Zoloft (sertraline) What is vardenafil used for a drug used for treating depression, anxiety and obsessive compulsive disorder. Launched in 1992 it has since been used in over 10.2 billion patient days of therapy. In clinical trials, What is vardenafil used for 50% of patients taking sertraline showed signs of improvement as opposed to a typical placebo response of 32% (mulrow).