Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter to the Editor
  • Published:

Comment on: ‘Inhibition of phosphodiesterase 11 (PDE11) impacts on sperm quality’

International Journal of Impotence Research volume 17, page 387 (2005)Cite this article

We thank Pomara et al for their interest and favorable comments, and we wish to address several points that they raised in response to our article, ‘High biochemical selectivity of tadalafil, sildenafil and vardenafil for human phosphodiesterase 5A1 (PDE5) over PDE11A4 suggests the absence of PDE11A4 cross-reaction in patients.’

Pomara et al suggest that the 40-fold selectivity of tadalafil for PDE5 over PDE11A4 may not be sufficient to avoid crossreactivity in patients. They point to the reported 41-fold selectivity of sildenafil for PDE5 over PDE1, which they say may not be sufficient since sildenafil effects on PDE1 could explain the vasodilation, flushing and tachycardia that have been reported for sildenafil. However, since vasodilation and other hemodynamic effects such as flushing are common side-effects of all PDE5 inhibitors,1, 2, 3 they are more likely to be PDE5-specific effects than PDE1-specific effects. We are not aware of confirmed clinical reports showing that any of the approved PDE5 inhibitors causes significant tachycardia when used as directed. We agree that a 40-fold selectivity of tadalafil for PDE5 over PDE11A4 does not completely exclude the possibility of crossreaction, but it reduces the likelihood of such an effect when compared with the five-fold tadalafil selectivity reported for the shortest isoform, PDE11A1.4

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

References

  1. Bischoff E . Vardenafil preclinical trial data: potency, pharmacodynamics, pharmacokinetics, and adverse events. Int J Impot Res 2004; 16(Suppl 1): S34–S37.

    Article  CAS  Google Scholar 

  2. Cheitlin MD et al. Use of Sildenafil (Viagra) in patients with cardiovascular disease. J Am Coll Cardiol 1999; 33: 273–282.

    Article  CAS  Google Scholar 

  3. Kloner RA . Cardiovascular effects of the 3 phosphodiesterase-5 inhibitors approved for the treatment of erectile dysfunction. Circulation 2004; 110: 3149–3155.

    Article  Google Scholar 

  4. Gbekor E et al. Selectivity of sildenafil and other phosphodiesterase type 5 inhibitors against all human phosphodiesterase families. Eur Urol 2002; 1(Suppl 1): 63.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA

    J L Weeks II

Authors
  1. J L Weeks II
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to J L Weeks II.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Weeks, J. Comment on: ‘Inhibition of phosphodiesterase 11 (PDE11) impacts on sperm quality’. Int J Impot Res 17, 387 (2005). https://doi.org/10.1038/sj.ijir.3901306

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/sj.ijir.3901306

Search

Advanced search

Quick links