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Marcus Maurer - One of the best experts on this subject based on the ideXlab platform.
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comparison of the efficacy of levocetirizine 5 mg and Desloratadine 5 mg in chronic idiopathic urticaria patients
Allergy, 2009Co-Authors: P C Potter, Marcus Maurer, A Kapp, G Guillet, A M Jian, P Hauptmann, A Y FinlayAbstract:Background: Nonsedating H1-antihistamines are recommended for the treatment of urticaria by the recent EAACI/GA2LEN/EDF guidelines. The aim of this study was to compare the efficacy, after 4 weeks of treatment, with levocetirizine 5 mg and Desloratadine 5 mg, both once daily in the morning, in symptomatic chronic idiopathic urticaria (CIU) patients. Methods: This multi-center, randomized, double-blind study involved 886 patients (438 on levocetirizine and 448 on Desloratadine). The primary objective was to compare their efficacy on the mean pruritus severity score after 1 week of treatment. Mean pruritus severity score over 4 weeks and pruritus duration score, number and size of wheals, mean CIU composite score (sum of the scores for pruritus severity and numbers of wheals), quality of life, and the patient’s and investigator’s global satisfaction with treatment, were secondary efficacy measures. Results: Levocetirizine led to a significantly greater decrease in pruritus severity than Desloratadine over the first treatment week; mean pruritus severity scores of 1.02 and 1.18 for levocetirizine and Desloratadine, respectively (P < 0.001). The result was similar for the entire 4-week treatment period (P = 0.004). In addition, levocetirizine decreased pruritus duration and the mean CIU composite scores to a significantly greater extent than Desloratadine during the first week (P = 0.002 and 0.005, respectively) and over the entire study (P = 0.009 and P < 0.05, respectively). Similarly, levocetirizine increased the patients’ global satisfaction after one and 4 weeks (P = 0.012 and 0.021, respectively), compared with Desloratadine. Safety and tolerability were similar in both groups. Conclusions: Levocetirizine 5 mg was significantly more efficacious than Desloratadine 5 mg in the treatment of CIU symptoms.
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high dose Desloratadine decreases wheal volume and improves cold provocation thresholds compared with standard dose treatment in patients with acquired cold urticaria a randomized placebo controlled crossover study
The Journal of Allergy and Clinical Immunology, 2009Co-Authors: Frank Siebenhaar, Franziska Degener, Torsten Zuberbier, Peter Martus, Marcus MaurerAbstract:BACKGROUND: Increased dosing of nonsedating antihistamines is recommended by the current European Academy of Allergology and Clinical Immunology/Global Allergy and Asthma European Network/European Dermatology Forum guidelines on patients with acquired cold urticaria (ACU) who do not respond satisfactorily to the standard dose. Prospective data supporting this recommendation are scant. OBJECTIVE: We sought to assess the effects of 5 and 20 mg of Desloratadine and placebo on cold-induced urticarial reactions in patients with ACU. METHODS: In this prospective, randomized, double-blind, 3-way crossover trial, patients with ACU (n = 30) received placebo, 5 mg of Desloratadine, and 20 mg of Desloratadine every day each for 7 days separated by 14-day washout periods. At the end of each treatment, patients underwent cold provocation with the TempTest 2.0/2.1 system, and urticarial reactions were assessed by using digital 3-dimensional time-lapse photography and thermography; the critical temperature threshold (CTT) and critical stimulation time threshold (CSTT) were measured. Adverse events (AEs) reported during the study were assessed. RESULTS: Compared with placebo, 7 days of Desloratadine at 5 and 20 mg/d significantly reduced the volume of cold-induced wheals and areas of hyperthermic skin and improved CTT and CSTT results. Desloratadine at 20 mg/d significantly reduced cold-induced wheal volume and CTT and CSTT values versus Desloratadine at 5 mg/d. Desloratadine was well tolerated, with no increased rate of somnolence or other AEs with 20 mg of Desloratadine. CONCLUSIONS: Desloratadine at standard and high doses significantly improved objective signs of ACU provoked by cold exposure. Desloratadine at 4 times the standard dose significantly reduced ACU lesion severity versus 5 mg of Desloratadine without an increase in AEs. This study supports current guidelines that increased Desloratadine dosing might benefit patients with urticaria who do not respond to standard doses.
