Question
During routine medical check-up a 50-year male office executive with sedentary lifestyle was diagnosed to have developed type 2 diabetes mellitus. His fasting and post-meal blood glucose was 130 mg/dl and 190 mg/dl respectively, HbA1C was 7.8%, BP was 130/82 mm Hg and body mass index was 24 kg/m2. He was asymptomatic and investigations revealed no end organ damage. He was advised suitable diet, exercise and other lifestyle modifications.
- (a) Classify drugs used in type 2 diabetes mellitus giving suitable examples. 5 mark(s)
- (b) Which antidiabetic will you prescribe in this patient. Explain the pharmacological basis for the selection. Write the mechanism of action and adverse effects of the same. 5 mark(s)
Answer
a) Classification of drugs for type 2 diabetes
| Class | Examples |
|---|---|
| Biguanides | Metformin |
| Sulfonylureas | Glibenclamide, Glimepiride |
| Thiazolidinediones | Pioglitazone |
| Alpha-glucosidase inhibitors | Acarbose |
| DPP-4 inhibitors | Sitagliptin |
| SGLT2 inhibitors | Dapagliflozin |
b) Antidiabetic selection, pharmacological basis, mechanism, adverse effects Metformin is the appropriate choice — this patient is newly diagnosed, asymptomatic, with no end-organ damage and a BMI in the overweight-but-not-obese range; metformin is first-line across essentially all major guidelines for exactly this profile.
Pharmacological basis: metformin activates AMPK, suppressing hepatic gluconeogenesis without stimulating insulin release, so it carries essentially no hypoglycemia risk as monotherapy — an important consideration for an asymptomatic, otherwise well patient starting therapy for the first time. It also has favorable effects on weight (weight-neutral to modest weight loss) compared to sulfonylureas, suiting a sedentary patient where weight gain would be counterproductive.
Mechanism: activates AMP-activated protein kinase (AMPK) in hepatocytes, suppressing hepatic gluconeogenesis and modestly increasing peripheral insulin sensitivity/glucose uptake.
Adverse effects: GI upset (nausea, diarrhea), lactic acidosis (rare but serious, risk amplified by renal impairment).