Adverse events reported in ≥3% of patients in either treatment group by system organ class
| Azathioprine (n=41) | Mesalazine n=(37) | |
| Blood and lymphatic system disorders | ||
| Leucopenia | 7 (17.1%) | 0 |
| Anaemia | 3 (7.3%) | 0 |
| Eye disorders | ||
| Conjunctivitis | 2 (4.9%) | 0 |
| Gastrointestinal disorders | ||
| Abdominal pain/proctalgia | 8 (19.5%)/0 | 8 (21.6%)/2 (5.4%) |
| Nausea/vomiting | 4 (9.8%)/4 (9.8%) | 1 (2.7%)/1 (2.7%) |
| Pancreatitis | 6 (14.6%) | 0 |
| Flatulence | 3 (7.3%) | 2 (5.4%) |
| Toothache | 3 (7.3%) | 1 (2.7%) |
| Dyspepsia | 1 (2.4%) | 3 (8.1%) |
| Crohn's disease deteriorated/diarrhoea | 0/0 | 2 (5.4%)/1 (2.7%) |
| General disorders and administration site conditions | ||
| Influenza-like illness | 4 (9.8%) | 1 (2.7%) |
| Fever | 2 (4.9%) | 2 (5.4%) |
| Fatigue | 1 (2.4%) | 2 (5.4%) |
| Infections and infestations | ||
| Nasopharyngitis | 17 (41.5%) | 10 (27.0%) |
| Rhinitis | 2 (4.9%) | 3 (8.1%) |
| Influenza | 1 (2.4%) | 4 (10.8%) |
| Gastroenteritis | 1 (2.4%) | 2 (5.4%) |
| Respiratory tract infection | 0 | 2 (5.4%) |
| Urinary tract infection | 0 | 2 (5.4%) |
| Injury, poisoning and procedural complications | ||
| Confusion | 2 (4.9%) | 1 (2.7%) |
| Arthropod sting | 0 | 2 (5.4%) |
| Musculoskeletal and connective tissue disorders | ||
| Arthralgia | 2 (4.9%) | 1 (2.7%) |
| Back pain | 2 (4.9%) | 3 (8.1%) |
| Joint stiffness | 0 | 2 (5.4%) |
| Nervous system disorders | ||
| Headache | 9 (22.0%) | 13 (35.1%) |
| Sciatica | 0 | 2 (5.4%) |
| Psychiatric disorders | ||
| Depression | 0 | 2 (5.4%) |
| Reproductive system and breast disorders | ||
| Dysmenorrhoea | 4 (9.8%) | 2 (5.4%) |
| Respiratory, thoracic and mediastinal disorders | ||
| Pharyngolaryngeal pain | 3 (7.3%) | 1 (2.7%) |
| Cough | 1 (2.4%) | 3 (8.1%) |
| Allergic rhinitis | 1 (2.4%) | 2 (5.4%) |
| Surgical and medical procedures | ||
| Tooth extraction | 2 (4.9%) | 0 |
| Vascular disorders | ||
| Hypotension | 1 (2.4%) | 2 (5.4%) |