Table 1.

Study design and demographic data

Study (year) [ref]	Country	Population characteristics		Study design
		No. of subjects	Age (years)	Type of trial	Dose	Dose frequency
Arowojolu et al., (2002) [30]	Nigeria	1160	19-35	Prospective comparative study	0.75 mg & 1.5 mg	Once & two split doses 12 h apart
Croxatto et al., (2004) [33]	Chile, Dominican Republic	58	18-40	Two-center, randomized, double-blind, placebo-controlled study	0.75 mg	Two doses given 12 h apart, or a single dose
Dada et al., (2010) [31]	Nigeria	3022	20-33	Randomized, controlled, double-blind, multicentre, non-inferiority trial	0.75 mg & 1.5 mg	Two doses, 12 h apart vs. a single dose
Durand et al., (2001) [18]	Mexico	45	29-35	Randomized, comparative study	0.75 mg	Two doses taken 12 h apart, at 0 h & after 48 h
Durand et al., (2005) [34]	Mexico	30	29-35	Randomized, comparative study	0.75 mg	Two doses taken 12 h apart, at 0 h & after 48 h
Gainer et al., (2007) [28]	Chile	12	18-32	—	1.5 mg	Once
Hapangama et al., (2001) [19]	Scotland	12	26-41	Prospective, randomized, double-blind, crossover study	0.75 mg	Two doses given 12 h apart
Johansson et al., (2002) [23]	Dominican Republic	5	18-45	Randomized, comparative study	0.75 mg & 1.5 mg	Once, two doses given 12 h apart, two doses given 24 h apart
Kook et al., (2002) [24]	USA	16	19-44	Open label study	0.75 mg	Twice, taken 12 h apart
Ngai et al., (2005) [32]	China	2071	20-34	Double-blind, randomized trial	0.75 mg	Every 24 h & every 12 h
Noé et al., (2010) [35]	Chile	388	18-38	Prospective, open-label, single-drug, single dose, uncontrolled clinical trial	1.5 mg	Once
Raymond et al., (2006) [36]	USA	120	18-38	Case-series study	1.5 mg	Once
Sambol et al., (2006) [29]	USA	22	13-16	Prospective, single-period, single center, open-label clinical trial	0.75 mg	Once
Tremblay et al., (2001) [25]	South Africa	24	18-26	Open, observer-blind, randomized study	0.75 mg	Once, two doses given 12 h apart, two doses given 24 h apart