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High-dose Desloratadine decreases wheal volume and improves cold provocation thresholds compared with standard-dose treatment in patients with acquired cold urticaria: A randomized, placebo-controlled, crossover study
Journal of Allergy and Clinical Immunology, 2009Co-Authors: Frank Siebenhaar, Franziska Degener, Torsten Zuberbier, Peter Martus, Marcus MaurerAbstract:Background: Increased dosing of nonsedating antihistamines is recommended by the current European Academy of Allergology and Clinical Immunology/Global Allergy and Asthma European Network/European Dermatology Forum guidelines on patients with acquired cold urticaria (ACU) who do not respond satisfactorily to the standard dose. Prospective data supporting this recommendation are scant. Objective: We sought to assess the effects of 5 and 20 mg of Desloratadine and placebo on cold-induced urticarial reactions in patients with ACU. Methods: In this prospective, randomized, double-blind, 3-way crossover trial, patients with ACU (n = 30) received placebo, 5 mg of Desloratadine, and 20 mg of Desloratadine every day each for 7 days separated by 14-day washout periods. At the end of each treatment, patients underwent cold provocation with the TempTest 2.0/2.1 system, and urticarial reactions were assessed by using digital 3-dimensional time-lapse photography and thermography; the critical temperature threshold (CTT) and critical stimulation time threshold (CSTT) were measured. Adverse events (AEs) reported during the study were assessed. Results: Compared with placebo, 7 days of Desloratadine at 5 and 20 mg/d significantly reduced the volume of cold-induced wheals and areas of hyperthermic skin and improved CTT and CSTT results. Desloratadine at 20 mg/d significantly reduced cold-induced wheal volume and CTT and CSTT values versus Desloratadine at 5 mg/d. Desloratadine was well tolerated, with no increased rate of somnolence or other AEs with 20 mg of Desloratadine. Conclusions: Desloratadine at standard and high doses significantly improved objective signs of ACU provoked by cold exposure. Desloratadine at 4 times the standard dose significantly reduced ACU lesion severity versus 5 mg of Desloratadine without an increase in AEs. This study supports current guidelines that increased Desloratadine dosing might benefit patients with urticaria who do not respond to standard doses. © 2009 American Academy of Allergy, Asthma & Immunology.
Andrew Parkinson - One of the best experts on this subject based on the ideXlab platform.
