Effectiveness of Gabapentinoids for Cancer-related Rectal and Vesical Tenesmus: Report of Four Cases

Gabapentinoids could be assumed to relieve cancer-related rectal/vesical tenesmus based on their pharmacological mechanism. Four patients were refractory for cancer-related rectal/vesical tenesmus although their opioid doses were titrated up. Symptom intensity difference (SID) between initiation and follow-up after 24, 48, and 72 h and daily changes in the frequency of urination, defecation, opioid rescue doses, presence of sleep disruption, and dose of regular opioid medication were evaluated. The median reductions in daily discomfort measured as SID between baseline and follow-up after 24, 48, and 72 h were 87.5%, 70.0%, and 80.0%, respectively, while those in daily pain intensity were 75%, 66.7%, and 66.7%, respectively. The initiation dose of gabapentin was 200 or 400 mg/day and that of pregabalin was 75 mg/day in one patient. Gabapentinoids were effective at low doses administered over a short duration to patients with refractory cancer-related rectal/vesical tenesmus.