1. Serious adverse events and withdrawals.
| Study | Serious adverse events | Number withdrawn due to side effects | Treatment arm from which withdrawn |
| Avunduk 2005 | No serious adverse events reported | No participants recorded to have withdrawn | N/A |
| Azevedo 1991 | No serious adverse events reported | 1 participant withdrawn | 1 from placebo group |
| Canonica 2003 | No serious adverse events reported | 2 participants withdrawn | 1 from azelastine and 1 from placebo |
| Carr 2013 | 1 serious adverse event reported unrelated to the treatment | 11 participants withdrawn | 4 from bepotastine besilate and 7 from placebo |
| Davies 1993 | No serious adverse events reported | 5 participants withdrawn | 2 from levocabastine group and 3 from placebo |
| Fujishima 2008 | No serious adverse events reported | No participants recorded to have withdrawn | N/A |
| Giede‐Tuch 1998 | No serious adverse events reported | No participants withdrawn due to side effects | N/A |
| Graue 1994 | No serious adverse events reported | 2 participants withdrawn | 1 from levocabastine and 1 from placebo |
| Hechanova 1984 | No serious adverse events reported | 12 participants withdrawn | 2 from cromoglycate group and 10 from placebo group |
| Höffling‐Lima 2001 | No serious adverse events reported | No participants recorded to have withdrawn | N/A |
| James 2003 | No serious adverse events reported | 4 participants withdrawn due to side effects | 1 from azelastine, 2 from cromoglycate, and 1 from placebo |
| Katelaris 2002 | No serious adverse events reported | 2 participants withdrawn | 1 from olopatadine group, 1 from cromolyn group |
| Kidd 2003 | 4 serious adverse events: 1) persistent photophobia and 2) conjunctivitis with corneal ulcer | 38 discontinued due to side effects | 8 from ketotifen, 15 from levocabastine, 15 from placebo |
| Lanier 2001 | No serious adverse events reported | No participants recorded to have withdrawn | N/A |
| Leino 1992 | No serious adverse events reported | 4 participants withdrawn | 3 from nedocromil and 1 from cromoglycate |
| Lenhard 1997 | No serious adverse events reported | 4 participants withdrawn | 2 from azelastine group and 2 from placebo group |
| McCabe 2012 | No serious adverse events reported | No participants recorded to have withdrawn | N/A |
| Melamed 1994 | No serious adverse events reported | No participants recorded to have withdrawn due to side effects | N/A |
| Melamed 2000 | No serious adverse events reported | No participants recorded to have withdrawn due to side effects | N/A |
| Moller 1994 | No serious adverse events reported | No participants recorded to have withdrawn due to side effects | N/A |
| Nazarov 2003 | No serious adverse events reported | 1 participant withdrawn due to side effects | 1 participant from azelastine group |
| Petzold a,b,c 2002 | No serious adverse events reported | No participants recorded to have withdrawn due to side effects | N/A |
| Sabbah 1998 | No serious adverse events reported | 1 participant withdrawn | 1 participant from azelastine group |
| Sarker 2011 | No serious adverse events reported | No mention of participants withdrawing due to side effects | N/A |
| Secchi a 2000 | No serious adverse events reported | 1 participant discontinued due to side effects | 1 participant from emedastine |
| Secchi b 2000 | No serious adverse events reported | No mention of participants withdrawing due to side effects | N/A |
| Trinquand 1999 | No serious adverse events reported | No mention of participants withdrawing due to side effects | N/A |
| Varguez‐Rodriguez 2009 | No serious adverse events reported | No participants recorded to have withdrawn | N/A |
| Verin 2001 | No serious adverse events reported | 3 participants withdrawn | 3 participants from emedastine group |
| Wertheimer 1997 | No serious adverse events reported | No participants recorded to have withdrawn due to side effects | N/A |
N/A: not applicable