Serotonin Transporter Promoter Region (5-HTTLPR) Polymorphism Is Not Associated With Paroxetine-Induced Ejaculation Delay in Dutch Men With Lifelong Premature Ejaculation

Abstract

Purpose: To investigate the association between the 5-HT-transporter-gene-linked promoter region (5-HTTLPR) polymorphism and 20-mg paroxetine-induced ejaculation delay in men with lifelong premature ejaculation (LPE).

Materials and methods: This was a prospective study of 10 weeks of paroxetine treatment in 54 men with LPE. Intravaginal ejaculation latency time (IELT) was measured by stopwatch. Controls consisted of 92 Caucasian men. All men with LPE were genotyped for the 5-HTTLPR polymorphism. Allele frequencies and genotypes of short (S) and long (L) variants of the polymorphism were compared between patients and controls. Associations between the LL, SL, and SS genotypes and fold increase of mean IELT were investigated.

Results: Of the 54 patients, 43 (79.6%) responded to 20-mg paroxetine treatment with an ejaculation delay, whereas 11 patients (20.4%) did not respond; 44%, 18%, and 18% of the patients showed a fold increase in mean IELT of 2-10, 10-20, and more than 20, respectively. Of the 54 men, 14 (25.9%) had the LL genotype, 29 (53.7%) had the SL genotype, and 11 (20.4%) had the SS genotype. In the 92 controls, the LL, SL, and SS genotypes were present in 27 (29.3%), 41 (44.6%), and 24 (26.1%), respectively. No statistically significant differences were found in 5-HTTLPR allelic variations or in 5-HTTLPR gene variations. In all men treated with 20 mg paroxetine, analysis of variance of the natural logarithm of fold increase in the IELT showed no statistically significant difference according to genotype (p=0.83).

Conclusions: The 5-HTTLPR polymorphism is not associated with daily 20-mg paroxetine treatment-induced ejaculation delay in men with LPE.

Keywords: 5-HTTLPR polymorphism; Ejaculation delay; Lifelong premature ejaculation; Paroxetine; SSRIs.

FIG. 1

Distribution of fold increase (FI) of the geometric mean intravaginal ejaculation latency time (IELT) on daily paroxetine 20-mg treatment in men with lifelong premature ejaculation: 20% had no paroxetine-induced ejaculation delay (FI, 0-2), whereas 80% had an ejaculation delay (FI, >2).

FIG. 2

Photograph of DNA fragments on a gel under ultraviolet light. Lane 1, patient homozygous for the L allele (LL); lane 2, patient homozygous for the S allele (SS); lane 3, heterozygous patient (LS).