An 89‐year‐old with stage 0 CLL and a history of stage III colorectal cancer treated with hemicolectomy and capecitabine in 2003 was admitted to the hospital in 2006. She felt dehydrated, nauseated, and constipated. For 4 days prior to admission, she felt unable to initiate urination. She denied fevers, chills, abdominal pain, or a loss of appetite. While waiting in the ED, she finally urinated. She had no evidence of recurrent cancer, with normal colonoscopy and a screening CT scan in 2005. Her home medications included solifenacin 5 mg once daily (started 10 days prior to admission), metoprolol, levothyroxine, and lisinopril/HCTZ. The patient appeared nontoxic, with hypoactive bowel sounds and mild, diffuse abdominal tenderness. No peritoneal signs were present. Her admission serum BUN and Cr were 90 and 3.4 mg/dL, respectively, compared with 18 and 0.8 mg/dL, respectively, 2 months prior. CT scan results were consistent with a small bowel obstruction. A PET scan and renal ultrasound were normal. With cessation of solifenacin and lisinopril/HCTZ and hydration, her constipation, ARF, and feeling of urinary retention resolved. After 4 days, she tolerated a diet, and her colostomy output normalized. Eight months later, her Cr and abdominal CT were normal.
The patient had a small bowel pseudo‐obstruction and the feeling of urinary retention from soli‐fenacin, an antimuscarinic that treats bladder overactivity. In 4 randomized trials, only 189 patients of the 1811 who received active drug were more than 75 years old. Healthy elderly patients 64‐78 years of age who received 2 weeks of treatment with solifenacin 5 and 10 mg had a mean AUC‐24 that was “approximately 20%” higher than that in younger subjects. In the four 12‐week clinical trials in which 1158 patients were treated with solifenacin 10 mg, there were 3 serious intestinal adverse events: fecal impaction, colonic obstruction, and intestinal obstruction. Patients receiving solifenacin were more likely to experience constipation than those given placebo.
Given the dearth of clinical data on patients > 75 years old, the effects of age on the pharmacokinetics, the higher likelihood of bowel pathology in the elderly, the increased risk of solifenacin‐induced side effects in the pooled analysis of patients ≥ 65 years old, and given the minor clinical benefit of solifenacin, physicians should seriously consider whether its benefits outweigh its risks.
L. Feldman, none; N. Pemmaraju, none.
To cite this abstract:Feldman L, Pemmaraju N. Solifenacin‐lnduced Small Bowel Pseudo‐obstruction. Abstract published at Hospital Medicine 2008, April 3-5, San Diego, Calif. Abstract 140. https://www.shmabstracts.com/abstract/solifenacinlnduced-small-bowel-pseudoobstruction/. Accessed December 10, 2018.