Efficacy of diphenhydramine vs desloratadine and placebo in patients with moderate-to-severe seasonal allergic rhinitis

Ann Allergy Asthma Immunol. 2006 Apr;96(4):606-14. doi: 10.1016/S1081-1206(10)63557-0.

Abstract

Background: Previous studies have shown that diphenhydramine and desloratadine effectively relieve symptoms of seasonal allergic rhinitis (SAR).

Objective: To compare the relative efficacy of 50 mg of diphenhydramine hydrochloride, 5 mg of desloratadine, and placebo in relieving symptoms in patients with moderate-to-severe SAR.

Methods: In this 1-week, multicenter, parallel-group, randomized, double-blind, double-dummy, placebo-controlled study, 610 patients with moderate-to-severe SAR received 50 mg of diphenhydramine hydrochloride 3 times daily, 5 mg of desloratadine once daily, or placebo. Daily 24-hour reflective total nasal symptom scores (TNSSs) (primary end point), total symptom scores, and individual symptom scores were evaluated. A global evaluation of response to treatment was conducted at 2 posttreatment visits.

Results: The mean reduction from baseline in 24-hour reflective TNSSs relative to the placebo response was 77.6% for the diphenhydramine group (P < .001) and 21.0% for the desloratadine group (P = .12). A TNSS between-treatment difference of -1.81 (46.7%; P < .001) was observed when comparing diphenhydramine with desloratadine. A similar between-treatment difference was observed for the 24-hour reflective total symptom score comparing diphenhydramine to desloratadine (-3.35; 45.5%; P < .001). Diphenhydramine provided clinically and statistically significant reductions vs placebo and desloratadine in all individual symptoms, including nasal congestion. Desloratadine had a tendency toward improvement compared with placebo for most individual symptom scores. However, a statistically significant result was reached only for sneezing (-0.27; 33.9%; P = .04).

Conclusions: Diphenhydramine, 50 mg, given for 1 week provided statistically significant and clinically superior improvements in symptoms compared with 5 mg of desloratadine in patients with moderate-to-severe SAR. Somnolence occurred more frequently with diphenhydramine (22.1%) compared with desloratadine (4.5%) and placebo (3.4%).

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Allergic Agents / adverse effects
  • Anti-Allergic Agents / therapeutic use
  • Child
  • Diphenhydramine / adverse effects
  • Diphenhydramine / therapeutic use*
  • Double-Blind Method
  • Female
  • Histamine H1 Antagonists / adverse effects
  • Histamine H1 Antagonists / therapeutic use
  • Histamine H1 Antagonists, Non-Sedating / adverse effects
  • Histamine H1 Antagonists, Non-Sedating / therapeutic use
  • Humans
  • Loratadine / adverse effects
  • Loratadine / analogs & derivatives*
  • Loratadine / therapeutic use
  • Male
  • Middle Aged
  • Nasal Decongestants / adverse effects
  • Nasal Decongestants / therapeutic use*
  • Nasal Obstruction
  • Rhinitis, Allergic, Seasonal / drug therapy*

Substances

  • Anti-Allergic Agents
  • Histamine H1 Antagonists
  • Histamine H1 Antagonists, Non-Sedating
  • Nasal Decongestants
  • Loratadine
  • Diphenhydramine
  • desloratadine