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further characterization of the metabolism of Desloratadine and its cytochrome p450 and udp glucuronosyltransferase inhibition potential identification of Desloratadine as a relatively selective ugt2b10 inhibitor
Drug Metabolism and Disposition, 2015Co-Authors: Faraz Kazmi, Phyllis Yerino, Joanna E Barbara, Andrew ParkinsonAbstract:Desloratadine (Clarinex), the major active metabolite of loratadine (Claritin), is a nonsedating antihistamine used for the treatment of seasonal allergies and hives. Previously we reported that the formation of 3-hydroxyDesloratadine, the major human metabolite of Desloratadine, involves three sequential reactions, namely N -glucuronidation by UGT2B10 followed by 3-hydroxylation by CYP2C8 followed by deconjugation (rapid, nonenzymatic hydrolysis of the N -glucuronide). In this study we assessed the perpetrator potential of Desloratadine based on in vitro studies of its inhibitory effects on cytochrome P450 and UDP-glucuronosyltransferase (UGT) enzymes in human liver microsomes (HLM). Desloratadine (10 µ M) caused no inhibition (<15%) of CYP1A2, CYP2C8, CYP2C9, or CYP2C19 and weak inhibition (32–48%) of CYP2B6, CYP2D6, and CYP3A4/5. In cryopreserved human hepatocytes (CHH), which can form the CYP2C8 substrate Desloratadine N -glucuronide, Desloratadine did not inhibit the CYP2C8-dependent metabolism of paclitaxel or amodiaquine. Assessment of UGT inhibition identified Desloratadine as a potent and relatively selective competitive inhibitor of UGT2B10 ( K i value of 1.3 μ M). Chemical inhibition of UGT enzymes in HLM demonstrated that nicotine (UGT2B10 inhibitor) but not hecogenin (UGT1A4 inhibitor) completely inhibited the conversion of Desloratadine (1 µ M) to 3-hydroxyDesloratadine in HLM fortified with both NADPH and UDP-glucuronic acid. 3-HydroxyDesloratadine formation correlated well with levomedetomidine glucuronidation (UGT2B10 marker activity) with a panel of individual CHH ( r 2 = 0.72). Overall, the results of this study confirm the role of UGT2B10 in 3-hydroxyDesloratadine formation and identify Desloratadine as a relatively selective in vitro inhibitor of UGT2B10.
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Further Characterization of the Metabolism of Desloratadine and Its Cytochrome P450 and UDP-glucuronosyltransferase Inhibition Potential: Identification of Desloratadine as a Relatively Selective UGT2B10 Inhibitor
Drug Metabolism and Disposition, 2015Co-Authors: Faraz Kazmi, Phyllis Yerino, Joanna E Barbara, Andrew ParkinsonAbstract:Desloratadine (Clarinex), the major active metabolite of loratadine (Claritin), is a nonsedating antihistamine used for the treatment of seasonal allergies and hives. Previously we reported that the formation of 3-hydroxyDesloratadine, the major human metabolite of Desloratadine, involves three sequential reactions, namely N -glucuronidation by UGT2B10 followed by 3-hydroxylation by CYP2C8 followed by deconjugation (rapid, nonenzymatic hydrolysis of the N -glucuronide). In this study we assessed the perpetrator potential of Desloratadine based on in vitro studies of its inhibitory effects on cytochrome P450 and UDP-glucuronosyltransferase (UGT) enzymes in human liver microsomes (HLM). Desloratadine (10 µ M) caused no inhibition (
Eli O Meltzer - One of the best experts on this subject based on the ideXlab platform.
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efficacy of fexofenadine versus Desloratadine in suppressing histamine induced wheal and flare
Allergy and Asthma Proceedings, 2007Co-Authors: Eli O Meltzer, Sherwin A GillmanAbstract:To date, no published articles exist comparing the H 1 -receptor antagonist activities of fexofenadine and Desloratadine using the histamine-induced skin wheal-and-flare model. The aim of this study was to compare the efficacy of fexofenadine versus Desloratadine in suppressing histamine-induced skin flares and wheals in adults and adolescents. This was a two-center, randomized, placebo-controlled, complete-crossover study. Subjects were administered either single-dose fexofenadine HCl, 180 mg; Desloratadine, 5 mg; or placebo and their response to skin-prick testing with histamine and diluent was recorded at predetermined time intervals. The primary end point was change in size of histamine-induced summation skin flares. Secondary end points included change in skin wheal summation measurements, onset, duration, maximum percent suppression, and time to maximum suppression of flares and wheals. Fexofenadine suppressed skin flares significantly more than Desloratadine from 2 to 6 hours, and wheals from 2 to 4 hours, 6 to 9 hours, and 12 hours posttreatment. In addition, fexofenadine suppressed flares more than placebo at all time points from 2 to 24 hours and wheals more than placebo at all time points from 2 to 12 hours posttreatment. Desloratadine suppressed flares significantly more than placebo from 6 to 10 hours and at 12 and 24 hours but suppressed wheals significantly versus placebo only at 10 hours. Fexofenadine had a faster onset of flare suppression than Desloratadine (1 hour versus 5 hours) and an equally rapid onset of wheal suppression. Fexofenadine HCl, 180 mg, was superior to Desloratadine, 5 mg, in histamine-induced wheal-and-flare suppression, suggesting increased in vivo H 1 -receptor antagonist potency of fexofenadine versus Desloratadine.
