In the treatment of erectile dysfunction in patients with comorbidities such as obesity, diabetes, hypertension, cardiovascular disease, chronic kidney disease, depression, or metabolic syndrome, phosphodiesterase type 5 (PDE-5) inhibitors are most commonly used, including sildenafil, tadalafil, and vardenafil; in selected cases, avanafil is also used [29]. This evidence concerns the gene PDE5A and diabetes mellitus.