Prescribing metformin without indication is an example of irrational practice in diabetes management because it exposes patients to unnecessary medication risks without clinical benefit. Metformin should be used only when there is a clear diagnosis of diabetes or prediabetes with appropriate indications. Unnecessary use can lead to adverse effects like lactic acidosis, gastrointestinal symptoms, and increased healthcare costs. Rational prescribing ensures medication is tailored to the patient’s condition, improving safety and efficacy. In contrast, monitoring blood glucose, dietary counseling, and exercise advice are standard, evidence-based practices essential for optimal diabetes control.

Reference: Davidson’s Principles and Practice of Medicine, Kumar & Clark, 23rd Edition.