The goal of this clinical trial is to learn whether a higher dose of cetirizine works better than the standard dose to relieve symptoms of acute urticaria (hives) in adults. The study also aims to learn about the safety of taking a higher dose for a short period of time. The main questions the study aims to answer are: Does the higher dose of cetirizine help people with acute urticaria improve faster than the standard dose? What side effects do participants experience when taking the higher dose? Researchers will compare two groups: one group taking the standard dose of cetirizine (10 mg per day) and another group taking a higher dose (40 mg per day). This will help researchers understand which dose works better and whether the higher dose is safe. Participants will: Take the assigned study medication for 7 days Record their daily symptoms, including itch and hive severity Return for follow-up visits on Day 3, Day 7, and Week 6 Have blood tests to check liver and kidney function before and after treatment This study may help improve treatment options for people with acute urticaria and reduce the need for unnecessary steroid use.
This study is a randomized, parallel-group clinical trial designed to evaluate whether a higher dose of cetirizine provides better symptom relief than the standard dose in adults with acute urticaria. Acute urticaria often causes sudden wheals and intense itching that can significantly affect comfort and daily functioning. Although standard-dose second-generation antihistamines are recommended as first-line treatment, many people do not fully improve and are frequently prescribed systemic corticosteroids, which may lead to unnecessary side effects. This trial investigates whether increasing the dose of cetirizine to 40 mg per day offers faster or more complete symptom improvement without increasing safety risks. Participants will be randomly assigned to receive either the standard dose or the higher dose for 7 days. The study uses a blinded outcome assessment to minimize bias. Symptom severity will be measured using validated tools, and participants will be monitored for side effects throughout the study. Laboratory tests will be used to assess kidney and liver function before and after treatment. Follow-up visits will evaluate short-term changes in symptoms as well as the potential for recurrence or progression to chronic urticaria. The findings may help guide clinical decision-making and support more rational use of antihistamines while reducing reliance on corticosteroids in acute urticaria care.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
140
Participants in the standard-dose arm receive cetirizine 10 mg orally once daily for 7 days. The study medication is provided in capsule form to match the appearance of the high-dose capsules.
Participants in the high-dose arm receive cetirizine 20 mg orally twice daily (total 40 mg/day) for 7 days. The study medication is provided in capsule form to ensure identical appearance between arms.
University of Phayao Hospital
Phayao, Muang, Thailand
Time to Resolution of Acute Urticaria Symptoms
The time from the first dose of study medication to the complete resolution of acute urticaria symptoms, defined as the absence of hives and an itch score of 0 for at least 24 consecutive hours. Symptom status will be assessed using patient-reported daily symptom diaries and validated scoring tools.
Time frame: From Day 0 (first dose) to Day 7 or until complete symptom resolution, whichever occurs first.
Change in Urticaria Activity Score From Baseline
The change in total UAS7 score from baseline to Day 7, based on daily patient-reported wheal and itch scores collected in symptom diaries.
Time frame: Baseline to Day 7
Use of Systemic Corticosteroids as Rescue Medication
The proportion of participants requiring systemic corticosteroids due to persistent or worsening acute urticaria symptoms despite taking the assigned study medication.
Time frame: Day 0 to Day 7
Change in Dermatology Life Quality Index (DLQI)
The change in Dermatology Life Quality Index (DLQI) from baseline to Day 7 to assess the clinical response and quality of life impact of treatment.
Time frame: Baseline to Day 7
Incidence and Characteristics of Adverse Events
Number, type, and severity of adverse events occurring during treatment with standard-dose versus high-dose cetirizine. Adverse events may include sedation, dizziness, or other treatment-related symptoms.
Time frame: Day 0 to Day 7 and Week 6 follow-up
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