Cost-effectiveness of antihistaminics in adults' patients with allergic rhinitis.

INTRODUCTION: Allergic rhinitis (AR) is highly prevalent worldwide, often leading to substantial healthcare costs and diminished patient quality of life. Although guidelines frequently recommend intranasal corticosteroids, oral second-generation antihistamines remain commonly used in many low- and middle-income countries. We performed a cost-utility analysis of newer-generation oral H1 antihistamines for adults with intermittent AR in Colombia. MATERIALS AND METHODS: A 28-day decision-tree model compared multiple antihistamines' costs and quality-adjusted life years (QALYs). Inputs included clinical effectiveness and adverse-event probabilities from systematic reviews and network meta-analyses. All costs, expressed in 2024 US dollars (1 USD = 4,400 COP), were adjusted for inflation. Net monetary benefits (NMB) were calculated using willingness-to-pay thresholds for Colombia (US$ 5130). Probabilistic sensitivity analyses were conducted to assess uncertainty in key parameters. RESULTS: Cetirizine 10 mg and fexofenadine 180 mg were the only undominated strategies, exhibiting higher NMB values than other antihistamines. Deterministic analysis showed that cetirizine had a lower total cost (22.15 USD) and an ICER of 349.62 USD per QALY gained. In contrast, fexofenadine provided a slight gain in effectiveness at a modest incremental cost. Probabilistic analysis confirmed fexofenadine as cost-effective option across a wide range of thresholds, with cetirizine remaining a strong contender at lower thresholds. CONCLUSION: In this cost-utility analysis of oral H1 antihistamines for adults with intermittent allergic rhinitis in Colombia, cetirizine 10 mg and fexofenadine 180 mg emerged as the cost-effective options, offering high net monetary benefits and remaining undominated in deterministic and probabilistic analyses.