An open-label study of chronic polyethylene glycol laxative use in chronic constipation

Polyethylene glycol 3350 (MiraLAX, Braintree Laboratories Inc., Braintree, MA, USA) is approved for the short-term treatment of occasional constipation.

To extend the safety data of polyethylene glycol used for chronic treatment of chronic constipation.

Study subjects who met defined criteria for chronic constipation were enrolled in this open-labelled, single-treatment multi-centre study to receive polyethylene glycol laxative as a single daily dose of 17 g for 12 months. Subjects returned to their study centres after 2, 4, 6, 9 and 12 months of treatment where blood and urine samples were collected and adverse events were reviewed. At each visit, subjects were queried for ROME constipation criteria and they rated their overall improvement using a global efficacy scale.

311 patients including 117, age 65 and older, were enrolled and received treatment at one of 50 centres. One hundred and eighty-four completed all 12 months of treatment. With respect to the 'Global Efficacy Assessment', depending on the month of observation, 80-88% of enrolled patients, and 84-94% of the elderly, were treated successfully. Similar results were obtained from secondary efficacy measures that assessed individual ROME constipation criteria at each visit. The response to treatment was durable over time. Over the 1-year course of study representing 218 patient-years at the labelled dose, medication-associated adverse effects were gastrointestinal complaints of diarrhoea, loose stool, flatulence and nausea. These effects were generally mild or moderate in severity. There were no clinically significant changes in haematology or blood chemistry, particularly electrolytes, for the study population as a whole or the elderly group.

Polyethylene glycol laxative is safe and effective for treating constipation in adult and elderly patients for periods up to 12 months, with no evidence of tachyphylaxis.