"i have severe leg pain caused by renal failure and i have arthritic knee joints. i was taking solpadol effervescent for 3 years but the sodium caused high blood pressure (be warned) i went on to tramadol 50mg but after 3 months use i was feeling unwell on wakening from a nights sleep so i stopped use and suffered terrible withdrawal symptoms nervousness, unable to sleep, anxiety and pain. i was prescribed tramadol slow release (sr) capsules 100mg and they have been brilliant for pain, no problems for at least 5 years. recommended."