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effect of Desloratadine therapy on symptom scores and measures of nasal patency in seasonal allergic rhinitis results of a single center placebo controlled trial
Annals of Allergy Asthma & Immunology, 2006Co-Authors: Eli O Meltzer, Alfredo A Jalowayski, Klaus Vogt, Domenic G Iezzoni, Alan G HarrisAbstract:Background Desloratadine reduces symptoms and maintains nasal airflow in patients with seasonal allergic rhinitis (SAR) during experimental allergen exposure. Objective To compare the effects of Desloratadine and placebo on symptom scores, quality of life (QOL), and nasal airway patency in patients with SAR during the allergy season. Methods Adults with symptomatic SAR were randomized in a double-blind manner to receive Desloratadine, 5 mg, or placebo for 14 days. Patient-rated SAR symptoms were recorded twice daily (morning and evening). On days 1 and 15, SAR symptoms were scored jointly (investigator and patient), nasal airflow was measured using 4-phase rhinomanometry, and QOL and the overall condition of SAR were rated. Overall treatment response was scored on day 15. Adverse events were recorded. Results At day 15, total symptom ( P = .03) and total nasal symptom ( P = .02) scores and patient morning-rated individual nasal symptom scores (except nasal stuffiness) ( P ≤ .04) decreased significantly from baseline with Desloratadine vs placebo. Flow in the descending expiratory nasal airflow phase was significantly greater ( P = .046) and the percentage increase in total inspiratory nasal airway resistance was less ( P = .03) in the Desloratadine group vs the placebo group. The overall condition of SAR was less severe ( P = .045), the therapeutic response was greater ( P = .004), and the nasal symptom domain of the QOL score was significantly better ( P = .03) in the Desloratadine group. Adverse event rates were similar in both groups. Conclusion Desloratadine treatment for 14 days improved nasal airflow and resistance as well as symptom and QOL scores in patients with symptomatic SAR during the allergy season.
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Desloratadine a new nonsedating oral antihistamine
The Journal of Allergy and Clinical Immunology, 2001Co-Authors: Raif S Geha, Eli O MeltzerAbstract:Abstract Desloratadine is a new, selective, H 1 -receptor antagonist that also has anti-inflammatory activity. In vitro studies have shown that Desloratadine inhibits the release or generation of multiple inflammatory mediators, including IL-4, IL-6, IL-8, IL-13, PGD 2 , leukotriene C 4 , tryptase, histamine, and the TNF-α–induced chemokine RANTES. Desloratadine also inhibits the induction of cell adhesion molecules, plateletactivating factor–induced eosinophil chemotaxis, TNF-α–induced eosinophil adhesion, and spontaneous and phorbol myristate acetate–induced superoxide generation in vitro. In animals Desloratadine had no effect on the central nervous, cardiovascular, renal, or gastrointestinal systems. Desloratadine is rapidly absorbed, has dose-proportional pharmacokinetics, and has a half-life of 27 hours. The absorption of Desloratadine is not affected by food, and the metabolism and elimination are not significantly affected by the subject's age, race, or sex. There are no clinically relevant interactions between Desloratadine and erythromycin, ketoconazole, or grapefruit juice. Desloratadine is not a significant substrate of the P-glycoprotein transport system. Once daily administration of Desloratadine rapidly reduces the nasal and nonnasal symptoms of seasonal allergic rhinitis, including congestion. In patients with seasonal allergic rhinitis and concomitant asthma, Desloratadine treatment was also associated with significant reductions in total asthma symptom score and use of inhaled β 2 -agonists. Use of Desloratadine in patients with chronic idiopathic urticaria was associated with significant reductions in pruritus, number of hives, size of the largest hive, and interference with sleep and daily activities. Clinical experience in over 2300 patients has shown that the adverse event profile of Desloratadine is similar to that of placebo; Desloratadine has no clinically relevant effects on electrocardiographic parameters, does not impair wakefulness or psychomotor performance, and does not exacerbate the psychomotor impairment associated with alcohol use. (J Allergy Clin Immunol 2001;107:751-62.)
