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- Original Article -

Regaining of morning erection and sexual confidence in patients with erectile dysfunction

Sae-Chul Kim

Department of Urology, Chung-Ang University Hospital, Seoul 156861, Korea

Abstract

Aim: To investigate how erectile dysfunction (ED) medications affect morning erection in patients with ED and how they respond to the return of morning erection.  Methods: This study was conducted in 120 patients who experienced successful intercourse with either tadalafil or sildenafil. Using a random face-to-face interview and a questionnaire (about the quality and number of days getting morning erection after using the two medications), the impact of the medications on the morning erections was investigated, and the participants were asked about their feelings on regaining morning erection.  Results: Of the respondents, 81% (68% of those with sildenafil and 99% of those with tadalafil) experienced morning erections after taking an oral ED medication. The men who took tadalafil mainly for 2 days with one dose, while those who took sildenafil experienced morning erections mainly for 1 day. The major sentiment upon regaining a morning erection was, "having more confidence as a man" (74%). Among the 96 respondents who experienced morning erections with tadalafil, 52% preferred tadalafil over sildenafil, not only because of freedom from concerns about a specific time to have relations, but also regaining morning erection.  Conclusion: Regaining a morning erection affects the recovery of confidence as a man and influences the preference for tadalafil over sildenafil. (Asian J Androl 2006 Nov; 8: 703_708)

Keywords:morning erection; sexual confidence; sildenafil; tadalafil; erectile dysfunction

Correspondence to: Dr Sae-Chul Kim, Department of Urology, Chung-Ang University Hospital, 224-1 Heoksuck-dong, Dongjak-gu, Seoul 156861, Korea.

Tel: +82-2-6299-1785, Fax: +82-2-822-8496
E-mail; saeckim@unitel.co.kr
Received 2005-12-25 Accepted 2006-06-16

DOI: 10.1111/j.1745-7262.2006.00212.x

1  Introduction

In the normal man, three to five erections occur nightly and account for up to 40% of total sleep time [1], with each erection lasting 25_35 min [2]. Nocturnal penile erection (NPE) is a naturally occurring, non-sexually stimulated phenomenon. The rigidity and duration of NPE are diminished with age, but the frequency does not change [3].

Morning erection is the last erection of the 3-5 NPE, and men occasionally discover the erection when they are awake in the morning. In general, men believe that the morning erection is a parameter of normal sexual health [4], and those who are not confident about their potency are used to relying on the presence of a morning erection to confirm their potency. Men with poor morning erection can be anxious about their sexual health. Confidence is critical to initiation of a better sex cycle. For this reason, weakness of the morning erection might affect confidence and, thereby, exert a negative influence on a man's sexual life.

The purpose of the present study is to investigate how ED medications affect morning erection in patients with ED and how they feel upon regaining morning erection.

2 Materials and methods

The study, partially sponsored by Lilly Korea, was conducted using a face-to-face interview and a questionnaire on 120 patients who had recent or current experiences with tadalafil and sildenafil, using a constant dose of each drug for more than four times, in the Seoul and Gyeonggi region of Korea between April and May 2005. The patients were randomly selected, with a quota in each age group, from those who were visiting urologic clinics of general hospitals. The interviewer asked a series of questions from the questionnaire and filled it out as interviewees answered. Age distribution (mean age: 60.0 years) was 45_54 years in 30 interviewees, 55_64 years in 30 interviewees, and 65 years or older in 60 interviewees. All the respondents had successful intercourse by using either tadalafil or sildenafil.

The questionnaire contained 17 questions, including number of days getting morning erection after taking oral phosphodiesterase type 5 (PDE5) inhibitors and its quality, their feeling on regaining a morning erection, its significance for maintaining confidence, and its impact attributable to the medication (see Appendix).

A two-way analysis of variance (ANOVA) was used to seek statistical differences among the groups. The two factors in the two-way ANOVA test were age of patient (45_54, 55_64, and over 65 years) and drug used (sildenafil or tadalafil).

