Premature Ejaculation Treated by Local Penile Anaesthesia in an Uncontrolled Clinical Replication Study.

Premature or rapid ejaculation (PE) is probably the most frequently occurring sexual dysfunction in men, affecting nearly 30% at some time in their lives (Laumann, Gagnon, Michael, & Michaels, 1994; Spector & Carey, 1990). For many years behavioral therapy was the only treatment available and accepted: the start-stop method (Semans, 1956) and the squeeze method (Masters & Johnson, 1970). In recent years a number of studies have been carried out to test the efficacy of psychopharmacological drugs, more specifically anti-depressants (Crenshaw & Goldberg, 1996; Riley, Peet, & Wilson, 1993; Rowland, Cooper, & Slob, 1998; Rowland & Slob, 1997; Waldinger, 1997). Most of the drugs (e.g., clomipramine and paroxetine) appeared to be fairly effective in postponing ejaculation (Rowland et al., 1998), both when taken on a daily basis (Waldinger, Hengeveld, Zwinderman, & Olivier, 1998) and when taken as needed, about 5 to 24 hrs before anticipated sexual activity (Haensel, Rowland, Kallan, & Slob, 1997; Strassberg, de Gouveia Brazao, Rowland, Tan, & Slob, 1999).

An alternative type of treatment is the local application of an anaesthetic ointment to the penis. Little has been done to scientifically study the effectiveness of such a treatment. One example is the research published by the Korean investigators who used a topical cream based on the traditional Chinese Royal Herb Remedy, SS-cream, which consists of 9 kinds of natural products (Xin, Choi, Lee, & Choi, 1997). A second example is the open pilot study on the use of prilocaine/lidocaine cream published by Berkovitch, Keresteci, and Koren (1995). They reported promising results, but detailed data substantiating the effectiveness were scarce. In fact, only the effect of the cream on duration of coitus was reported using a 4-point scale (-1 = less than baseline; 0 = no change; 1 = better; 2 = excellent). Five of their subjects reported an improved ejaculatory latency of 15 to 20 mins after intromission; in four this was 5 to 10 mins, and in two subjects there was no improvement (Berkovitch et al., 1995).

This prompted us to carry out the present, more detailed investigation with the use of the prilocaine/lidocaine cream. Although Berkovitch et al. (1995) recommended that a double-blind, placebo-controlled trial be done, we were unable to do so. Therefore, we decided to replicate their methodology of cream application exactly, but to add a collection of detailed sexological data by way of questionnaires.

METHOD

Subjects were recruited through an interview with the first author in a local newspaper, in which they were invited to apply by telephone for participation in this prospective study. Inclusion criteria were suffering from rapid ejaculation (i.e., ejaculation before or within 1 to 2 mins following penetration), age between 20 and 70, stable heterosexual relationship with a partner willing to participate in the study, and a coital frequency of at least once a week. Furthermore, participants needed to have sufficient knowledge of the Dutch language to fill in the questionnaires, and to be free from diseases or medication known to affect sexual functioning.

Of 27 men who originally applied and were eligible for inclusion, 15 subjects completed the study. Applicants who did not complete the study did so for various reasons: refusal of partner to participate (n = 3), no real PE (i.e., latency to ejaculation 3 to 4 min; n = 1) or concomitant erectile dysfunction (n = 1), reluctance to use the cream (n = 3), refusal to participate following receipt of questionnaire (n = 2), and failure to supply data on coitus without cream (n = 2). All data presented here were obtained through questionnaires (mailed in stamped envelopes provided by the investigators) and occasionally amplified through telephone contact.

Following tentative inclusion each participant received questionnaire A (social, medical, and sexual history; detailed questions about premature ejaculation; and sexual activities and possible dysfunctions over the previous four weeks). On return of questionnaire A the participant was sent a package containing 12 condoms, 5 tubes of 5 g prilocaine/lidocaine cream, and questionnaire B (a daily record of sexual activities with or without the use of the cream). Participants were invited to report on several sexual encounters with the use of the cream and a condom, and on two to three encounters without the cream. They were asked to fill in questionnaire B after each sexual activity and to return it to the investigators after approximately 4 to 6 weeks.

Upon receipt of questionnaire B by the investigators, the participants were sent questionnaire C, containing specific questions about their subjective experiences with the use of the condoms and cream.

All of these questionnaires have been employed before and were designed for studies in patients with various types of sexual dysfunction (see Haensel et al., 1997; Rowland et al., 1998; Strassberg et al., 1999). For the present study some specific questions were added.