Torsten Zuberbier - One of the best experts on this subject based on the ideXlab platform.
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randomized controlled trial of Desloratadine for persistent allergic rhinitis correlations between symptom improvement and quality of life
Allergy and Asthma Proceedings, 2013Co-Authors: Jean Bousquet, Torsten Zuberbier, Walter G Canonica, Wytske J Fokkens, Gokul Gopalan, Tulin ShekarAbstract:Allergic rhinitis (AR) symptoms can impart emotional, quality of life (QOL), and work productivity burdens, especially in persistent AR (PER). Desloratadine, an H1-receptor antagonist, has been shown to be effective against nasal and nonnasal AR symptoms and to improve QOL. Exploratory analyses were conducted to evaluate whether Desloratadine-mediated symptom improvement correlated with improvements in QOL and productivity. The Aerius Control: Clinical and Evaluative Profile of Treatment 2 (NCT00405964) study was a 12-week, multinational, randomized, placebo-controlled prospective study of once-daily Desloratadine at 5 mg in subjects with moderate-to-severe PER. Assessments included twice-daily symptom severity ratings (0 = none to 3 = severe; total and individual symptoms), sleep interference (morning [A.M.]), interference with activities of daily living (ADL; evening [P.M.]), the Rhinoconjunctivitis Quality of Life Questionnaire-Standardized version (baseline and days 29 and 85), and the Work Productivity and Activity Impairment-Allergy-Specific questionnaire (baseline and weekly). Pearson product-moment correlation statistics (r) were determined to assess correlations between symptom score improvements and QOL factors. All Desloratadine-treated patients (n = 360) were included in this exploratory analysis. In the Desloratadine-treated patients, all correlations tested were positive (all p < 0.0001). The highest coefficients were seen for the correlations between A.M./P.M. PRIOR total five-symptom score and interference with ADL (r = 0.72) and between A.M. NOW congestion and ADL interference (r = 0.69). Continuous daily treatment of moderate-to-severe PER with Desloratadine at 5 mg/day significantly improved symptoms, which correlated positively, albeit moderately, with QOL benefits and reversal of functional impairments caused by PER
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high dose Desloratadine decreases wheal volume and improves cold provocation thresholds compared with standard dose treatment in patients with acquired cold urticaria a randomized placebo controlled crossover study
The Journal of Allergy and Clinical Immunology, 2009Co-Authors: Frank Siebenhaar, Franziska Degener, Torsten Zuberbier, Peter Martus, Marcus MaurerAbstract:BACKGROUND: Increased dosing of nonsedating antihistamines is recommended by the current European Academy of Allergology and Clinical Immunology/Global Allergy and Asthma European Network/European Dermatology Forum guidelines on patients with acquired cold urticaria (ACU) who do not respond satisfactorily to the standard dose. Prospective data supporting this recommendation are scant. OBJECTIVE: We sought to assess the effects of 5 and 20 mg of Desloratadine and placebo on cold-induced urticarial reactions in patients with ACU. METHODS: In this prospective, randomized, double-blind, 3-way crossover trial, patients with ACU (n = 30) received placebo, 5 mg of Desloratadine, and 20 mg of Desloratadine every day each for 7 days separated by 14-day washout periods. At the end of each treatment, patients underwent cold provocation with the TempTest 2.0/2.1 system, and urticarial reactions were assessed by using digital 3-dimensional time-lapse photography and thermography; the critical temperature threshold (CTT) and critical stimulation time threshold (CSTT) were measured. Adverse events (AEs) reported during the study were assessed. RESULTS: Compared with placebo, 7 days of Desloratadine at 5 and 20 mg/d significantly reduced the volume of cold-induced wheals and areas of hyperthermic skin and improved CTT and CSTT results. Desloratadine at 20 mg/d significantly reduced cold-induced wheal volume and CTT and CSTT values versus Desloratadine at 5 mg/d. Desloratadine was well tolerated, with no increased rate of somnolence or other AEs with 20 mg of Desloratadine. CONCLUSIONS: Desloratadine at standard and high doses significantly improved objective signs of ACU provoked by cold exposure. Desloratadine at 4 times the standard dose significantly reduced ACU lesion severity versus 5 mg of Desloratadine without an increase in AEs. This study supports current guidelines that increased Desloratadine dosing might benefit patients with urticaria who do not respond to standard doses.
