Objective: Here is the first off label clinical trial presenting the result of PDE-5 inhibitors as an adjuvant for the pharmacological treatment of low back pain. However, controlled randomized trials proving the efficacy of this approach for the treatment of low back pain is lacking. The results of such studies confirming the current encouraging findings regarding the use of PDE-5 inhibitors as a new treatment for low back pain.

Materials and Methods: 136 female patients were selected. 61-diagnosed with failed back surgery syndrome, 45-with chronic degenerative disc disease, 29-with lumbar facet joint and SI joint arthropathy, and 1- with low back congenital malformation. Patients were treated with oral opioids, muscle relaxant, COX-2 inhibitors and selectively SSRI. This study continued for 6 months.

Results: 95 patients (70%) reported decrease numerical pain score (NPS) from 20 to 40% just with an addition of Viagra or Cialis to they treatment plan. 60 patients (44%) reported increase of flexibility in lumbar area. 49 patients (36%) requested decrease amount of opioids from 20 to 30%. 33 patient (24%) reported the sensation of internal heat in pelvic and lumbar area. 9 patients (6,5%) did not notice any difference compared with standard medical treatment and 7 patients (5%) developed different complications (headache and nose congestion) that required discontinuation of this treatment.

Discussion: PDE 5 Inhibitors relax smooth muscle and increase regional blood flow in pelvic and lumbar areas simply redirecting cardiac output. This allows lower body receives more blood flow i.e. enhanced exposure to circulating medications. The study result showed that for the selective group of patients with chronic low back pain on oral opioid therapy the addition of PDE 5 Inhibitors allowed lowering of the pain score down to 20-40%, increased flexibility in lumbar area to 44% and decreased the amount of opioids to 25%.