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Sildenafil use, sexual risk behavior, and risk for sexually transmitted diseases, including HIV infection.

Swearingen SG, Klausner JD.

STD Prevention and Control Services, San Francisco Department of Public Health.

PURPOSE: To determine the rates of sildenafil (Viagra) use among different populations, primarily among men who have sex with men, and to measure the association of sildenafil use with increased sexual risk behavior and sexually transmitted diseases (STDs), including human immunodeficiency virus (HIV) infection. METHODS: The National Center for Biotechnology Information PubMed was searched using a variety of terms for relevant publications from January 1999 to July 2004. In addition, all scientific abstracts from national and international conferences on STDs from January 1999 to July 2004 were searched. Relevant journal articles and scientific abstracts presenting original data and meeting given criteria were included. RESULTS: Fourteen studies met the inclusion criteria. Seven of the 11 studies in men who have sex with men showed sildenafil use rates >10% (range 3%-32%). Increased odds of unprotected anal sex with a partner of unknown or serodiscordant HIV status ranged from 2.0 to 5.7 times (mean = 3.9) for sildenafil users versus nonusers. The risk of sildenafil use and STD diagnosis among HIV-positive men who have sex with men was 1.92 (P = 0.05), and the odds of sildenafil use among those newly HIV infected was 2.5 (95% CI 1.1-4.1). CONCLUSIONS: Most studies reported frequent sildenafil use in men who have sex with men, and several showed independent associations between use of the drug and sexual risk behavior, as well as an increased risk for STDs, including incident HIV infection. Although future research among more varied participants is needed, these results warrant a multi-faceted response to reduce the misuse of sildenafil and its consequences, particularly among men who have sex with men.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15922685&query_hl=1

Pharmacological preconditioning with sildenafil: Basic mechanisms and clinical implications.

Kukreja RC, Salloum F, Das A, Ockaili R, Yin C, Bremer YA, Fisher PW, Wittkamp M, Hawkins J, Chou E, Kukreja AK, Wang X, Marwaha VR, Xi L.

Division of Cardiology, Department of Internal Medicine, Virginia Commonwealth University, P.O. Box 980281, 1101 East Mashall Street, Room 7-046, Richmond, VA 23298-0281, USA.

The phosphodiesterase type-5 (PDE5) inhibitor, sildenafil, is the first drug developed for treatment of erectile dysfunction in patients. Experimental data in animals show that sildenafil has a preconditioning-like cardioprotective effect against ischemia/reperfusion injury in the intact heart. Mechanistic studies suggest that sildenafil exerts cardioprotection through NO generated from eNOS/iNOS, activation of protein kinase C/ERK signaling and opening of mitochondrial ATP-sensitive potassium channels. Additional studies show that the drug attenuates cell death resulting from necrosis and apoptosis, and increases the Bcl2/Bax ratio through NO signaling in adult cardiomyocytes. Emerging new data also suggest that sildenafil may be used clinically for treatment of pulmonary arterial hypertension and endothelial dysfunction. Future demonstration of the cardioprotective effect in patients with the relatively safe and effective FDA-approved PDE5 inhibitors such as sildenafil could have an enormous impact on bringing the long-studied phenomenon of ischemic and pharmacologic preconditioning to the clinical forefront.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15922255&query_hl=1
Time effect window of sildenafil for the treatment of erectile dysfunction]

[Article in Chinese]

Zhang B, Qi T.

Department of Infertility and Sexual Medicine, the Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510630, China. doctorzb@163.com

The therapeutic efficacy of sildenafil for the treatment of erectile dysfunction is correlative with the pharmacokinetics of the drug and the time of sexual behavior. More and more researches on the time effect window of sildenafil for the treatment of erectile dysfunction have elucidated the least time to achieve sufficient penile hardness for intercourse and to reach the best erectile state after the drug administration, as well as the therapeutic effect of the long-term treatment with the drug.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15921268&query_hl=1
Advances in the treatment of erectile dysfunction by viagra]

[Article in Chinese]

Xu QQ, Zhu JC.

Department of Urology, Peking University Peoples Hospital, Beijing 100044, China. xuangle@yahoo.com.cn

Viagra has become the first line drug for the treatment of erectile dysfunction since it was first introduced in 1998. Its efficacy and safety have been sidely acclaimed as being definite. This article presents a brief review about the advances in the studies of Viagra, including its therapeutic effect and safety, its protection of penile health, and its promotion of self-esteem and sexual relationship.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15921267&query_hl=1