Study	Reason for exclusion
Aho 1991	Study duration < 4 h
Al‐Khtoum 2006	Administered preoperatively
Albrecht 1992	Wrong route of administration
Anil 2016	Administered intraoperatively
Arslan 2009	Abstract with insufficient data for analysis
Baroni 1983	Wrong route of administration
Bhoyar 2015	Administered intraoperatively
Bossi 1984	Wrong route of administration
Bricker 1987	Administered preoperatively
Campbell 1990	Administered preoperatively
Carlborg 1987	Wrong route of administration
Chelly 2013	Not double‐blind
Chongsomchai 2009	Abstract with insufficient data for analysis
Daniels 2013	Multiple‐dose study with no first‐dose data
Daniels 2016	Multiple‐dose analysis of 2 studies with no first‐dose data
De La Paz 2009	Administered preoperatively
Elliott 2000	Wrong route of administration
Forrest 2002	Multiple‐dose study with no first‐dose data
Frame 1986	Not double‐blind
Frezza 1985	Fewer than 10 participants in each arm
Gan 2016	Multiple‐dose analysis of 2 studies with no first‐dose data
Gan 2017	Multiple‐dose analysis of 2 studies with no first‐dose data
Gunes 2011	Administered intraoperatively
Henrikson 1982	Wrong route of administration
Hernandez 1997	Wrong route of administration
Hultman 1989	Wrong route of administration
Hynes 1997	Wrong route of administration
Hynes 2006	Letter
Iwabuchi 1980	Wrong route of administration
Izquierdo 1995a	Not double‐blind
Kilickaya 2012	Administered intraoperatively
Kose 2012	Abstract with insufficient data for analysis
Kvolik 2010	Abstract with insufficient data for analysis
Labrada 2004	Administered preoperatively
Laitinen 1992	No baseline pain assessment
Litke 1997	Wrong route of administration
Lopez‐Carriches 2005	Wrong route of administration
Lovett 1994	Wrong route of administration
Manso 1991	Wrong route of administration
Mastronardi 1988	Wrong route of administration
Mehrotra 1998	Wrong route of administration
Metternich 1998	Wrong route of administration
Moffat 1990	Wrong route of administration
Naclerio‐Homem 1996	Administered preoperatively
Nelson 1993	Wrong route of administration
Pellerin 1989	Wrong route of administration
Philip 1985	Wrong route of administration
Rautela 1998	Wrong route of administration
Reyes 1988	Wrong route of administration
Samimi 2014	Wrong route of administration
Sandin 1993	Wrong route of administration
Silvanto 2002	Multiple‐dose study with no first‐dose data
Thienthong 2012	No 4‐ to 6‐hour data
Zohar 2006	Administered intraoperatively