Severe spruelike enteropathy associated with olmesartan observed by double-balloon enteroscopy

Systematic review: Clinical phenotypes, histopathological features and prognosis of enteropathy due to angiotensin II receptor blockers

BACKGROUND

Although enteropathy due to angiotensin II receptor blockers (ARBs) has been known for over 10 years, clinicians' awareness of this condition is still low.

AIMS

To systematically review the literature about clinical phenotypes, distribution of mucosal changes throughout the gastrointestinal tract and prognosis of enteropathy due to ARBs.

METHODS

According to PRISMA guidelines, we searched PubMed and Embase for relevant articles up to November 6, 2023. We included full-text papers, letters, case reports and case series describing enteropathy due to ARBs. Patients were classified into subgroups based on endoscopic and histological findings of different regions of the gastrointestinal tract. The protocol was registered with Open Science Framework (https://doi.org/10.17605/OSF.IO/TK67C).

RESULTS

We included 94 articles reporting 183 cases (101 female, mean age at diagnosis 69 ± 10 years). The clinical picture at diagnosis was characterised by severe diarrhoea (97%) and weight loss (84%, median -13 kg), leading to hospital admission in 167 (95%) patients. Olmesartan (90%) was most frequently implicated. Villous atrophy (VA) was reported in 164/183 (89%) patients. One hundred and nine had only VA, 12 had pan-gastrointestinal involvement, 23 had VA and gastric involvement and 19 had VA and colon involvement (predominantly microscopic colitis). Outcomes were reported for 178/183 (97%) patients, who all recovered clinically on ARBs withdrawal. Histological recovery occurred in all 96 patients with VA at baseline who underwent follow-up duodenal biopsy.

CONCLUSIONS

Enteropathy due to ARBs is characterised by severe malabsorption often requiring hospital admission and can involve the entire gastrointestinal tract. Clinician awareness can lead to prompt diagnosis and excellent prognosis.

Severe spruelike enteropathy and collagenous colitis caused by olmesartan

BACKGROUND

Olmesartan, which is an angiotensin II receptor blocker, reportedly causes spruelike enteropathy, with intestinal villous atrophy as its typical histopathological finding. Interestingly, collagenous and/or lymphocytic gastritis and colitis occur in some patients. We report the case of a 73-year-old Japanese man with a 2-month clinical history of severe diarrhea and weight loss. There were few reports in which spruelike enteropathy and collagenous colitis were both observed and could be followed up.

CASE PRESENTATION

We report a case of a 73-year-old man with a 2-month clinical history of severe diarrhea and weight loss. He had taken olmesartan for hypertension treatment for 5 years. Endoscopic examination with biopsies revealed intestinal villous atrophy and collagenous colitis. Suspecting enteropathy caused by olmesartan, which was discontinued on admission because of hypotension, we continued to stop the drug. Within 3 weeks after olmesartan discontinuation, his clinical symptoms improved. After 3 months, follow-up endoscopy showed improvement of villous atrophy but not of the thickened collagen band of the colon. However, the mucosa normalized after 6 months, histologically confirming that the preexistent pathology was finally resolved.

CONCLUSIONS

This report presents a case in which spruelike enteropathy and collagenous colitis were both observed and could be followed up. In unexplained cases of diarrhea, medication history should be reconfirmed and this disease should be considered a differential diagnosis.

Linalyl acetate prevents olmesartan-induced intestinal hypermotility mediated by interference of the sympathetic inhibitory pathway in hypertensive rat

Olmesartan-associated enteropathy (OAE) is a life-threatening pathological condition, but its underlying mechanisms have not been elucidated. Although intestinal hypermotility is frequently accompanied by chronic diarrhea, there have been no studies of olmesartan-induced hypermotility. Intestinal motility should be well regulated by the enteric nervous system, but degeneration of enteric neurons has been reported in patients with chronic diarrheal diseases, such as irritable bowel syndrome, suggesting a connection between OAE and intestinal hypermotility. In this study, interference with this inhibitory pathway was analyzed in a model of olmesartan-induced intestinal hypermotility (OIH) in rats with nicotine-induced hypertension exposed to chronic immobilizing stress. The effects of the potent inhibitory neurotransmitters norepinephrine (NE) and sodium nitroprusside (SNP), which act via different pathways, were assessed ex vivo, with only NE-modulated frequency and amplitude of spontaneous contractions found to be elevated in OIH rat jejunum. Clinical symptoms frequent in OAE, including atrophy of the intestinal epithelium and weight loss, were observed in these rats. Interestingly, olmesartan significantly elevated heart rate while lowering blood pressure in OIH rats. These abnormal conditions were prevented by adding linalyl acetate (LA), while the blood pressure-lowering effects of olmesartan were maintained. These findings suggest that olmesartan induces intestinal hypermotility by interfering with the sympathetic inhibitory pathway, and reduces epithelial cell size or body weight in hypertensive rats. As LA prevented these effects, combination treatment with olmesartan plus LA may provide better antihypertensive efficacy without inducing OAE.