Beyond Symptom Relief: Assessing Efficacy and Safety in Nasal Congestion Treatments

Nasal congestion is a common and often unpleasant sign of allergic rhinitis (AR), with implications ranging beyond the impression of a blocked nose to decreased sleep, impaired daytime functioning, and poor quality of life (1,2). Unlike sneezing, rhinorrhoea and nasal pruritus, which are predominantly histamine-mediated, congestion reflects vascular engorgement, increased nasal blood flow and mucosal oedema occurring within the broader inflammatory response. This distinction is of significant therapeutic importance.

Nasal Congestion May Require More Than an Oral Antihistamine

Oral H1-antihistamines effectively control several histamine-mediated AR symptoms, but their effect on nasal obstruction is relatively modest (1,3). Effective management of congestion therefore requires consideration of the underlying inflammation, the need for rapid symptom relief, and the efficacy and safety of different decongestant strategies.

Intranasal corticosteroids (INCS) are a mainstay of allergic rhinitis (AR) treatment. The 2023 International Consensus Statement supports INCS as first-line therapy, while the latest ARIA-EAACI recommendations favour INCS over oral antihistamines when choosing between these treatment classes (1–3).

This is particularly relevant in nasal congestion, where inflammation and mucosal oedema contribute substantially to obstruction. While oral antihistamines are effective for AR symptoms, INCS provide broader control of nasal symptoms, including congestion (1–3). In patients requiring more rapid relief of marked nasal obstruction, decongestants may have a short-term adjunctive role, provided their potential adverse effects and limitations with prolonged use are considered (1).

Challenges with Topical Nasal Decongestants

Topical sympathomimetic decongestants such as oxymetazoline and xylometazoline rapidly relieve nasal obstruction by producing vasoconstriction and reducing mucosal swelling (1,2). However, duration of use is an important safety consideration. Prolonged or repeated use has been associated with rebound congestion and rhinitis medicamentosa, although evidence regarding their development and underlying mechanisms remains conflicting (4).

Real-world data also highlight the potential for misuse. A 2023 community pharmacy-based survey found that sympathomimetic nasal medicines were reportedly used at higher-than-recommended doses in up to 44.4% of cases, while use exceeded five days in up to 31.9% (5). Current ARIA-EAACI guidance therefore suggests against long-term intranasal decongestant use and recommends restricting treatment to short-term relief; no longer than five days and preferably for a shorter duration (2).

Pseudoephedrine & Phenylephrine: How are they Different?

Clinical evidence suggests that oral phenylephrine and pseudoephedrine should not be considered equivalent in decongestant efficacy (6,7). In a randomised, placebo-controlled crossover study of 39 patients with seasonal allergic rhinitis, Horak et al. compared single doses of phenylephrine 12 mg, pseudoephedrine 60 mg and placebo. Phenylephrine did not significantly improve nasal congestion versus placebo (P=0.56), whereas pseudoephedrine produced significantly greater improvement than both placebo (P<0.01) and phenylephrine (P=0.01) (6).

Similar findings emerged from a randomised, double-blind, dose-ranging trial involving 539 adults with seasonal allergic rhinitis. After seven days of treatment, none of the evaluated phenylephrine doses (10, 20, 30 or 40 mg) significantly improved reflective nasal congestion scores compared with placebo (7). Collectively, these studies provide stronger clinical evidence supporting the decongestant efficacy of oral pseudoephedrine over oral phenylephrine at commonly evaluated doses (6,7).

Fexofenadine-Pseudoephedrine: Complementary Mechanisms, Faster Onset of Action & Broader Symptom Control

Combining fexofenadine with pseudoephedrine provides complementary symptom control in allergic rhinitis. Fexofenadine, a second-generation H1-antihistamine, targets primarily histamine-mediated symptoms, while pseudoephedrine acts as a sympathomimetic decongestant to reduce nasal obstruction (8).

In a multicentre, randomised, double-blind study of 651 patients with seasonal allergic rhinitis, Sussman et al. found that the fexofenadine-pseudoephedrine combination was significantly more effective than fexofenadine alone in reducing nasal congestion and more effective than pseudoephedrine alone in controlling primarily histamine-mediated symptoms. No serious adverse events or clinically significant changes in ECG parameters, vital signs or laboratory values were reported (8).

Rapid symptom relief has also been demonstrated under controlled allergen exposure. A pooled analysis of two randomised, double-blind, placebo-controlled studies, comprising 784 participants in the modified intention-to-treat analysis, showed that the fixed-dose combination of fexofenadine hydrochloride 60 mg and pseudoephedrine hydrochloride 120 mg had an onset of action at 45 minutes, with the treatment effect sustained throughout the six-hour assessment period (9).

Objective evidence from a randomised trial of 24 adults with perennial allergic rhinitis and nasal obstruction further substantiates the clinical benefit. Compared with fexofenadine alone, fexofenadine pseudoephedrine combination significantly improved nasal airflow, with onset of action at 30 minutes by rhinomanometry and subjective improvement in nasal obstruction from 60 minutes reported with a visual analogue scale (10).

Figure: Relieving Nasal Congestion in Allergic Rhinitis: Treatment Overview

Pseudoephedrine: Balancing Decongestant Efficacy with Safety

The efficacy of pseudoephedrine must be balanced against its systemic sympathomimetic effects. A meta-analysis of 24 randomised placebo-controlled trials involving 1,285 adults found small but significant mean increases in systolic blood pressure (0.99 mmHg) and heart rate (2.83 beats/min), with no significant effect on diastolic blood pressure. Higher doses and immediate-release formulations were associated with greater blood pressure increases (11). Although the average changes were modest, individual risk remains important. ICAR 2023 recommends pseudoephedrine only as short-term/rescue therapy, with consideration of risks and benefits, comorbidities and alternative intranasal treatments (1).

Key Takeaways

• Comprehensive symptom management is important in allergic rhinitis: Effective treatment should address both histamine-mediated symptoms, such as sneezing, rhinorrhoea, and itching, as well as nasal congestion.
• Pseudoephedrine provides effective decongestion: Among oral decongestants, pseudoephedrine has demonstrated efficacy in relieving nasal congestion. When used appropriately at recommended doses, its benefits should be considered alongside individual risks, contraindications, and comorbidities.
• Fexofenadine–pseudoephedrine offers rapid, broad symptom relief: By combining antihistaminic and decongestant actions, fexofenadine–pseudoephedrine addresses both histamine-mediated symptoms and nasal congestion, with clinical evidence demonstrating an onset of action as early as 30 minutes, supporting its use when rapid, comprehensive relief is required.

MAT-IN-2601196-v1.0-23/09/2026

For the use only of a Registered Medical Practitioner or a hospital or a laboratory.