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High-dose Desloratadine decreases wheal volume and improves cold provocation thresholds compared with standard-dose treatment in patients with acquired cold urticaria: A randomized, placebo-controlled, crossover study
Journal of Allergy and Clinical Immunology, 2009Co-Authors: Frank Siebenhaar, Franziska Degener, Torsten Zuberbier, Peter Martus, Marcus MaurerAbstract:Background: Increased dosing of nonsedating antihistamines is recommended by the current European Academy of Allergology and Clinical Immunology/Global Allergy and Asthma European Network/European Dermatology Forum guidelines on patients with acquired cold urticaria (ACU) who do not respond satisfactorily to the standard dose. Prospective data supporting this recommendation are scant. Objective: We sought to assess the effects of 5 and 20 mg of Desloratadine and placebo on cold-induced urticarial reactions in patients with ACU. Methods: In this prospective, randomized, double-blind, 3-way crossover trial, patients with ACU (n = 30) received placebo, 5 mg of Desloratadine, and 20 mg of Desloratadine every day each for 7 days separated by 14-day washout periods. At the end of each treatment, patients underwent cold provocation with the TempTest 2.0/2.1 system, and urticarial reactions were assessed by using digital 3-dimensional time-lapse photography and thermography; the critical temperature threshold (CTT) and critical stimulation time threshold (CSTT) were measured. Adverse events (AEs) reported during the study were assessed. Results: Compared with placebo, 7 days of Desloratadine at 5 and 20 mg/d significantly reduced the volume of cold-induced wheals and areas of hyperthermic skin and improved CTT and CSTT results. Desloratadine at 20 mg/d significantly reduced cold-induced wheal volume and CTT and CSTT values versus Desloratadine at 5 mg/d. Desloratadine was well tolerated, with no increased rate of somnolence or other AEs with 20 mg of Desloratadine. Conclusions: Desloratadine at standard and high doses significantly improved objective signs of ACU provoked by cold exposure. Desloratadine at 4 times the standard dose significantly reduced ACU lesion severity versus 5 mg of Desloratadine without an increase in AEs. This study supports current guidelines that increased Desloratadine dosing might benefit patients with urticaria who do not respond to standard doses. © 2009 American Academy of Allergy, Asthma & Immunology.
Frank Siebenhaar - One of the best experts on this subject based on the ideXlab platform.
