Table 3

Oral antidiabetic drugs: pros and cons in older adults

Antidiabetic drugMechanism of actionEffect on decreasing
HbA1c
Pros (benefits) in older adultsCons (side effects in older adultsPractical tips
MetforminDecreases gluconeogenesis and increases glycogenolysis1%–2%No hypoglycemia
No weight gain
Low cost
Positive effect on lipids
Decreases macrovascular complications
Lactic acidosis in severe CKD
GI symptoms
Take on full stomach
Start low dose to minimize GI side effects and titrate up slowly
Cautiously in older adults with increased risk of lactic acidosis
Insulin secretagogues (SUs and glinides)Stimulates insulin secretion by inducing a B-cell interaction with a SU receptor0.5%–1.0%Once a day
Works fast
HypoglycemiaNon preferred in older adults because of the risk of hypoglycemia
Alpha glucosidase inhibitorsSlow carbohydrate absorption by blocking alpha glycosidase and increase GLP-1 level0.5%–1.0%Improves postprandial BGGI symptomsTo be taken with first bite of food
ThiazolidinedionePPARγ agonist and regulate carbohydrate and lipid metabolism, enhance tissue response to insulin0.9%–1.5%No hypoglycemia when used as monotherapySlow onset of action
HF
Fluid retention
Don’t use if patient has osteoporosis or macular degeneration, which are common in older adults.
DPP-4 inhibitorsStimulates insulin secretion and inhibits glucagon secretion by increasing endogenous GLP-11%No hypoglycemia when used as monotherapyRisk of hypoglycemia if used with SUWell-tolerated and low risk of hypoglycemia
Can be used even in the presence of CKD
Avoid if there is history of pancreatitis.
GLP-1 receptor agonistsStimulate insulin secretion, inhibit hepatic glucose and delay gastric emptying1%Cardiac (IHD) and renal protectiveGI symptomsOnce a week or daily formulations
Start with lowest dose possible and titrate up.
May cause weight loss
Avoid if there is history of pancreatitis or medullary thyroid carcinoma or MEN.
SGLT-2iPrevent glucose reabsorption in the nephron and increase glucose excretion in the urine by inhibiting the SGLT-2 protein1%HF and renal protection
Low risk of hypoglycemia
Can be used in diabetes of any duration
Dehydration
GU infections
DKA
Recommended for patients with diabetes and HF and/or renal disease
Monitor for cystitis and yeast infections.
Keep up with oral hydration to volume depletion
Avoid in patients with T1DM.
  • BG, blood glucose; CKD, chronic kidney disease; DKA, diabetic ketoacidosis; DPP-4, dipeptidyl peptidase-4; GI, gastrointestinal; GLP-1, glucagon-like peptide-1; HbA1c, glycated hemoglobin; HF, heart failure; IHD, ischemic heart disease; MEN, multiple endocrine neoplasia; PPARγ, peroxisome proliferator-activated receptor; SGLT-2i, sodium–glucose cotransport 2 inhibitor; SU, sulfonylurea; T1DM, type 1 diabetes mellitus.