Impact of Anti-Allergic Drug Therapy on the Incidence of Diabetes Mellitus: A Narrative Review

Abstract

Background: Anti-allergic medications are widely used for allergic rhinitis, asthma, urticaria, atopic dermatitis, and other hypersensitivity-related disorders. Because many patients require repeated or long-term therapy, potential metabolic consequences are clinically important, particularly in individuals with obesity, prediabetes, established diabetes, advanced age, or polypharmacy. Corticosteroids are well recognized to disturb glucose regulation, whereas the metabolic implications of antihistamines, leukotriene receptor antagonists, and mast cell stabilizers remain less clearly synthesized. Objective: This narrative review aimed to synthesize current pharmacological, mechanistic, and clinical evidence on the relationship between major anti-allergic drug classes and the risk of hyperglycemia, insulin resistance, and diabetes mellitus. Methods: A narrative synthesis was conducted using biomedical and pharmacological literature related to anti-allergic drugs, glucose metabolism, drug-induced hyperglycemia, insulin resistance, and diabetes mellitus. Evidence was organized thematically by drug class, including systemic and inhaled corticosteroids, first- and second-generation antihistamines, leukotriene receptor antagonists, and mast cell stabilizers. Emphasis was placed on biological mechanisms, relative diabetogenic potential, patient-level susceptibility, and clinical implications for prescribing and monitoring. Results: Systemic corticosteroids showed the strongest association with dysglycemia through increased hepatic gluconeogenesis, reduced peripheral glucose uptake, insulin resistance, adipose tissue effects, and β-cell stress. Inhaled and intranasal corticosteroids appeared lower risk but may be relevant with high cumulative exposure. Antihistamines were generally low risk, with first-generation agents carrying possible indirect metabolic concern through sedation, reduced activity, appetite change, and weight gain. Leukotriene receptor antagonists and mast cell stabilizers appeared metabolically neutral in routine use. Conclusion: Anti-allergic therapy has drug-class–specific metabolic implications. Corticosteroid exposure requires the greatest caution, while non-corticosteroid agents are generally metabolically safer. Individualized prescribing, dose minimization, and targeted glucose monitoring are most important for patients with existing metabolic risk