A Double-Blind, Randomized Controlled Trial Comparing the Clinical Efficacy and Safety of Prasaprohyai Extract Capsules and Loratadine in Patients with Allergic Rhinitis
Adisak Sumalee¹, Waipoj Chanvimalueng², Arunporn Itharat³,⁴, Nichamon Mukkasombut³,⁴, Sunita Makchuchit, PhD⁴, Pranporn Kuropakornpong, PhD⁴, Reawfang Sriyom, B.ATM³, Neal M Davies, PhD⁵
Affiliation : ¹ PhD Student in Applied Thai Traditional Medicine, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand; ² Department of Otolaryngology, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand; ³ Department of Applied Thai Traditional Medicine, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand; ⁴ Center of Excellence in Applied Thai Traditional Medicine Research (CEATMR), Faculty of Medicine, Thammasat University, Pathum Thani, Thailand; ⁵ Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
Background: Prasaprohyai (PSP) is a traditional Thai remedy used to treat fever associated with cold symptoms, as listed in the National List of Essential Medicines of Thailand. Its ethanolic extract has been reported to have antiallergic effects in animal models.
Objective: To investigate the clinical efficacy and safety of PSP ethanolic extract in allergic rhinitis (AR) patients compared with loratadine.
Materials and Methods: A double-blind, randomized controlled trial comparison was used. The participants, including 162 patients with AR, were randomly divided into two groups using a pre-generated random assignment scheme enclosed in envelopes with 81 patients who were treated with 10 mg/day of loratadine, and 81 patients were treated with 300 mg/day of PSP capsule for six weeks. Efficacy was assessed through the level of nasal symptoms and the narrowest cross-sectional area (CSA) of the nasal cavity using acoustic rhinometry. In addition, safety was evaluated through blood biochemical tests conducted at weeks 0, 3, and 6.
Results: The results demonstrated that patients who received either the PSP ethanolic extract capsule or loratadine for six weeks showed continuous improvement in total nasal symptoms, including runny nose, nasal congestion, itchy nose, sneezing, and nasal cavity function. No significant differences were observed between the two groups. Additionally, blood biochemistry results for both groups remained within normal ranges, with no significant differences between them.
Conclusion: Both the PSP ethanolic extract capsule and loratadine were effective in the treatment of AR and showed no adverse events or safety concerns over the six-week administration period.
Trial registration: Thai Clinical Trials Registry, TCTR20231025003
Received 13 May 2025 | Revised 11 September 2025 | Accepted 25 September 2025
DOI: 10.35755/jmedassocthai.2025.10.808-816-02984
Keywords : Prasaprohyai extract; Allergic rhinitis; Clinical trial; Loratadine