Instructions about the use of cream and condom were an exact replication of the procedures described by Berkovitch et al. (1995). Half a tube of cream had to be applied to the glans penis and penile shaft, and had to be covered with a condom (to ensure the presence of the cream only on the penis and not elsewhere). After 10 mins (the time it takes to become effective), the condom had to be removed, the cream thoroughly wiped from the penis to avoid possible numbing effect of the cream on the female's genitalia, and sexual activity could be undertaken for each subject. Two mean values were calculated from the daily logs (questionnaire B): one for the items obtained without the cream, and one for the items obtained after the use of the cream.

RESULTS

From Table 1 it appears that all participants in the study were sexually active, and that they did, indeed, suffer from premature ejaculation with a lack of major erectile dysfunction (only 4 of 15 reported a less than full erection occasionally during sex activity). It should be emphasized that some of the mean values in Table 1 represent scores rather than time units (see footnote in Table 1). Thus, the estimated duration of foreplay was approximately 6 to 10 mins, and the estimated duration between penile intromission and ejaculation is between 1 and 2 mins, with less than 8 pelvic thrusts. Ejaculation prior to penile intromission occurred in 31% of occasions, with only 4 of the 15 subjects never experiencing this.

Table 1. Social and Sexual Aspects of Subjects With Premature or Rapid Ejaculation Prior to the Use of Prilocaine/Lidocaine Cream.

                               Mean    SD     Range

Age (years)                    43     11      21 - 64

Duration relationship          14.3   11.4   0.5 - 40
(years)

Monthly number of:
  Morning erections            13      9.5     0 - 30
  Sexual intercourses           6.5    4.8     1 - 20
  Masturbations                 2.1    2.5     0 - 8

Duration of foreplay(a)         3.9    0.9     3 - 5

Duration till ejaculation(a)
  With sexual intercourse       1.4    0.6     1 - 3
  With masturbation             1.8    0.9     1 - 4

Number of pelvic thrusts
till ejaculation(b)             2.2    0.9     1 - 4

Ejaculation prior to
intromission (% occasions)     31     33       0 - 100

Sense of control(c) over
ejaculation during              1.3    0.5     1 - 2
sexual intercourse

Full erection with sexual
activity (% occasions)         92     15      50 - 100

Note. Number of subjects = 15

(a) Estimated duration in minutes: 1 = 0 - 1 min, 2 = 1 - 2 min, 3 = 3 - 5 min, 4 = 6 - 10 min, 5 = 11 - 15 min.

(b) Estimated number: 1 = 0 - 3, 2 = 4 - 7, 3 = 8 - 12, 4 = 13 - 20.

(c) 1 = none, 4 = moderate, 7 = complete.

Effects of the anaesthetising cream on various aspects of sexual activity are depicted in Table 2. There is a highly significant prolongation of the interval between penile intromission and ejaculation, from an estimated less than 2 mins without the cream to 8 mins with the cream applied to the penis (albeit with quite some variance, i.e., a large SD). Also the sense of control over ejaculation (i.e., being able to delay the event) had highly significantly increased. Although the degree of sexual arousal had not been affected significantly by the use of the cream, there was a nearly significant lowering effect on the degree of erection. Nevertheless, the overall subjective experience of the male's satisfaction with intercourse had improved with the use of the cream.

Table 2. Aspects of Sexual Intercourse of Subjects With Premature or Rapid Ejaculation With and Without the Use of an Anaesthetising Cream.

                                        Coitus
                        Coitus with     without
                           cream        cream       Wilcoxon
                                                    signed
                        Mean    SD    Mean    SD    ranks test

Number of sexual
intercourses            3.9     2.0   2.2     0.9

Degree of sexual
arousal(a)              6.9     2.1   7.6     2.1   n.s

Degree of erection(a)   7.9     2.0   8.8     1.5   p = 0.051

Sense of control
over ejaculationa       4.7     3.1   2.5     2.2   p = 0.005

Duration of sexual
intercourse till        489     465   115     142   p = 0.003
ejaculation (sec)

Subjective experience
of intercourse with     2.9     0.8
cream(b)

Note. Number of subjects = 15.

(a) 1 = minimal, 10 = maximal.

(b) Compared with subjective experience without cream: 1 = worse, 2 = no change, 3 = better, 4 = excellent.

It is of further interest that the male subjects reported a significant increase in the occurrence of orgasms of their female partners: from 29% without to 69% with use of anaesthetising cream during sexual intercourse (p = 0.005).

