhibitor or GLP-1 agonist 3

Reduce or discontinue sulfonylureas or insulin when adding an SGLT-2 inhibitor or GLP-1 agonist to prevent severe hypoglycemia, as both newer drug classes carry minimal hypoglycemia risk when used with metformin alone 1, 3
Self-monitoring of blood glucose is typically unnecessary when using metformin plus SGLT-2 inhibitor or GLP-1 agonist, as neither combination causes hypoglycemia 1
Continue metformin at the current dose (2000mg/day) when adding the second agent, unless contraindications develop, and consider dose reduction to half the maximum dose if eGFR falls below 30-44 mL/min/1.73 m² 2
Aim for HbA1c between 7-8% for most adults, and reassess glycemic control after 3 months on dual therapy 1, 3

Do not wait indefinitely on failing metformin monotherapy - add a second agent after 3 months if HbA1c is not at goal 3
Do not choose DPP-4 inhibitors based solely on HbA1c reduction, as outcomes that matter (death, MI, stroke) are not improved 1
Do not continue full-dose sulfonylureas or insulin when adding SGLT-2i or GLP-1 agonist without dose reduction, to prevent severe hypoglycemia 1
Do not stop metformin when adding a second agent, unless eGFR falls below 30 mL/min/1.73 m² or other contraindications emerge 2

Discuss medication costs with patients and explore patient assistance programs when cost is prohibitive, as SGLT-2 inhibitors and GLP-1 agonists are currently not available as generics and may be more expensive than older agents 1

The American College of Physicians recommends metformin as the first-line therapy for most patients with type 2 diabetes, unless contraindicated or not tolerated 4, 5
Long-term metformin use may cause vitamin B12 deficiency; periodic testing is recommended, especially in patients with anemia or peripheral neuropathy 4, 5

The American College of Physicians strongly recommends SGLT-2 inhibitors as add-on therapy to metformin when glycemic control is inadequate 6, 7
SGLT-2 inhibitors provide significant benefits in reducing all-cause mortality 7, 8
SGLT-2 inhibitors provide significant benefits in reducing major adverse cardiovascular events (MACE) 7, 9
SGLT-2 inhibitors provide significant benefits in reducing progression of chronic kidney disease 7, 10
SGLT-2 inhibitors provide significant benefits in reducing hospitalization due to congestive heart failure 7, 11
SGLT-2 inhibitors should be prioritized in patients with heart failure or chronic kidney disease 7, 12

The American College of Physicians strongly recommends GLP-1 receptor agonists as add-on therapy to metformin when glycemic control is inadequate 6, 7
GLP-1 receptor agonists provide significant benefits in reducing all-cause mortality 7, 8
GLP-1 receptor agonists provide significant benefits in reducing major adverse cardiovascular events (MACE) 7, 9
GLP-1 receptor agonists provide significant benefits in reducing stroke 7, 10
GLP-1 receptor agonists should be prioritized in patients with increased stroke risk or when weight loss is an important treatment goal 7, 12

For newly diagnosed patients with severe hyperglycemia or who are symptomatic, consider initiating insulin therapy with or without additional agents 4, 5
When SGLT-2 inhibitors or GLP-1 agonists provide adequate glycemic control, consider reducing or discontinuing sulfonylureas or long-acting insulins to minimize hypoglycemia risk 7, 10

Target HbA1c levels between 7% and 8% for most adults with type 2 diabetes 7, 9
Consider deintensifying treatment in patients with HbA1c <6.5% 7, 10
Self-monitoring of blood glucose might be unnecessary in patients on metformin combined with either SGLT-2 inhibitors or GLP-1 agonists 7, 11

Individualize glycemic goals based on hypoglycemia risk, life expectancy, diabetes duration, vascular complications, and comorbidities 7, 8
Sulfonylureas and long-acting insulins are inferior to SGLT-2 inhibitors and GLP-1 agonists for mortality and morbidity outcomes but may still have value for glycemic control 7, 10
The benefits and harms of using multiple add-on treatments beyond the initial combination are not well established 7, 12