In vitro measurement of ejaculation latency time (ELT) and the effects of vardenafil on ELT on lifelong premature ejaculators: placebo-controlled, double-blind, cross-over laboratory setting

Abstract

The aim of this study is to measure the ejaculation latency time (ELT) and to evaluate the effects of vardenafil on ELT and rigidity parameters of patients with lifelong premature ejaculation (PE) in a laboratory setting. Double-blind, placebo-controlled, cross-over laboratory study was performed with 40 males with lifelong PE. As the subject ingested the placebo or vardenafil, real-time penile tumescence and rigidity monitoring began. Audiovisual sexual stimulation (AVSS) was performed 45 min later. The patient began vibratory stimulation to the frenular area at 8th minute of AVSS till ejaculation. A button has been placed under the cover where the patient presses to operate the vibrator. ELT was calculated in seconds with a chronometer. Following ejaculation, AVSS was stopped. The test was repeated with second medication in 7-15 days. Among 40 patients, the results of 17 could be evaluated. When the patient took placebo and vardenafil, mean ELTs were 62.7 and 189.5 s, respectively. When compared with placebo, vardenafil improved ELT significantly (P = 0.04). After the beginning of AVSS, time to first recorded base or tip rigidities was shorter and time to last recorded tip or base rigidities following ejaculation was longer than placebo; however, these differences were not significant (P > 0.05 for each). This laboratory design might be used to evaluate the effects of drugs on patients with ejaculation disorders. In this laboratory setting study, vardenafil exerted a threefold increase in ejaculation delay outside the vagina in patients with lifelong PE.