Unpleasant effects of the cream were reported by 10 of the 15 subjects. The most frequently heard complaint was some degree of numbness of the penis with a less than full erection, although intromission was usually not impaired. Three of the 15 subjects reported an occasional incapacity to reach orgasm during sexual intercourse, varying from one out of four to two out of three occasions. This occurred only with the use of the cream. There was one participant, one of the dropouts not included in the data analysis because of incomplete data, who could not have an erection with the use of the cream.

DISCUSSION

The present study confirms and amplifies the recent work of Berkovitch et al. (1995); Choi, Xin, and Cho (1993); and Xin et al. (1997) who demonstrated that local application of an anaesthetising cream or ointment to the penis could alleviate the occurrence of rapid ejaculation in men. We used prilocaine/lidocaine cream because of its easy availability, and we used questionnaires to obtain detailed sexological information. In our subjects the cream caused a significant prolongation in the estimated time between intromission and ejaculation from about 2 mins to about 8 mins. Also, the sense of control over ejaculation had significantly improved, and the occurrence of the female partner's orgasm (according to the male participant) had significantly increased.

One of the unpleasant features of the present study appeared to be the obligatory use of a condom to ensure that both the penile glans and the shaft were exposed to the cream. Some of our patients reported that application of the cream limited to the glans was quite efficacious (apparently not all subjects followed the design!). In retrospect this could have been anticipated in view of the work by Xin, Choi, Seong, and Choi (1995). They showed that the latency of somatosensory-evoked potentials in PE patients after application of their SS-cream to the glans penis was significantly longer than without the cream, whereas the latency of the penile shaft was not affected by the cream. In their clinical study (Xin et al., 1997) their patients applied SS-cream only to the glans penis, which appeared to be as effective as in our present study. We recommend that the prilocaine/lidocaine cream need only be applied to the glans penis, which makes the use of the condom optional. This seems particularly relevant for PE-patients with an intact foreskin.

The occurrence of mild erectile dysfunction and some lowering of sexual arousal in some of our patients can possibly be avoided by reducing the amount of cream. Patients have to titrate their own optimal dose of prilocaine/lidocaine cream. Also, restricting the cream to the glans only could possibly further diminish the likelihood of erectile dysfunction.

It would be interesting to know the efficacy of the cream with longterm use (e.g., one year). The efficacy may diminish after some time. In other cases the cream may no longer be needed because the sexual dysfunction has disappeared, as we have seen in patients with erectile dysfunction after discontinuation of autoinjection therapy (e.g., Rowland, Boedhoe, Dohle, & Slob, 1999).

In a new study, ideally double blind and in some way placebo controlled, female partners should be more explicitly involved with their own questionnaires. This would ensure a more complete assessment of the effectiveness of the treatment. Furthermore, oral interviews of the couple before and after the study are recommended.

CONCLUSION

Prilocaine/lidocaine cream applied to the penis may be an effective treatment for men with premature or rapid ejaculation. Patients should be advised to titrate their own optimal effective amount of cream, presumably between 1 and 2.5 g. When anaesthesia of the glans penis suffices, the foreskin, when present, may obviate the use of a condom to allow the active substances of the cream to penetrate the skin.

REFERENCES

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Haensel, S. M., Rowland, D. L., Kallan, K. T. H. K., & Slob, A. K. (1997). Clomipramine and sexual function in men with premature ejaculation and controls. Journal of Urology, 156, 1310-1315.

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Waldinger, M. D., Hengeveld, M. W., Zwinderman, A. H., & Olivier, B. (1998). Effect of SSRI antidepressants on ejaculation: A double-blind, randomized, placebo-controlled study with fluoxetine, fluvoxetine, paroxetine, and sertraline. Journal of Clinical Psychopharmacology, 18, 274-281.

Xin, Z. C., Choi, Y. D., Lee, S. H., & Choi, H. K. (1997). Efficacy of a topical agent SS-cream in the treatment of premature ejaculation: Preliminary clinical studies. Yonsei Medical Journal, 38, 91-95.

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Manuscript accepted January 17, 2000

A. Kloos Slob, Antien van Berkel, and Jacob J. van der Werff ten Bosch Erasmus University Medical Center Rotterdam (EMCR) Rotterdam, The Netherlands

Thanks are due to Dr. W. C. J. Hop for his statistical advice; Dr. P. Brasem from Astra Pharmaceutics bv for free supply of the lidocoine/prilocaine cream and a small grant to cover overhead expenses; and F. Julsing, director NVSH-supply department, for a free supply of condoms.

Address correspondence to A. Koos Slob, Ph.D., Department of Endocrinology & Reproduction, Erasmus University Medical Center Rotterdam (EMCR), P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.