Table 1.

Study characteristics.

	Date range (recruitment)	Intervention	Duration	Trial type	Trial design	Blinding	Country of recruitment	n (baseline)	n (control)
Hegazy et al. (2024)22	2022–2023	Tadalafil	6 months	RCT	Parallel	Open label	Egypt	60	30
Fryk et al. (2023)23	2016–2019	Tadalafil	6 weeks	RCT	Crossover	Double blind	Sweden	18	18
Pofi et al. (2022)24	2014–2018	Tadalafil	20 weeks	RCT	Parallel	Double blind	Italy	122	61
Lee et al. (2022)25	2017–2018	Tadalafil	6 months	RCT	Parallel	Double blind	Republic of Korea	68	23
Derosa et al. (2022)26	Not reported	Avanafil	3 months	RCT	Parallel	Double blind	Italy	61	30
Liu et al. (2016)27	2011–2014	Sildenafil	12 weeks	RCT	Parallel	Double blind	The Netherlands	52	26
Scheele et al. (2016)28	Not reported	PF-00489791	12 weeks	RCT	Parallel	Double blind	Multiple	248	61
Kirilmaz et al. (2015)29	2010–2011	Sildenafil	3 months	RCT	Parallel	Not reported	Türkiye	83	41
Khazaal et al. (2014)30	2014	Tadalafil	8 weeks	RCT	Parallel	Double blind	Iraq	40	20
Giannetta et al. (2012)31	2008–2009	Sildenafil	12 weeks	RCT	Parallel	Double blind	Italy	59	29
Morano et al. (2007)32	2002–2003	Sildenafil	12 weeks	RCT	Parallel	Double blind	Italy	16	8
Grover-Páez et al. (2007)33	Not reported	Sildenafil	30 days	RCT	Parallel	Double blind	Mexico	40	20
Sáenz de Tejada et al. (2002)34	1999–2000	Tadalafil	12 weeks	RCT	Parallel	Double blind	Spain	216	71

The study characteristics of the 13 included trials are tabulated.