ORIGINAL RESEARCH—ED PHARMACOTHERAPYTiming of Dose Relative to Sexual Intercourse Attempt in Previous Sildenafil Citrate Users Treated with Tadalafil
Introduction
Therapeutic options for the treatment of erectile dysfunction (ED) have expanded significantly with the introduction of phosphodiesterase type 5 (PDE5) inhibitors. These oral therapies afford patients a noninvasive treatment and are favored by men with ED [1]. While all PDE5 inhibitors interfere with activity of the PDE5 enzyme [2], they differ substantially in their pharmacokinetic profile and duration of action. According to its reported clinical effectiveness, patients taking sildenafil citrate (sildenafil) are commonly instructed to take the medication up to 4 hours before sexual activity [3]. In contrast, tadalafil has been shown to be effective up to 36 hours after dose [4].
Results from studies with tadalafil examining timing of sexual behavior indicate that patients with ED use the 36‐hour period of tadalafil regardless of age, ED severity, or previous sildenafil use [5, 6]. Little is known about sex patterns of men treated for ED, specifically whether differences in the therapeutic window and related dosing instructions are associated with changes in patients’ sexual behavior when using different PDE5 inhibitors.
The goal of this study was to examine to what extent prior sildenafil users modified their sexual intercourse and drug intake timing behavior when exposed to tadalafil with respective dosing instructions. It is not known how sildenafil experienced patients change their behavior with new dosing instructions that suggest a broader window of opportunity from dose to sexual intercourse (while on tadalafil). Patients recruited into this large, multinational study were current users of sildenafil who, having completed a minimum of 10‐week continuous treatment with sildenafil (including 4 weeks on‐study), were then switched to treatment with 20 mg tadalafil.
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Study Population
A total of 2,760 patients from 173 centers in 21 countries (Malaysia, Taiwan, Hong Kong, Philippines, Singapore, Australia, New Zealand, Czech Republic, Poland, Russia, Slovakia, Turkey, Israel, Brazil, Peru, Venezuela, Colombia, Mexico, Costa Rica, Chile, and Puerto Rico) participated in the study.
Men were eligible for the study if they were at least 18 or 21 years of age (depending on country requirements) and had at least 3‐month history of ED (defined as a consistent change in the quality
Subjects
Enrolled patients were of diverse ethnicity and showed predominantly a moderate severity of ED (66%) as assessed by the investigator. The median duration of sildenafil use prior to enrollment was 474 days and the most commonly used doses of sildenafil were 50 mg (60.5%) and 100 mg (34.2%). Baseline patient characteristics are presented in Table 1.
Of the 2,760 men enrolled in this study, 269 did not complete all visits. For those patients who did not complete the study, 96 withdrew during the
Discussion
Sex patterns of men taking treatment for ED may be influenced by multiple factors including biological, social, psychological, and cultural. The goal of the present study was to provide insight into the behavior of long‐term sildenafil users, when treated with tadalafil and receiving specific dosing instructions. Although statistically significant differences were observed between treatments for drug exposure and frequency of sexual intercourse attempts per week, these may not be clinically
Conclusion
Therapeutic options for oral treatment of ED differ in their pharmacological profile and duration of action. The present study attempts to show that when previous sildenafil users changed their treatment to tadalafil and were instructed to explore its period of efficacy, they altered their timing of dose to sexual intercourse attempts. Specifically, these patients showed a propensity to administer tadalafil more in advance of sexual activity and earlier during the day compared with their
Acknowledgments
The authors would like to acknowledge the invaluable contribution of all site investigators who participated in the study. In addition, we are very grateful to Philippa Clarke and Zbigniew Kadziola for their contribution to statistical analysis of the study data.
Conflict of Interest
Funding for this study was supported by Lilly‐ICOS LLC. Yulia Dyachkova and Vladimir Kopernicky are employees of Eli Lilly and Company. Caroline Markey was an employee of Eli Lilly and Company during the study and is currently employed by Novartis. Mariano Sotomayor is a member of Lilly and Bayer advisory boards. Sidney Glina is a member of Bayer, Lilly ICOS, and Pfizer advisory boards and is a clinical investigator for GlaxoSmithKline, Pfizer, and Jansen‐Cilag.
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2010, Journal of Sexual MedicineCitation Excerpt :Interestingly, one study showed that women's preference were similar to those of men when using tadalafil or sildenafil, with some women preferring tadalafil because of relaxed, satisfying, and longer-lasting sexual experiences [18]. Although, the extent to which sexual behavior alters is not uniform across geographical regions [19], prior sildenafil citrate users modified their sexual intercourse and drug intake timing behavior when exposed to tadalafil with respective dosing instructions; the proportion of intercourse attempts per patient made >4 hours after dose was considerably higher during the tadalafil than the sildenafil treatment period [20]. These patients reported improvements in self-confidence, spontaneity and fewer time concerns.
Timing of dose relative to sexual intercourse attempt in previous sildenafil citrate users treated with tadalafil: A geographical comparison from a single arm, open-label study
2009, Journal of Sexual MedicineCitation Excerpt :The present study was conducted to examine to what extent prior sildenafil citrate users modify their sexual intercourse and drug intake timing behavior when exposed to tadalafil with respective dosing instructions. Results for the overall study population, which included 2,760 patients from 21 countries, have been published previously [5]. This report reexamines those data by geographical region.
Impact of the pharmacokinetic properties of PDE5 inhibitors on the dose/sexual intercourse interval
2008, Progres en UrologieTherapeutic response after first month of tadalafil treatment predicts 12 months treatment continuation in patients with erectile dysfunction: Results from the DETECT study
2008, Journal of Sexual MedicineCitation Excerpt :Partner and couple issues are also thought to contribute to treatment discontinuation [18]. Tadalafil is unique among the commercially approved PDE5 inhibitors because it has a long period of responsiveness that lasts up to 36 hours after dosing and can be taken with or without food [11,19–23]. These characteristics of tadalafil may facilitate its correct use in a real-life setting and could increase patient response and satisfaction [24,25].
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