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high dose Desloratadine decreases wheal volume and improves cold provocation thresholds compared with standard dose treatment in patients with acquired cold urticaria a randomized placebo controlled crossover study
The Journal of Allergy and Clinical Immunology, 2009Co-Authors: Frank Siebenhaar, Franziska Degener, Torsten Zuberbier, Peter Martus, Marcus MaurerAbstract:BACKGROUND: Increased dosing of nonsedating antihistamines is recommended by the current European Academy of Allergology and Clinical Immunology/Global Allergy and Asthma European Network/European Dermatology Forum guidelines on patients with acquired cold urticaria (ACU) who do not respond satisfactorily to the standard dose. Prospective data supporting this recommendation are scant. OBJECTIVE: We sought to assess the effects of 5 and 20 mg of Desloratadine and placebo on cold-induced urticarial reactions in patients with ACU. METHODS: In this prospective, randomized, double-blind, 3-way crossover trial, patients with ACU (n = 30) received placebo, 5 mg of Desloratadine, and 20 mg of Desloratadine every day each for 7 days separated by 14-day washout periods. At the end of each treatment, patients underwent cold provocation with the TempTest 2.0/2.1 system, and urticarial reactions were assessed by using digital 3-dimensional time-lapse photography and thermography; the critical temperature threshold (CTT) and critical stimulation time threshold (CSTT) were measured. Adverse events (AEs) reported during the study were assessed. RESULTS: Compared with placebo, 7 days of Desloratadine at 5 and 20 mg/d significantly reduced the volume of cold-induced wheals and areas of hyperthermic skin and improved CTT and CSTT results. Desloratadine at 20 mg/d significantly reduced cold-induced wheal volume and CTT and CSTT values versus Desloratadine at 5 mg/d. Desloratadine was well tolerated, with no increased rate of somnolence or other AEs with 20 mg of Desloratadine. CONCLUSIONS: Desloratadine at standard and high doses significantly improved objective signs of ACU provoked by cold exposure. Desloratadine at 4 times the standard dose significantly reduced ACU lesion severity versus 5 mg of Desloratadine without an increase in AEs. This study supports current guidelines that increased Desloratadine dosing might benefit patients with urticaria who do not respond to standard doses.
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High-dose Desloratadine decreases wheal volume and improves cold provocation thresholds compared with standard-dose treatment in patients with acquired cold urticaria: A randomized, placebo-controlled, crossover study
Journal of Allergy and Clinical Immunology, 2009Co-Authors: Frank Siebenhaar, Franziska Degener, Torsten Zuberbier, Peter Martus, Marcus MaurerAbstract:Background: Increased dosing of nonsedating antihistamines is recommended by the current European Academy of Allergology and Clinical Immunology/Global Allergy and Asthma European Network/European Dermatology Forum guidelines on patients with acquired cold urticaria (ACU) who do not respond satisfactorily to the standard dose. Prospective data supporting this recommendation are scant. Objective: We sought to assess the effects of 5 and 20 mg of Desloratadine and placebo on cold-induced urticarial reactions in patients with ACU. Methods: In this prospective, randomized, double-blind, 3-way crossover trial, patients with ACU (n = 30) received placebo, 5 mg of Desloratadine, and 20 mg of Desloratadine every day each for 7 days separated by 14-day washout periods. At the end of each treatment, patients underwent cold provocation with the TempTest 2.0/2.1 system, and urticarial reactions were assessed by using digital 3-dimensional time-lapse photography and thermography; the critical temperature threshold (CTT) and critical stimulation time threshold (CSTT) were measured. Adverse events (AEs) reported during the study were assessed. Results: Compared with placebo, 7 days of Desloratadine at 5 and 20 mg/d significantly reduced the volume of cold-induced wheals and areas of hyperthermic skin and improved CTT and CSTT results. Desloratadine at 20 mg/d significantly reduced cold-induced wheal volume and CTT and CSTT values versus Desloratadine at 5 mg/d. Desloratadine was well tolerated, with no increased rate of somnolence or other AEs with 20 mg of Desloratadine. Conclusions: Desloratadine at standard and high doses significantly improved objective signs of ACU provoked by cold exposure. Desloratadine at 4 times the standard dose significantly reduced ACU lesion severity versus 5 mg of Desloratadine without an increase in AEs. This study supports current guidelines that increased Desloratadine dosing might benefit patients with urticaria who do not respond to standard doses. © 2009 American Academy of Allergy, Asthma & Immunology.