Diltiazem for the management of malignancy-associated perineal pain and tenesmus.

BACKGROUND: Perineal pain is a frequent complaint of patients with advanced cancer (colorectal, genitourinary, prostate), and often quite difficult to manage with significant impact on quality of life. Calcium channel blockers (CCBs) are potent inhibitors of intestinal smooth muscle contraction and have been shown to impact tone and motility of the gastrointestinal tract. As such, they have been used in various pain syndromes of the lower gastrointestinal tract, such as chronic anal fissure, to promote healing and improve pain. Here we describe two cases using oral diltiazem for malignancy-associated perineal pain and tenesmus.

DISCUSSION: The first case describes an elderly male with advanced urothelial cancer post surgical resection and chemoradiation who suffered from rectal pain described as "sitting on a football" despite nerve blocks and oral opioids. He experienced dramatic improvement in pain scores and daily requirements of oral analgesics after starting oral diltiazem. The second case describes a middle-aged female with rectal cancer post surgical resection and chemoradiation who suffered from quality-of-life-limiting rectal pain and pressure despite oral opioids. She experienced dramatic improvement in the "pressure-type" pain after adding oral diltiazem.

CONCLUSION: Based on our experience with these two cases, we propose oral diltiazem for use as an adjunct therapy for management of chronic malignancy-associated perineal pain, specifically with characteristics of pressure-type pain and tenesmus.