Study	Reason for exclusion
Blackie 1990	Cross‐over design
Buchman 1994	The primary outcome was not clinical; pharmacokinetic study
Gelb 1989	Cross‐over design
Koller 1990	Cross‐over design
Lange 1991	This study has recruited part of the same population from Greene 1990; the primary outcome was not clinical
Lorentz 1991	Cross‐over design
Lu 1995	Cross‐over design
Maurri 1990	Not randomised
Moore 1991	Cross‐over design
Ostergaard 1994	Cross‐over design
Perlmutter 1989	Cross‐over design
Relja 1993	Not randomised
Tsui 1986	Cross‐over design
Tsui 1988	The primary outcome was not clinical
Yoshimura 1990	This study has recruited part of the same population from Gelb 1989