Hwancheol Son, Kwanjin Park, Soo-Woong Kim, Jae-Seung Paick

Sildenafil produce satisfactory results for the treatment of erectile dysfunction (ED). In a 11 double-blind placebo-controlled study, 46.5 % to 87 % of ED patients reported improved erection [1]. Despite the success of the sildenafil treatment, many patients discontinue sildenafil for various reasons. In a study by Young et al [2], the drop-out rate from sildenafil treatment was reported to be about 10 % in black and Hispanic Americans, whereas in Asian patients, the drop-out rate has been reported as only 1.8 % - 4.5 % [3, 4]. Padma-Nathan et al [5] indicated that 32.1 % of patients were lost before the end of a 3-year treatment period. The most common reason given for drop-out is 'adverse events' which may or may not be treatment-related.

All of the previously mentioned drop-out rates were obtained from clinical studies of sildenafil treatment. However, we believe that the drop-out rates are actually higher in real-life clinical settings and therefore, we undertook to determine compliance to medication and the reasons for discontinuation with their respective contributions after successful restoration of erectile function with sildenafil medication.

This study was conducted from May to July 2002. One hundred fifty six patients, aged 38 to 69 with a mean of 54.6 years (Table 1), whose erectile function (EF) domain score (Q1 to Q5, Q15; score range: 1 to 30) of the 15-item International Index of Erectile Function (IIEF) increased to 26 or more after sildenafil medication, were included in this study. Eleven patients (7.1 %) had injection therapy for ED, however, the majority of patients were not exposed to ED treatment. At least two prescriptions and 4 administrations were performed in every subject. Sildenafil was prescribed only when patients had stable sexual partner(s) and escalation or reduction of dose was permitted within ranges 25-100 mg according to patients need and side effects. Six months after first sildenafil prescription, compliances to medication and the reasons for discontinuity were reviewed by chart or surveyed by telephone.

Fifty-four (34.6 %) of the 156 successfully treated patients discontinued sildenafil medication. The average of duration of ED were 29.823.2 in the continuation group and 27.023.4 in the discontinuation group. The average of pre-treatment IIEF EF domain score were 15.94.0 in continuation group and 16.73.7 in discontinuation group. There is no significant difference in age, duration of ED and pre-treatment IIEF EF domain score between the two groups (Table 1). There were more BPH (benign prostatic hyperplasia) patient in the discontinuation group (16.7 %) than in the continuation group (23.5 %), however, there is no significant difference in co-morbid disease between the two groups (Table 2).

Table 2. Sildenafil discontinuation and co-morbid disease. * Benign prostatic hyperplasia, + Cardiovascular accident

The reasons given for discontinuance were lack of the partners?emotional readiness for the restoration of sexual life after long-term abstinence (12/54, 22.2 %), lack of the patients?emotional readiness for the restoration of sexual life after long-term abstinence (8/54, 14.8 %), fear of possible drug side effects (10/54, 18.5 %), recovery of spontaneous erection (8/54, 14.8 %), postponement of ED treatment because of treatment for co-morbid disease(s) (6/54, 11.1 %), unwillingness to accept drug-dependent erection (4/54, 7.4 %), high drug cost (2/54, 3.7 %), unacceptability of planned sexual activity (2/54, 3.7 %) and a lack of sexual interest (2/54, 3.7 %) (Table 3).

Erectile dysfunction (ED) is both a prevalent and distressing condition, which prompts people to find an adequate solution. In the clinical setting, patients are recommended one of several treatment options, such as, oral medication, intracavernosal injection (ICI) or vacuum constriction devices (VCD). At present, the treatment of ED has shown a high rate of success. However, ED is not a life-threatening disease, and therefore, the discontinuation of treatment makes little difference in terms of the major functions of the body.

Before the introduction of sildenafil, intracavernosal injection (ICI) was one of the most common treatments used for ED. Even though ICI produced good results, many patients discontinued treatment for various reasons, including penile pain, inadequate response, fear of the needle, unnaturalness and loss of sex drive [6]. In clinical studies, the patient drop-out rate has varied from 0 - 47 % [7]. In our clinic, drop-out rates of Korean patients was about 50 % and in common with other reports, the reason most frequently given for Korean drop-out was the fear of needle or injection (Paick J-S, Lee KC, Kim SW, Lee C, Kim SW. Trimix intracavernosal self-injection therapy. Unpublished data). Similar to ICI, Pangkahila [8] reported 40 % drop-out rate in intraurethral alprostadil therapy and the most frequent reason for drop-out was pain, either during the application, during erection or during intercourse.

The vacuum constriction device is very safe when used properly and is one of the least costly treatment options available. It became popular during the 1990s as an effective and safe treatment for ED. Though, the erection produced by a vacuum device differs from a physiologic erection or one produced by ICI in many patients, it produces an erection that is close to normal and sufficiently rigid for coitus [6]. Patient satisfaction rates have been reported to range from 68 % to 83 % [9]. In their retrospective review, Derouet et al [10] reported a 30.9 % drop-out rate at 16 weeks. Dutta and Eid [11] reported a 65 % attrition rate at 4 months period and found that of those who discontinued, 63 % did not seek further treatment. If this 63 % wanted to recover their erectile function, they should have sought further treatment; however, they did not. This finding implies that the simple recovery of a rigid erection is not sufficient for the resumption of sexual life. For those that achieved erectile function, pain and cumbersomeness were the reasons most frequently given for discon-tinuance.

In the present study, 54 (34.6 %) of 156 patients discontinued sildenafil medication. This drop-out rate is similar to those of ICI and VCD. However, unlike ICI and VCD, the reasons for sildenafil medication discontinuance were mainly emotional or relationship-oriented. The fear of possible drug side effects, unnaturalness, or high drug cost were other less prevalent reasons (Table 3). Compared to the other treatments for ED, oral medication offers many advantages. It is more convenient, easily administered non-invasively and produces a more natural erection. However, it has similar drop-out percen-tage, which means the simple recovery of a more rigid erection is not enough to restore sexual life. To completely restore sexual life certain conditions other than erection should be met and the most important concerns are the emotional readiness of both partners. Just like people in other oriental countries, Korean rarely discuss sexual problem with their partners. In urology clinics, we met many Korean ED patients who want to hide their problem and treatment from the partners. We can easily guess that this kind of attitude interfere with good sexual relationship even after successful restoration of rigid erection. Accordingly, we suggest that both patient and partner education and counseling are essential aspects of drug therapy and are needed to promote the successful recovery of sexual life.

There are many limitations for the generalization of results of this retrospective study. The pretreatment IIEF EF domain scores of subjects in clinical studies are about 13 to 14 [4, 12], however, the score (16.2) of this study is much higher. Additionally, the average duration of ED was about 28.8 month only. Because we investigated subjects whose IIEF EF domain score increased to 26 or more after sildenafil medication, there is the possibility of choosing subjects with relatively better erectile function. Retrospective study method, limited numbers of subjects, telephone survey, only 6-month follow up and cultural differences are limitation for generalization of the results of the resent study. However, this study showed that there is more than rigid erection in sexual relationship. Despite of many limitations of this study, the results showed clearly the importance of emotional readiness of both the patients and their partners. Including 'Fear of possible drug side effects' over a half of drop-out reason was what we can overcome with education and counseling. The introduction of effective oral medication for the treatment of ED solved many problems including pain and fear about therapy and even changed our practice pattern of ED [13], however, current treatment options are still a palliative one and more basic problems remain to be addressed. Couple-based education and counseling are essentially needed to promote the successful recovery of sexual life.