The aim of this study was to determine the incidence and characteristics of
pain following intracavernous injection of
prostaglandin E1 (
PGE). We injected
PGE into the cavernous tissues of 156 patients with
erectile dysfunction who had never previously been injected with
PGE. The incidence and characteristics of
pain after injection were evaluated by the patients' response to a questionnaire. The intensity of
pain was determined by the degree of impediment to intercourse, verbal rating scale (VRS), numerical rating scale (NRS), and visual analogue scale (VAS). Patients scoring 'no
pain' on the VRS, NRS, and VAS were 11.5%, 7.7%, and 7.7%, respectively. Overall incidence of
pain was 91%. There was 'much' or 'very much' impediment to intercourse because of
pain in 14 (9.1%) patients. The most common kind of
pain was 'heavy
pain' in 90% of the patients followed by 'throbbing' in 38%, 'aching' in 21%, 'tightening' in 18%, and 'shooting' in 13%. The mean duration of
pain was 101.2 +/- 63.7 minutes and it lasted during the entire erection period in 71(50.4%) patients. There were significant correlations among the degree of impediment to intercourse, VRS, NRS, and VAS scores (all p < 0.01). However, no association was noted between
pain intensity and both erectile response to
PGE and injected dose. The higher incidence of intracavernous
PGE-induced
pain reported here compared to other studies might be related to difference in pain thresholds among races. The high incidence of
pain but low frequency of much impediment to intercourse would be related to the
pain characteristics as well as the intensity of
pain.