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Drug combinations in the therapy of low response to phosphodiesterase 5 inhibitors in patients with erectile
Udo Dunzendorfer1, Arne Behm, Eva Dunzendorfer
1Maingau Hospital, J.-W.-G.-University Frankfurt, D 60318 Frankfurt, Scheffelstr. 2-16, Germany.
Abstract:
Combinatorial drugs utilising a clinically-proven single agent approach in erectile dysfunction (ED) have led to the search for additional compounds to improve therapy and the safety profile. Selective inhibitors of Phosphodiesterase type 5, such as Sildenafil, demonstrate a defined failure rate in ED. The therapeutic concept to increase blood influx and or to decrease blood efflux in patients with ED under therapy encountered severe drawbacks. It appeared impossible to decrease the NO-content in the corpora cavernosa and associated organs followed by synchronized increase of NO by a second drug. One has to metabolically activate cAMP by the first acting compound followed by cGMP stimulation. The pharmacology of the counteractive drugs was investigated clinically and a combination of 50 mg sildenafil with 5 mg dihydro-ergotamine (DHE) was identified as of practical use in patients with low response to Sildenafil. The safety profile appeared to be improved by this combination therapy. The present study is a clinical follow-up of patients treated with different therapeutical regimens to document the effectiveness of Sildenafil in combination with DHE.
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