3 Results

Of the respondents, 81% (n = 97) experienced mor-ning erections after taking an oral ED medication. Among them, 99% (n = 96) experienced morning erection with tadalafil, which was significantly higher than 68% (n = 66) with sildenafil (P < 0.0001). The response rate with tadalafil versus sildenafil, based on age, was 87% vs. 63% in the 45_54 years group, 83% vs. 60% in the 55_64 years group, and 75% vs. 48% in the 65 years or older group. There was a significant difference between sildenafil and tadalafil group in experiencing morning erection, regardless of age (P < 0.0001).

The respondents who used one dose of tadalafil experienced morning erections mainly for 2 days (50%), whereas those who used one dose of sildenafil mainly for 1 day (89%) (Table 1). Of the respondents, 85% (n = 97), regardless of age, who regained morning erections, were satisfied with the rigidity, compared with those they experienced when they were younger (Figure 1).

Among 96 respondents who experienced a morning erection with tadalafil, 52% (58% in the 45_54 year old age group, 64% in the 55_64 year old age group and 42% in the 65 year old or older age group) preferred tadalafil to sildenafil, not only because of successful intercourse, but also as a result of regaining a morning erection. The major sentiment (in first or second choice) for regaining a morning erection, was "having more confidence as a man" (74%), followed by "feeling healthier" (30%) and "feeling like being reborn or rejuvenated" (25%) (Table 2).

In response to a 7-point scale question (Q12) where 1 point means "definitely disagreed", 7 means "definitely agreed" and point ¡Ý5 was regarded as agreement to the question, 83% of 120 patients agreed to the question "Morning erection brings joy and energy into life", 83% agreed to the question "It affects my choice of ED medication whether a drug gives a morning erection or not", and 77% agreed to the question "Getting a morning erection is as important as having a successful intercourse to recover confidence".

4 Discussion

Compared with sildenafil, tadalafil has an extended terminal half-life, 17.5 h [5] vs. 3.5 h [6], suggesting a lengthened period of responsiveness. Based on the pharmacokinetics, tadalafil has a period of responsiveness of up to 36 h [7], whereas sildenafil was still able to produce/enhance an erection in response to sexual stimulation at 4_5 h after dose administration [8]. In the present study, there was a significant difference between sildenafil and tadalafil in patients experiencing a morning erection, regardless of age. However, 68% of the patients reported morning erections after taking sildenafil. Considering the short action duration, sildenafil would not be very effective in producing morning erection after being taken the previous night. However, clinical efficacy of sildenafil might be observed for upwards of two to three half-lives [9], and patients who have successful intercourse with sildenafil might get back morning erection through sildenafil-induced upregulated activation of endothelial nitric oxide synthase [10].

The two PDE5 inhibitors have been reported to be similarly efficacious and well tolerated [11, 12]. The different pharmacokinetic profiles result in unique attributes for the particular drugs and might translate into the reasons for treatment preference. In previous studies comparing patient preference for two ED medications, the majority of the patients who preferred tadalafil for the treatment of ED pointed out freedom from time concerns because of the long-acting characteristics of the drug as the first reason for the preference [13, 14].

When patients with ED have a spontaneous, strong morning erection after taking an ED medication and feel that their sexual function is regained, they might have much more confidence as a men. Using the Psychological and Interpersonal Relationship Scale [15], which was developed to evaluate outcomes associated with ED and its treatment, Dean et al. [16] report that the sexual self-confidence domain score of tadalafil (2.91) is significantly superior to that of sildenafil (2.75). In the drug attribute study by Dean et al. [14], an erection the next morning was a much more frequently-selected drug attribute of tadalafil (30.1%) over sildenafil (8.2%). In conjunction with the two reports, we assumed an association between sexual self-confidence and morning erection. In the present study, respondents who used tadalafil experienced more morning erections and more days of morning erections occurring than those who used sildenafil, regardless of age. A major sentiment upon regaining a morning erection was having much confidence as a man, which was also attributed to the preference for tadalafil over sildenafil, in addition to the freedom from time concerns about efficacy.

In conclusion, tadalafil users experienced more morning erections and more days of morning erections than sildenafil users, regardless of age. Regaining a morning erection affected the recovery of confidence as a man and influenced the preference for tadalafil over sildenafil.

Acknowledgment

This paper was sponsored by Lilly Korea.

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