Efficacy and Safety of Sinusitis Hevert SL Tablets Compared to Placebo in Adult Patients With Acute, Uncomplicated Rhinosinusitis

Inclusion Criteria: 1. Signed informed consent 2. Male and female outpatients, aged ≥ 18 and ≤ 75 years 3. Diagnosis of acute, uncomplicated (or recurrent acute) rhinosinusitis * characterized by Major Rhinosinusitis Symptom Score (MRSSinv) ≥ 8 and ≤ 15 points * individual score for facial pain/pressure (on bending) ≥ 1 (mild) and ≤ 2 (moderate) * with presence of symptoms ≤ 3 days prior to inclusion Out of the 5 main rhinosinusitis symptoms, at least 3 must be present. Among these, the presence of nasal congestion and facial pain / pressure (on bending) is mandatory. 4. Women of childbearing potential: willingness to use contraception methods Exclusion Criteria: Medical history * Diseases 1. Chronic rhinosinusitis (i.e. all forms and causes of persistent chronic rhinosinusitis) 2. Polyposis nasi, recent history 3. Infection of dental origin in the maxilla 4. Cystic fibrosis, recent history 5. Anatomical deviations of the nasal septum that significantly impair nasal and paranasal ventilation / air flow 6. Acute symptoms of a known allergic rhinitis 7. History of smoking within the last two years prior to study enrolment or current smoking habits 8. Patients with asthma 9. Known hypersensitivity to study medication or excipients (asteraceae, lactose, allergy to bee venom, etc.) 10. Underlying diseases leading to a significant immune deficiency 11. Signs or symptoms of bacterial sinusitis requiring antibiotic treatment (e.g. fever \>38.3°C, orbital complications, severe unilateral frontal headache or toothache) 12. Patients with progressive auto-immune diseases, tuberculosis, leukemia or leukemia-like diseases, multiple sclerosis, inflammatory diseases of the connective tissues, rheumatoid arthritis, Lupus erythematodes, HIV infection or other chronic viral diseases 13. Patients with untreated/unstable thyroid gland disorder (treatment should not include iodine supplementation) 14. Pre-menopausal women (last menstruation ≤ 1 year prior to informed consent) who: * are nursing or pregnant, * or are of child-bearing potential and are not practicing an acceptable method of birth control, or do not plan to continue using this method throughout the study. Acceptable methods of birth control include transdermal patch, intra uterine devices/systems (IUDs/IUSs), oral, implantable or injectable contraceptives, double barrier methods, sexual abstinence and vasectomised partner. 15\. Severe diseases of liver or kidney 16. Severe somatopathic, neurological and / or psychiatric diseases 17. Patients with malignant growth processes or cancer treatment within the last two years prior to study inclusion. 18\. History of alcohol or drug abuse * Medication 1. Treatment with systemic or nasal antibiotics or nasal or systemic corticosteroids within the last 4 weeks prior to study inclusion 2. Treatment with alternative medicine preparations (homeopathic and phytotherapeutical drugs) for treatment of common cold like symptoms or with immunomodulating properties (such as Echinacea), within the last 7 days prior to study inclusion 3. Treatment with decongestant (α-sympathomimetics on the day of study inclusion within 5 hours prior to screening and during the study) 4. Chronic use of decongestant remedies 5. Treatment with immunosuppressive medication 8 weeks prior to study inclusion and during the study for any condition 6. Systemic antiviral treatment such as aciclovir; zanamivir, or oseltamivir within 30 days prior to study inclusion 7. Patients requiring antibiotic treatment for any condition at study entry * General 1. Parallel participation in any other clinical study or participation in another study within less than 6 weeks prior to study inclusion, or previous participation in this same study 2. Legal incapacity and / or other circumstances rendering the patient unable to understand the nature, scope and possible impact of the study 3. Patients in custody by juridical or official order 4. Patients who have difficulties in understanding the language (German) in which the patient information is given 5. Patients who are employees of a trial center, the CRO, the sponsor or its authorised representatives or are relatives either of the study site staff, the CRO staff; the sponsor staff or its authorised representatives