Drugs affecting Bowel Habit

Question 1

Drugs affecting Bowel Habit - Example Question

Answer 1

A 62-year-old woman comes to the gastroenterology clinic for review. She has a history of watery diarrhoea over the course of the past 6 months, where she is opening her bowels some 4-6 times per day. There is other past medical history of hypertension, ischaemic heart disease, Type 2 diabetes and depression.

Investigations

Hb 11.5 g/l Na+ 139 mmol/l Bilirubin 12 µmol/l
Platelets 207 * 109/l K+ 3.9 mmol/l ALP 95 u/l
WBC 8.9 * 109/l Urea 7.2 mmol/l ALT 23 u/l
Neuts 5.6 * 109/l Creatinine 100 µmol/l γGT 56 u/l
Lymphs 1.8 * 109/l Albumin 38 g/l
Eosin 0.5 * 109/l

Colonoscopy: Mild mucosal oedema only, biopsy reveals lymphocytic infiltration

Which of the following agents is most likely to be the cause of her colonoscopy findings?

	Amlodipine
	Atorvastatin
	Lisinopril
	Metformin
	> Sertraline

Sertraline is recognised as highly likely to be associated with lymphocytic colitis, (microscopic colitis associated with lymphocytic infiltration). This conclusion results from a mix of association / epidemiology studies, and case series where removal and re-introduction of medication has been correlated with symptoms and changes in biopsy appearance.

Ref: Münch A, Aust D, Bohr J, et al. Microscopic colitis: Current status, present and future challenges: statements of the European Microscopic Colitis Group. J Crohns Colitis 2012; 6:932

Calcium channel antagonists are not thought to be associated with microscopic colitis, but are uncommonly reported as leading to change in bowel habit including diarrhoea. Metformin leads to bile salt malabsorption which may result in diarrhoea. Statins may be associated with microscopic colitis, although withdrawal and re-challenge evidence is less strong than for sertraline. ACE inhibitors are not known to be associated with microscopic colitis. Diarrhoea was a commonly reported adverse event in lisinopril clinical trials, but this is not thought to be due to microscopic colitis.

Question 2

Sertraline and Lymphocytic Colitis

Answer 2

Sertraline is recognised as highly likely to be associated with lymphocytic colitis, (microscopic colitis associated with lymphocytic infiltration). This conclusion results from a mix of association / epidemiology studies, and case series where removal and re-introduction of medication has been correlated with symptoms and changes in biopsy appearance.

Statins may be associated with microscopic colitis, although withdrawal and re-challenge evidence is less strong than for sertraline.

Question 3

Drugs affecting Bowel Habit

Answer 3

Sertraline is recognised as highly likely to be associated with lymphocytic colitis, (microscopic colitis associated with lymphocytic infiltration)

Calcium channel antagonists are uncommonly reported as leading to change in bowel habit including diarrhoea.

Metformin leads to bile salt malabsorption which may result in diarrhoea.

Statins may be associated with microscopic colitis, although withdrawal and re-challenge evidence is less strong than for sertraline.

ACE inhibitors are not known to be associated with microscopic colitis. Diarrhoea was a commonly reported adverse event in lisinopril clinical trials, but this is not thought to be due to microscopic colitis.