Ginger extract versus Loratadine in the treatment of allergic rhinitis: a randomized controlled trial

Background: Allergic rhinitis (AR) is a non-infectious immune disease and incidents of the disease has continuously increased in Thailand. Ginger, a Thai herb, is used in food and Thai traditional medicine. This study was designed to assess efficacy and safety of ginger extract in comparison with loratadine for AR treatment.

Methods: AR patients were treated with ginger extract 500 mg (n = 40) against those treated with loratadine 10 mg (n = 40) in a randomized, double-blind, controlled trial for 3 and 6 weeks. The efficacy was evaluated from clinical examinations i.e. total nasal symptom scores (TNSS), cross-sectional area of the nasal cavity with acoustic rhinometry (ARM) and rhinoconjunctivitis quality of life questionnaire (RQLQ). The safety of treatment was measured by blood pressure, blood analysis and history-taking for side effects.

Results: The results showed both ginger extract and loratadine treated groups significantly decreased TNSS scores but there was no significant difference between the two groups. In acoustic rhinometry measurement, the ginger treated group significantly gradually increased the estimated volume of the nasal cavity and decreased distances from the nostril, but the loratadine treated group did not cause a change. Both groups gave significantly improvement in every aspect of the RQLQ at third weeks. The treatment with ginger extract was as safe as loratadine as shown by renal and liver function results obtained from blood analysis. Both treatments had no effect on blood pressure of the patients.

Conclusions: The ginger extract is as good as loratadine in improving nasal symptoms and quality of life in AR patients. However, ginger extract caused less side effects especially, drowsiness, fatigue, dizziness and constipation. Therefore, the ginger extract could be used as alternative treatment for patients with AR.

Trial registration: Registered with ClinicalTrials.gov (Registration number: NCT02576808) on 15 October 2015.